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FUNCTIONALIZED AND CROSSLINKED MATERIALS

20250205680 ยท 2025-06-26

    Inventors

    Cpc classification

    International classification

    Abstract

    Functionalized and crosslinked material, which may optionally be employed as a sorbent, as well as methods of making such materials and systems of using such materials are provided. The processes, methods, systems and materials herein can be used for the separation of carbon dioxide from fluid streams. In one aspect, a method of forming functionalized crosslinked particles comprises introducing at least a portion of a surface of each porous particle in at least a subset of a plurality of porous particles to a crosslinking agent and a first reagent comprising at least one adsorbing moiety. Examples of adsorbing moiety include silane-functionalized amines, amino-functionalized silanes (aminosilane), and polyamines. In some aspects the method further comprises introducing the porous particles to a second reagent comprising at least one interaction moiety such as a silane-functionalized amine, amino-functionalized silane (aminosilane), or polyamine. Examples of crosslinking agent include dialdehyde, diisocyanates, dihaloalkane, diepoxide and dianhydrides.

    Claims

    1. A method of forming a plurality of functionalized crosslinked particles, the method comprising: introducing at least a portion of a surface of each porous particle in at least a subset of a plurality of porous particles to (i) a crosslinking agent and (ii) a first reagent comprising at least one adsorbing moiety.

    2. The method of claim 1 wherein the adsorbing moiety is a first silane-functionalized amine, a first amino-functionalized silane (aminosilane), or a first polyamine.

    3. The method of claim 1, wherein the introducing further comprises introducing the at least the portion of the surface of each porous particle in at least the subset of a plurality of porous particles to a second reagent comprising at least one interaction moiety.

    4. The method of claim 3, wherein the at least one interaction moiety is other than the adsorbing moiety and is a second silane-functionalized amine, a second amino-functionalized silane (aminosilane), or a second polyamine.

    5. The method of claim 1, wherein the crosslinking agent is a multivalent crosslinking agent.

    6. The method of claim 1, wherein the crosslinking agent comprises a structure having one of formulas VII, VIIa, VIIb, VIIc, VIId, VIIe, VIIf, VIIg, VIIh, VIIi, VIIj, VIIk, VIII, or VIIm.

    7. The method of claim 1, wherein the crosslinking agent is a dialdehyde, wherein the dialdehyde is 2,5-diformylfuran, glutaraldehyde, glyoxal, 1,3-phenylenediacetaldehyde, or mixtures thereof, or wherein the crosslinking agent is a diisocyanate, wherein the diisocyanate is 2,4-diisocyanatotoluene, methylene diphenyl diisocyanate (4,4-diisocyanatodiphenylmethane), hexamethylene diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, xylylene diisocyanate, or mixtures thereof, or wherein the crosslinking agent is a dihaloalkane, wherein the dihaloalkane is 1,4-dibromobutane, 1,2-dibromoethane, 1,5-dibromopentane, or mixtures thereof, or wherein the dihaloalkane has the formula: ##STR00050## wherein X.sub.1 and X.sub.2 are each, independently, F, Cl, Br, I, and n is 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, or wherein the crosslinking agent is a diepoxide, wherein the crosslinking agent is diglycidyl ether, ethylene glycol diglycidyl ether, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, Neopentyl Glycol Diglycidyl Ether, or mixtures thereof, or wherein the crosslinking agent is a dianhydride, or wherein the crosslinking agent is methylene dianhydride (MDA; 2,2-oxydioxydiethanone), benzophenone-3,3,4,4-tetracarboxylic dianhydride (2,2-(4-oxocyclohexa -2,5-dien-1-ylidene)bis(benzenecarboxylic acid), 3,3,4,4-biphenyl dianhydride (2,2-dicarboxy-4,4-dioxo-[1,1-biphenyl]-3,3-dicarboxylic acid anhydride), 4,4-oxydiphthalic anhydride, 1,2,3,4-cyclohexane tetracarboxylic dianhydride, or mixtures thereof, or wherein the crosslinking agent is a diacid chloride, wherein the diacid chloride is succinyl chloride, glutaryl chloride, adipoyl chloride, sebacoyl chloride, 4,4-oxydiphthaloyl chloride, terephthaloyl chloride, or mixtures thereof.

    8.-22. (canceled)

    23. The method of claim 1, further comprising, prior to the introducing, exposing the plurality of porous particles to a third reagent comprising a polymer, thereby coating the plurality of porous particles.

    24. The method of claim 23, after the exposing and before the introducing, drying the plurality of porous particles in a vacuum oven at between 50 C. and 100 C. until a hydration threshold of less than 5% (wt/wt) of water to the plurality of particles is reached.

    25. The method of claim 23, wherein the polymer is poly(vinyl alcohol) (PVA).

    26. The method of claim 1, wherein the plurality of porous particles are in a solvent during the introducing, and wherein a ratio of solvent to the plurality of porous particles at the onset of the introducing is between 1.5 wt/wt and 4:1 wt/wt of the solvent to the plurality of porous particles.

    27. The method of claim 1, wherein the crosslinking agent is in a first solvent during the introducing, wherein a ratio of crosslinking agent to the plurality of porous particles at the onset of the introducing is up to 15% (wt/wt) of the crosslinking agent to the plurality of porous particles.

    28. The method of claim 1, wherein the crosslinking agent is in a first solvent during the introducing, wherein a ratio of crosslinking agent to the plurality of porous particles at the onset of the introducing is up to 50 mol % of the crosslinking agent to the second reagent.

    29. The method of claim 1, wherein the first reagent is in a second solvent during the introducing, wherein a ratio of the first reagent to the second solvent is between 20% to 80% (wt/wt) of the first reagent to the plurality of porous particles.

    30. The method of claim 1, wherein the at least one adsorbing moiety of the first reagent comprises an aminosilane.

    31.-43. (canceled)

    44. The method of claim 1, the method further comprising drying the functionalized crosslinked particles to a hydration threshold of less than about 5% (wt/wt) of a solvent medium to the functionalized, crosslinked particles.

    45. A composition comprising a plurality of crosslinked particles modified according to the method of claim 1.

    46.-50. (canceled)

    51. The composition of claim 45, wherein the composition has a 50% strain crush strength of at least 1.5 MPa.

    52.-55. (canceled)

    56. The composition of claim 45, wherein the plurality of porous particles have (i) a distribution of pore sizes from 10 nanometers to 200 nanometers and (ii) a distribution of sieve diameters from 0.4 millimeters to 4 millimeters, or wherein the plurality of porous particles have (i) a distribution of pore sizes from 50 Angstroms to 300 Angstroms and (ii) a distribution of sieve diameters from 0.4 millimeters to 4 millimeters.

    57. (canceled)

    58. A method, comprising using the composition of claim 45 to remove atmospheric CO.sub.2 from air by direct air capture.

    59.-88. (canceled)

    Description

    DESCRIPTION OF DRAWINGS

    [0054] FIGS. 1A-1E are non-limiting schematic illustrations of functionalized, crosslinked materials, in accordance with some embodiments of the present disclosure.

    [0055] FIGS. 2A-2K are chemical illustrations of non-limiting, exemplary compounds, amine moieties, and silane moieties. Provided are illustrations of (A) an aminosilane compound, (B, C) non-limiting amine moieties, (D-G) non-limiting aminosilane compounds, and (H-K) non-limiting polyamine compounds in accordance with some embodiments of the present disclosure.

    [0056] FIGS. 2L-M are chemical illustrations of non-limiting, exemplary crosslinking agents. Provided are illustrations of (L) a dihaloalkane, or (M) an epoxide compound in accordance with some embodiments of the present disclosure.

    [0057] FIGS. 3A-3E are non-limiting flow chart diagrams showing the steps of producing enhanced particles in accordance with some embodiments of the present disclosure.

    [0058] FIGS. 4A-4B are schematic illustrations of (A) an example dip-coating method using a double cone mixing and drying system and (B) an example drying method using a double cone mixing and drying system in accordance with some embodiments of the present disclosure.

    [0059] FIG. 5 is a schematic illustration of an example Nutsche filter mixing/filtration/drying system for producing functionalized particles from particles in accordance with some embodiments of the present disclosure.

    [0060] FIG. 6 is a schematic illustration of an example bag dip-coating system for producing functionalized particles from particles in accordance with some embodiments of the present disclosure.

    [0061] FIG. 7 is a schematic illustration of an example paddle dryer for producing functionalized particles from particles in accordance with some embodiments of the present disclosure.

    [0062] FIG. 8 is a schematic illustration of an example ribbon dryer for producing functionalized particles from particles in accordance with some embodiments of the present disclosure.

    [0063] FIGS. 9A-9B are schematic illustrations of (A) an example drying method using a conveyor dryer and (B) operation of an example drying method in continuous mode in accordance with some embodiments of the present disclosure.

    [0064] FIGS. 10A-10B are schematic illustrations of (A) an exploded view and an assembled view of a non-limiting sample holder for testing sample CO.sub.2 adsorption and (B) a non-limiting experimental setup for testing sample adsorption of CO.sub.2 in accordance with some embodiments of the present disclosure.

    [0065] FIGS. 11A-11B are schematic illustrations of non-limiting, exemplary implementations of a carbon dioxide extraction system in accordance with some embodiments of the present disclosure.

    [0066] FIG. 12 is a schematic illustration of a non-limiting, exemplary implementation of an integrated power and carbon dioxide extraction system in accordance with some embodiments of the present disclosure.

    [0067] FIGS. 13A and 13B illustrate exemplary aminosilanes, in accordance with some embodiments of the present disclosure.

    [0068] FIG. 14 is a line chart depicting CO.sub.2 uptake over a plurality of cycles by a non-limiting functionalized material including a silica substrate, in accordance with some embodiments of the present disclosure. Provided are the testing cycle number (x-axis) and uptake at each cycle (y-axis).

    [0069] FIG. 15 is a schematic illustration of a compression strength test fixture for testing particle samples, in accordance with some embodiments of the present disclosure.

    [0070] FIGS. 16A and 16B are schematic illustrations of an attrition and abrasion test fixture for testing particle samples, in accordance with some embodiments of the present disclosure.

    [0071] In the figures, like references indicate like elements.

    DETAILED DESCRIPTION

    [0072] Amorphous silica is used as a porous structure for functionalization to achieve carbon capture. Silica substrates with amine functionalization, e.g., one or more amine-containing groups covalently bonded on surfaces, achieve reversible capture of carbon dioxide from gaseous mixtures (e.g., the atmosphere). In some embodiments, other porous substrates, such as MOFs, resins, or any described herein, are employed to provide a functionalized material (e.g., a functionalized porous material) that has been functionalized with an adsorbing moiety (e.g., an amine moiety provided by a compound, such as an amine, an aminosilane, a polyamine, a monoamine, or a combination thereof). In certain embodiments, the functionalized material is used as a sorbent.

    [0073] Described herein is a functionalized and crosslinked material (e.g., a functionalized, crosslinked porous material) that has been functionalized with an adsorbing moiety (e.g., an amine moiety provided by a compound, such as an amine, an aminosilane, a polyamine, a monoamine, or a combination thereof) and that has been crosslinked with a linking moiety (e.g., provided by a compound, such as a crosslinking agent). In some embodiments, functionalization further comprises the use of an interaction moiety (e.g., a silane moiety provided by a compound, such as a silane, an aminosilane, and the like). In some embodiments, such moieties (e.g., amine moieties and/or silane moieties) are any compound and any useful combination of two or more compounds (e.g., one or more of amines, aminosilanes, polyamines, monoamines, or any combination of any of these). To enhance lifetime improvement, in some embodiments, the adsorbing moiety and/or the interaction moiety is crosslinked by use of a crosslinker agent and/or is protected from oxidation by use of an oxygen barrier (e.g., provided by way of a polymer coating), an antioxidant, a chelating agent, or a combination of any of these.

    [0074] Many factors can affect the chemical lifetime and/or physical lifetime of sorbents. For example and without limitation, when an amine is employed as the adsorbing moiety, volatilization and/or oxidation of such moieties can minimize its adsorption capacity. Without wishing to be limited by mechanism, amine volatilization is generally a process in which the amine functional group (e.g., on exposed surfaces and in the pores of a substrate) is released from the surface of the substrate during vacuum desorption. Amine volatilization rates are reduced by process controls such as lowering the exposure of the amine-based sorbents to vacuum, elevated temperatures (e.g., >40 C.) and, as described herein, by use of chemical compounds that provide reduced amine volatilization. Without wishing to be limited by mechanism and theory, it has been discovered that a crosslinking agent (e.g., dialdehydes, isocyanates, dihaloalkanes, diepoxides, dianhydrides (e.g., EDTA dianhydride), diacid chlorides, and the like) are used to reduce amine leaching from sorbent and/or to improve physical strength of the sorbent by the presence of crosslinks.

    [0075] Amino oxidation may also be a factor. Without wishing to be limited by mechanism, amine oxidation is generally a process in which the amine functional group (e.g., on exposed surfaces and in the pores of a substrate) can degrade due to oxidation with atmospheric oxygen and/or other Reactive Oxygen Species (ROS), thereby forming a variety of non-functional products. Amine oxidation rates can be reduced by process controls such as lowering the exposure of the amine-based sorbents to oxygen at elevated temperatures (e.g., >40 C.) and, as described herein, by use of chemical compounds that provide reduced amine oxidation.

    [0076] For example and without limitation, amine oxidation can be catalyzed by the presence of oxygen or other oxidative species (e.g., ROS, e.g., but not limited to, superoxide, ozone, hydroxyl radicals, hydroperoxyls). Without wishing to be limited by mechanism and theory, it has been discovered that a polymer (e.g., polyvinyl alcohol (PVA)) disposed on a surface of the substrate can reduce oxidation of adsorbing species, such as an amine-containing functional group. In some embodiments, the polymer coating may serve as an oxygen barrier. Other oxygen barriers may be employed. The oxygen barrier can be provided to be in proximity to the porous substrate of the functionalized material. Without wishing to be limited by mechanism or theory, an oxygen barrier can be employed to extend chemical lifetime (e.g., by blocking oxygen or oxidative species from oxidizing adsorbing moieties) and/or to extend physical lifetime (e.g., by forming a coating on a surface of the porous substrate, thereby enhancing its structural integrity).

    [0077] In another non-limiting embodiment, oxygen or other oxidative species are scavenged by using a chemical antioxidant. Either sacrificial antioxidants or cyclic antioxidants such as hindered amine light stabilizers (HALS) is added, in some embodiments, to the functionalized material to reduce the oxidation of the amines, thereby extending the chemical lifetime of the sorbent. In some embodiments, the antioxidant is provided in any useful component of the functionalized particle. For example and without limitation, in some embodiments the antioxidant is provided in proximity to the surface of the substrate, within the coating of a coated substrate (e.g., a coated particle), and/or in proximity to the functional portion (e.g., an adsorbing moiety, such as an amine) of a functionalized material.

    [0078] In yet another non-limiting embodiment, amine oxidation is e catalyzed by transition metals, such as iron, copper, and the like. In one instance, silica substrates are contaminated with metals, e.g., transition metals, e.g., iron or copper, due to the sand from which they are derived. In various examples, chelating agents are used to chelate or otherwise interact with metals, thereby reducing its oxidative action and extending the chemical lifetime of the sorbent. In some embodiments, the chelating agent is provided in any useful component of the functionalized particle. For example and without limitation, the chelating agent is provided, in some embodiments, in proximity to the surface of the substrate, within the coating of a coated substrate (e.g., a coated particle), and/or in proximity to the functional portion (e.g., an adsorbing moiety, such as an amine) of a functionalized material.

    [0079] Any useful combination of an oxygen barrier (e.g., provided by way of a polymer), an antioxidant, or a chelating agent is employed in some embodiments. For example and without limitation, an oxygen barrier may be used alone or in combination with an antioxidant and/or a chelating agent. In another example, the antioxidant may be used alone or in combination with an oxygen barrier and/or a chelating agent. In yet another example, the chelating agent may be used alone or in combination with an oxygen barrier and/or an antioxidant. Furthermore, the oxygen barrier, antioxidant, and chelating agent may be present in any useful component of the functionalized material, such as in proximity to the surface of the substrate and/or in proximity to the functional portion (e.g., including an adsorbing moiety of the functional portion).

    I. Functionalized Material

    [0080] The present disclosure relates to a functionalized compositions having one or more functional groups. For example and without limitation, an initial material or substrate is functionalized, in some embodiments, to include one or more functional groups (e.g., one or more amine groups) configured to capture carbon dioxide (CO.sub.2). As used herein and without limitation, a monofunctional molecule possesses one functional group (e.g., one reactive group), and a multivalent molecule possess a plurality of functional groups (e.g., a plurality of reactive groups). In some embodiments, the multivalent molecule includes a difunctional (e.g., or bifunctional) molecule possessing two functional groups (e.g., two reactive groups), a trifunctional molecule possessing three functional groups (e.g., three reactive groups), and so forth. In some non-limiting embodiments, the composition has any useful structure (e.g., as a particle), any useful substructure (e.g., one or more pores), and any useful composition (e.g., silica or others described herein). In some non-limiting embodiments, amorphous silica is used as a porous substrate for functionalization to achieve carbon capture. In some embodiments, silica substrates with amine functionalization, e.g., one or more amine-containing moieties covalently bonded on a surface, exhibit reversible capture of carbon dioxide from gaseous mixtures (e.g., the atmosphere). Other substrates and moieties are also described herein, which can provide functionalized compositions for carbon capture.

    [0081] Disclosed herein is a functionalized material (e.g., functionalized porous silica) having a surface modification layer including a linking moiety and a method of producing such protected materials. Also, disclosed herein is a functionalized material (e.g., functionalized porous silica) having a protective polymer coating (e.g., as an oxygen barrier) and a method of producing such protected materials. In turn, the functionalized material is used, in some embodiments, for reversibly capturing (e.g., adsorbing) carbon dioxide (CO.sub.2). In use, the functionalized material is provided, in some embodiments, in any useful format (e.g., as a layer of beads or powder) over or through which gaseous mixtures including CO.sub.2 are flowed. Gas exiting the layer of functionalized material has a lower concentration of CO.sub.2 than the entering gas. During carbon capture adsorption and desorption processes, the functionalized material experiences mechanical attrition through handling, use, and transport through the capture and regeneration processes. Providing a protective polymer coating on the functionalized material (composition) can decrease friability and attrition of the sorbents, leading to longer product life and reduced production of fines. Furthermore, in some embodiments, when the protective polymer coating also serves as an oxygen barrier, the functionalized material (composition) has an extended chemical lifetime due to reduced oxidation.

    [0082] For example, FIG. 1A provides a non-limiting functionalized material (composition) 100A comprises a substrate 102A having a plurality of pores 104A-a, 104A-b. In turn, the surface 103A of the substrate 102A includes a functional portion 106A, which in turn includes an adsorbing moiety 110A (e.g., a CO.sub.2 adsorbing moiety) and an interaction moiety 108A (e.g., a silane-containing interaction moiety). In some embodiments, the functional portion 106A further include other moieties, groups, or molecules to provide an adsorbing material for use as a sorbent. In some embodiments, such moieties, groups, or molecules include an amine group (e.g., NR.sup.N1R.sup.N2, as described herein, which in turn is present in amines, aminosilanes, polyamines, and the like in some embodiments), polymers (e.g., hydrophobic polymers or polyamines), antioxidants, and the like. Furthermore, in some embodiments, such moieties, groups, or molecules form interactions (e.g., covalent and/or non-covalent interactions) between themselves or between itself and the substrate surface.

    [0083] A surface modification layer is disposed, in some embodiments, on at least a portion of the surface 103A. The surface modification layer includes an adsorbing moiety having one or more amine moieties (e.g., any described herein). As seen in FIG. 1A, the surface modification layer includes any useful combination of an adsorbing moiety 110A (e.g., a CO.sub.2 adsorbing moiety) and an interaction moiety 108A. In some embodiments, the material (composition) is configured to adsorb atmospheric CO.sub.2 under a first condition and reversibly desorb adsorbed CO.sub.2 under a second condition. The surface modification layer is disposed, in some embodiments, in proximity to the surface 103A of the substrate 102A.

    [0084] In some embodiments, the surface modification layer include a linking moiety 114A. In general and without limitation, in some embodiments, the linking moiety 114A forms interactions between one or more of the adsorbing moieties, the interaction moieties, the substrate, or a combination thereof. In the example of FIG. 1A, the linking moiety 114Aa forms interactions between the interaction moieties 108A of multiple functional groups 106A, e.g., between the interaction moieties 108A that are each provided on two different functional groups 106A. In such examples, the linking moiety 114Aa is considered difunctional, e.g., comprises two interaction sites. In other examples, the linking moiety 114Ab forms interactions between the interaction moiety 108A and the adsorbing moiety 110A of multiple functional groups 106A, e.g., between the interaction moiety 108A of a first functional group and the adsorbing moiety 110A of a second functional group. In yet other examples, the linking moiety 114Ac forms interactions between the adsorbing moieties 110A of multiple functional groups 106A, e.g., between the adsorbing moieties 110A that are each provided on two different functional groups 106A.

    [0085] The linking agent 114A is shown forming interactions between a portion of the functional groups 106A. In some embodiments, the portion of the functional groups 106A that the linking moieties 114A form interactions is in a range from 0.1 mol % to 50 mol % of the functional groups 106A to the number of moles of amines present.

    [0086] The linking moiety 114A is provided in any useful manner in some embodiments, e.g., by use of one or more crosslinking agents (e.g., any described herein). In some embodiments, the crosslinking agent includes a linking moiety disposed between one or more reactive groups, in which the reactive group is configured to react with an amine functional group (e.g., as provided by an adsorbing moiety 110A).

    [0087] In some embodiments, the linking moiety 114B forms interactions with the surface of the substrate, the adsorbing moieties, and the interaction moieties. As seen in FIG. 1B, in some embodiments the surface modification layer includes an adsorbing moiety 110B (e.g., a CO.sub.2 adsorbing moiety) and the linking moiety 114B. The surface modification layer is disposed, in some embodiments, in proximity to the surface 103B of the substrate 102B. The linking moiety 114B is provided, in some embodiments, by a reaction between a functional group present in the surface modification layer (e.g., an amine group) with a reactive group of any crosslinking agent described herein.

    [0088] In some embodiments, the functional group 106B includes the linking moiety 114B and the adsorbing moiety 110B. In some embodiments, the linking moiety 114B interacts with the surface 103B and the adsorbing moiety 110B. A portion of the functional groups 106B include a linking moiety 114Ba forming interactions between two linking moieties 114B in two functional groups 106B. As shown in FIG. 1B, the functional group 106B is shown crosslinked to functional group 106B-a by a linking moiety 114Ba. In some examples, the linking moiety 114B forms interactions between higher numbers of functional groups 106B, e.g., three or more functional groups 106B. In other examples, the linking moiety 114Bb forms interactions between the linking moiety 114A and the adsorbing moiety 110B of multiple functional groups 106B. In yet other examples, the linking moiety 114Bc forms interactions between adsorbing moieties 110B of multiple functional groups 106B.

    [0089] Optionally, a polymer coating 105C is disposed on the surface 103C, as seen in FIG. 1C. In some embodiments, the polymer, or mixture of polymers, increases the mechanical characteristics of the functionalized, crosslinked, and coated material 100C. One example of the polymer that makes up the polymer coating is polyvinyl alcohol (PVA), a water-soluble synthetic polymer having the formula [CH.sub.2CH(OH)].sub.n, where n is a positive integer (e.g., in the tens, hundreds or thousands, etc.). PVA is readily available from commercial sources and has low toxicity for safe handling during application. The PVA can have a molecular weight (MW) in a range from 10,000 to 200,000 (e.g., in a range from 10,000 to 23,000).

    [0090] In general, the polymer coating 105A is illustratively depicted as a continuous layer on the surface 103A, though in practice there may exist one or more gaps, e.g., holes, in the polymer coating 105A that can facilitate the amines, aitioxidants, or crosslinkers interacting with the surface 103A. Moreover, the substrate has any number of pores that each cause a gap in the polymer coating layer as illustrated in FIG. 1C. Although the polymer coating 105A is a discontinuous layer, in some embodiments, the coating 105A is effective at blocking oxygen by reducing the area of the surface 103A exposed to oxygen.

    [0091] As seen in FIG. 1C, in some embodiments the surface modification layer includes an adsorbing moiety 110C (e.g., a CO.sub.2 adsorbing moiety) and a linking moiety 114C that form a functional group 106C. The surface modification layer is disposed, in some embodiments, in proximity to the surface 103C of the substrate 102C and/or the surface of the polymer coating 105C.

    [0092] Additional examples of polymers that provide the coating include Pebax, polyether block amide (PEBA), polysulfones, polyethersulfones, polyethers, polyamides, ethylcellulose, polyethylene glycol, cellulose acetate, polyurethanes, polystyrenes, polyesters, polyolefins, polyacrylamides, polyacrylates, and combinations, copolymers, and/or block copolymers of those listed herein.

    [0093] A polymer is provided in a coating liquid, in some embodiments, that in turn includes the polymer and a solvent medium (e.g., any described herein). In general, the amount of polymer depends on the type of polymer, the molecular weight of the polymer, the number of amino moieties in the polymer, etc. In some embodiments, the amount of polymer is up to 20% (wt/wt) to the substrate (e.g., silica particles), such as, e.g., up to 15% (wt/wt), up to 10% (wt/wt), up to 8% (wt/wt), less than 12% (wt/wt), or less than 9% (wt/wt). In some embodiments, the amount of polymer(s) is from about 1% to 20% (wt/wt) to the substrate (e.g., from about 1% to 5%, 1% to 10%, 1% to 15%, 3% to 5%, 3% to 10%, 3% to 15%, 3% to 20%, 5% to 10%, 5% to 15%, 5% to 20%, 7% to 10%, 7% to 15%, 7% to 20%, 10% to 15%, 10% to 20%, 1 3% to 15%, 13% to 20%, or 15% to 20% (wt/wt)).

    [0094] In some embodiments, the solvent medium includes water. In some embodiments, the solvent medium includes a polar aprotic solvent or a neutral aprotic solvent. In some embodiments, the solvent medium includes an organic solvent selected from toluene, hexane, cyclohexane, tetrahydrofuran, or mixtures thereof. In some embodiments, the solvent medium includes methanol, cyclohexane, hexane, ethanol, water, or mixtures thereof.

    [0095] The polymer coating is disposed on a surface of the substrate, in some embodiments, to achieve desirable outcomes for the functionalized material under mechanical stresses, such as abrasion. In some embodiments, the polymer coating decreases the attrition of the functionalized material according to one or more standardized testing requirements. Briefly, attrition is the propensity of a product to produce fines in the course of transportation, handling, and use. The polymer coating reduces the attrition such that attrition loss of the particles is 1% or less (e.g., 0.9% or less, 0.8% or less) as measured by ASTM D4058-96 or comparable standards by which attrition, or attrition loss, is quantified. In many examples, the functionalized material is characterized, in some embodiments, by mechanical properties that includes compressive strength. In some embodiments, the functionalized material is durable, e.g., having a crush strength of at least 100 N/mm (e.g., at least 150 N/mm, at least 200 N/mm).

    [0096] In some implementations, the functionalized material includes one or more chelating agents. In some embodiments the chelating agent is present in proximity to the surface 103A of the substrate 102A, the functional portion 106A, the adsorbing moiety 110A (e.g., a CO.sub.2 adsorbing moiety), and/or the interaction moiety 108A. In some embodiments, the chelating agent is present within the polymer coating 105A. In some embodiments the chelating agent interacts with metals present on the surface or pores of the substrate and reduces potential oxidation of the functionalized particles, thereby increasing the chemical lifetime for the functionalized particles to adsorb CO.sub.2. For example, PVA is functional as a chelating agent.

    [0097] Examples of the chelating agent include phosphate-based chelating agents, such as potassium phosphate, or phosphonate-based chelating agent, such as etidronic acid or a salt thereof. Other examples of the chelating agents include metal salts including phosphate (e.g., alkali metal salts, such as sodium phosphate), non-nitrogenous bisphosphonate compounds (e.g., clodronic acid and the like), and nitrogenous biphosphonate compounds (e.g., alendronic acid and the like). In some embodiments, the chelating agent is a bisphosphonate compound including a nitrogen or lacking a nitrogen. In some embodiments, the amount of chelating agent(s) is up to 2% (wt/wt) to the substrate (e.g., silica particles), such as, e.g., up to 0.3% (wt/wt), up to 0.4% (wt/wt), up to 0.6% (wt/wt), or up to 1% (wt/wt). In some embodiments, the amount of chelating agent(s) is from about 0.1% to 5% (wt/wt) to the substrate (e.g., from about 0.1% to 1%, 0.1% to 2%, 0.1% to 3%, 0.1% to 4%, 0.2% to 1%, 0.2% to 2%, 0.2% to 3%, 0.2% to 4%, 0.2% to 5%, 0.5% to 1%, 0.5% to 2%, 0.5% to 3%, 0.5% to 4%, 0.5% to 5%, 1% to 2%, 1% to 3%, 1% to 4%, or 1% to 5% (wt/wt)).

    [0098] In some embodiments, the chelating agent(s) is added during any useful steps of the following synthesis procedure or afterward. In one example, the chelating agent is chelating agent/methanol mixture for 1 hour. In another example, the chelating agent is added to a solution including the polymer employed to form a coating.

    [0099] In some embodiments, the functionalized material includes one or more antioxidants. Without being bound to any particular mechanism or theory, the antioxidant prevents the degradation of amine functional groups by atmospheric oxygen and extends the cycling lifetime of the functionalized material. In some embodiments the antioxidant is present in proximity to the surface 103A of the substrate 102A, the functional portion 106A, the adsorbing moiety 110A (e.g., a CO.sub.2 adsorbing moiety), and/or the interaction moiety 108A. In some embodiments, the antioxidant is present within the polymer coating 105A.

    [0100] Examples of antioxidants for use in the method include sacrificial antioxidants and cyclic antioxidants. Sacrificial antioxidants are generally irreversibly consumed in an oxidation reaction while cyclic antioxidants are regenerable. In some embodiments, the amount of antioxidant(s) in the functionalized material is up to about 5% (wt/wt) to the substrate (e.g., silica particles), such as, e.g., up to 3% (wt/wt), 4% (wt/wt), 6% (wt/wt), or 8% (wt/wt). In some embodiments, the amount of antioxidant(s) is from about 0.1% to 3% (wt/wt) to the substrate (e.g., from about 0.1% to 1%, 0.1% to 2%, 0.1% to 3%, 0.1% to 4%, 0.2% to 1%, 0.2% to 2%, 0.2% to 3%, 0.2% to 4%, 0.2% to 5%, 0.5% to 1%, 0.5% to 2%, 0.5% to 3%, 0.5% to 4%, 0.5% to 5%, 1% to 2%, 1% to 3%, 1% to 4%, or 1% to 5% (wt/wt)).

    [0101] For example, is some embodiments the antioxidant(s) is an organic sulfur-containing compound, such as 2,2-thiodiethanol, 2-hydroxyethyl disulfide, and 3,3-dithiodipropionic acid. In another example, the antioxidant is a hindered amine light stabilizer (HALS) compound. HALS are antioxidant compounds containing an amine functional group and, in some non-limiting embodiments, constitute optionally substituted piperidine compounds. HALS is used, in some embodiments, at low concentrations and neutralize many oxidizing radicals and, in some embodiments, is continually regenerated by heat from the air, CO.sub.2 adsorption, desorber heat. In some embodiments, HALS extends the lifetime of the sorbent longer than sacrificial antioxidants.

    [0102] In some examples, more than one antioxidant is introduced. In such examples, the antioxidants introduced may exhibit synergism, e.g., one antioxidant is regenerated by the second, one antioxidant protects the other by sacrificial oxidation, and/or when the antioxidants exhibit different antioxidant mechanisms.

    [0103] In some embodiments, the antioxidant(s) are added during steps 302A-E, 304B-E, and/or 306A-E of the following synthesis procedure or afterward. In one example, the antioxidant is added through dissolving in methanol, or like organic solvent, and then soaking the substrate in the antioxidant/methanol mixture for between 30 minutes and 5 hours (e.g., 1 hour). In another example, the chelating agent is added to a solution including a reagent (e.g., including an adsorbing moiety) that is employed to form a functionalized material.

    [0104] A functionalized material having any useful combination and number of moieties to facilitate capture of CO.sub.2 is illustrated in FIG. 1D. As seen in FIG. 1D, in some embodiments a surface modification layer includes any useful combination of a first adsorbing moiety 110D (e.g., a first CO.sub.2 adsorbing moiety), a second adsorbing moiety 112D (e.g., a second CO.sub.2 adsorbing moiety), and an interaction moiety 108D, in which the chelating agent and/or the antioxidant is associated with the surface modification layer. In some embodiments, the surface modification layer is disposed in proximity to the surface 103D of the substrate 102D. As described herein, in some embodiments a portion of the functional groups 106D and/or second adsorbing moieties 112D is crosslinked by the linking moiety 114D.

    [0105] As shown in FIG. 1D, the functional group 106D is shown crosslinked to functional group by a linking moiety 114 Da. In some examples, the linking moiety 114 Da forms interactions between the interaction moieties 108D of multiple functional groups 106D. In other examples, the linking moiety 114Dd forms interactions between the interaction moieties 108D and adsorbing moieties 110D of multiple functional groups 106D. In yet other examples, the linking moiety 114Dc forms interactions between adsorbing moieties 110D of multiple functional groups 106D. In other examples, the linking moiety 114Dd forms interactions between first adsorbing moieties 110D and second adsorbing moieties 112D. In yet other examples, the linking moiety 114De forms interactions between interaction moieties 108D and second adsorbing moieties 112D.

    [0106] In some embodiments, a polymer coating is employed with second adsorbing moieties. For example, FIG. 1E provides a non-limiting functionalized material 100E including a substrate 102E having a plurality of pores 104E-a, 104E-b. In turn, the surface 103E of the substrate 102E includes a polymer coating 105E and a functional portion 106E that, in turn, includes a combination of a first adsorbing moiety 110E (e.g., a first CO.sub.2 adsorbing moiety), a second adsorbing moiety 112E (e.g., a second CO.sub.2 adsorbing moiety), and an interaction moiety 108E (e.g., a silane-containing interaction moiety). Optionally, the chelating agent and/or the antioxidant is present in proximity to the surface 103E of the substrate 102E, the functional portion 106E, the first adsorbing moiety 110E (e.g., a first CO.sub.2 adsorbing moiety), the second adsorbing moiety 112E (e.g., a second CO.sub.2 adsorbing moiety), and/or the interaction moiety 108E. In some embodiments, the chelating agent and/or the antioxidant is present within the polymer coating 105E. As described herein, a portion of the functional groups 106E and/or second adsorbing moieties 112E are crosslinked by the linking moiety 114E in some embodiments.

    [0107] In some embodiments, the moieties of a functionalized material are provided in any useful manner. In some embodiments, the surface of a substrate is functionalized by use of a first CO.sub.2 adsorbing compound (e.g., including an aminosilane) and a second CO.sub.2 adsorbing compound (e.g., a polyamine). In turn, in some embodiments, the first CO.sub.2 adsorbing compound provides a first adsorbing moiety (e.g., moiety 110E in FIG. 1E), and the second CO.sub.2 adsorbing compound provides a second adsorbing moiety (e.g., moiety 112E in FIG. 1E).

    [0108] In some embodiments, when the first CO.sub.2 adsorbing compound is an aminosilane, the aminosilane includes a silane moiety as a non-limiting interaction moiety (e.g., interaction moiety 108E in FIG. 1E) and an amine moiety as a non-limiting first adsorbing moiety (e.g., first adsorbing moiety 110E in FIG. 1E). In some embodiments, the aminosilane is covalently bonded to the exterior surface of the substrate (e.g., surface 102E in FIG. 1E) and within the pores (e.g., pores 104E-a, 104E-b in FIG. 1E). Other examples of adsorbing compounds include any compounds described herein (e.g., any aminosilanes or other compounds including one or more amine moieties). In some embodiments, together an aminosilane and a polyamine form a network and provide the stable CO.sub.2 adsorbing function.

    [0109] In some embodiments, the second adsorbing moiety is provided by any useful second adsorbing compound. Examples of adsorbing compounds include any compounds described herein (e.g., any compounds including one or more amine moieties). In some embodiments, any useful combination of second and first adsorbing compounds are employed, and such compounds interact in any useful manner to provide a functionalized network or coating disposed over the surface of the substrate. In turn, in some embodiments, such a network or coating is characterized by any useful combination of adsorbing moieties and interaction moieties.

    [0110] In some embodiments, the second adsorbing moiety is provided with or without a second interaction moiety. In some embodiments the second interaction moiety provides direct or indirect attachment to a surface of the substrate. For example and without limitation, in some embodiments, a polyamine include a plurality of amine moieties and at least one linker disposed between at least two amine moieties (e.g., (R.sup.A-L).sub.n-, in which R.sup.A is an amine moiety, L is a linker, and n is an integer). In some embodiments, the amine moiety R.sup.A acts as an adsorbing moiety. Depending on other components present in the functionalized material, either the amine moiety R.sup.A or the linker L acts as an interaction moiety in some embodiments. For example, in some embodiments an amine moiety R.sup.A of a polyamine interacts with other amine moieties or silane moieties by way of hydrogen bonding or ionic interactions.

    [0111] In some embodiments, the second adsorbing compound is a polyamine, that can include an amine moiety as a non-limiting second adsorbing moiety (e.g., second adsorbing moiety 112E in FIG. 1E). In some embodiments, the second adsorbing moiety is represented by a certain functional group (e.g., an amine group of NR.sup.N1R.sup.N2 or NR.sup.N1 as described herein) or a certain compound having certain functional groups (e.g., a compound including one or more amine groups of NR.sup.N1R.sup.N2 or NR.sup.N1 as described herein). Other examples of adsorbing compounds include any compounds described herein (e.g., any polyamines or other compounds including one, two, or more amine moieties).

    [0112] In some embodiments, the second adsorbing moiety interacts with other functional groups, moieties, or compounds in the functionalization material in various ways. For example and without limitation, in some embodiments, the second adsorbing moiety interacts with the first adsorbing moiety, the interaction moiety, the surface of the substrate, or another second adsorbing moiety. Such interactions include covalent and/or non-covalent bonding interactions (e.g., any described herein). In some embodiments, the second adsorbing moiety interacts with the first adsorbing moiety. In some embodiments, the second adsorbing moiety interacts with the interaction moiety.

    [0113] In some embodiments, the second adsorbing moiety comprises a polyamine or amine moieties from a polyamine. When the first adsorbing moiety is an aminosilane, the polyamine interacts with amine moieties of the aminosilane or interaction moieties of the aminosilane in some embodiments. In some embodiments, amine moieties of the aminosilane and the polyamine interact with silanol groups of the aminosilane through hydrogen bonding and ionic interactions to form a functional group, thereby forming a complex network over the surface of the substrate. Using FIG. 1E as a reference, in some embodiments a functional group 106E includes amine moieties 110E of aminosilane and amine moieties 112E of the polyamine that interact with silanol groups 108E of the aminosilane.

    [0114] In some embodiments, a plurality of adsorbing moieties is provided for the functionalized material. For instance, in some embodiments, a polyamine (e.g., such as polyethyleneimine (PEI)) having a plurality of adsorbing moieties is reacted with the substrate. In some embodiments, the polyamine is characterized by a high interaction surface area that facilitates one dimensional or two dimensional van der Waals interactions with the substrate surface. In some embodiments, the polyamine introduced to the substrate forms a surface modification layer for reversibly binding CO.sub.2 from atmospheric gases. In some embodiments, a polyamine (e.g., PEI having a larger molecular weight such as, e.g., greater than about 800 Da or from about 800 Da to 1 MDa (or 1,000,000 Da)), as compared to short chain amine functionalization) is less volatile overall.

    [0115] In some embodiments, the plurality of adsorbing moieties are provided by way of one or more oligomeric amines or small molecule polyamines or mixtures of any of these. In some embodiments, the oligomeric amine includes an oligomeric ethylene amine or a mixture including such oligomers (e.g., an ethylene amine/oligomer mixture). For example, in some embodiments the oligomer includes ethylene amine-containing molecules (e.g., molecules including a CH.sub.2CH.sub.2NR.sup.N1-group) or oligomers such as H.sub.2N[CH.sub.2CH.sub.2NH], H (e.g., in which n is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more and R.sup.N1 can be any described herein). Tetraethylenepentamine (TEPA) and triethylenetetramine (TETA) are non-limiting examples of oligomeric amines with low volatility. In some embodiments, the oligomeric amine is a small molecule polyamine (e.g., having a molecular weight (MW) between 100 to 800 g/mol). Other examples of oligomers are described herein.

    [0116] In some embodiments, a small molecule amine mixture (e.g., such as Amix 1000) includes amine-containing molecules, such as 2-[(2-aminoethyl)amino]ethanol, (aminoethyl) piperazine, and/or (hydroxyethyl) piperazines as a commercially available mixture of amines.

    [0117] In some non-limiting embodiments, Amix 1000, TEPA, TETA, or a mixture of these or similar compounds is used to functionalize a substrate to form a functionalized material (compound). In some embodiments, Amix 1000, TEPA, TETA, and similar compounds are a low-cost source of reactable amines facilitating low-cost functionalization and carbon capture from atmospheric gases.

    [0118] In some embodiments, the oligomeric amine or small molecule amine mixture is reacted with a porous silica substrate to form a functionalized substrate. In some embodiments, the oligomeric amine or the small molecule amine mixture is a compound bonded to a surface of the substrate and forms a surface modification layer on the surface through van der Waals interactions.

    [0119] Using FIG. 1E as a reference, in some embodiments a functional group 106E includes a polyamine group. In some embodiments, the polyamine group includes one or more primary, secondary, or tertiary amine groups, repeat units of ethylamine or propylamine; or more than one amine groups connected through various linkers (e.g., alkylene groups), or linear or branched polyamines. In some embodiments, the polyamine group has an increased interaction surface area compared to short chain amine-containing compounds due to the increased number of amine groups in the polymeric chain. In some embodiments, the polyamine group is bonded to the substrate 102E through van der Waals interactions, hydrogen bonding, and/or ionic interactions.

    [0120] In some embodiments of any of the functional materials (compounds) herein, the functional portion includes an adsorbing moiety that captures CO.sub.2 (e.g., as in a CO.sub.2 adsorbing moiety). In some embodiments, the CO.sub.2 adsorbing moiety includes one or more amine-containing moieties. In some embodiments, the amine-containing moieties are an aminosilane, an amine, a polyamine, or any combination of these. Additional details regarding CO.sub.2 adsorbing moieties are described herein.

    [0121] As also described herein, in some embodiments the functional portion includes an interaction moiety that interacts with at least a portion of the surface of a substrate. In some embodiments, the interaction moiety is selected based on the substrate to be functionalized. In some embodiments, the substrate to be functionalized includes silica, and the interaction moiety is configured to react with silica. In some embodiments, the interaction moiety comprises a silane moiety that reacts with the surface of the silica substrate. In other embodiments, the substrate to be functionalized includes a metal-organic framework (MOF) material, and the interaction moiety is configured to react with the MOF material. In some embodiments, the interaction moiety comprises a silane moiety that reacts with the surface of the MOF substrate. In other embodiments, the substrate to be functionalized includes a resin material, and the interaction moiety is configured to react with the resin material. In some embodiments, the interaction moiety comprises an amine moiety that reacts with the surface of the resin substrate. The interaction moiety can interact with the substrate surface by way of covalent and/or non-covalent bonding interactions (e.g., as described herein). Additional details regarding interaction moieties and substrates are described herein.

    [0122] Such moieties can be introduced in any useful manner. For instance, such moieties can be present in one or more compounds, which in turn can be provided within a suspension or a mixture (e.g., a functionalization mixture). When a substrate is also present, then the compounds can interact with the substrate to provide a functionalized material. Any useful compound(s) can be employed. In one non-limiting instance, the amine moiety and silane moiety are provided by way of an aminosilane compound, which in turn reacts with or interacts with the substrate surface to provide amine-containing groups. In another non-limiting embodiment, the amine moiety is provided by way of a polyamine compound, which in turn reacts with or interacts with the substrate surface to provide amine-containing groups. In yet another non-limiting instance, both an aminosilane compound and a polyamine compound are employed to provide a functionalized surface. In some embodiments, such reactions result in covalent and/or non-covalent interactions, in which a linking group (e.g., by way of optionally substituted aliphatic, alkylene, alkenylene, alkynylene, heteroaliphatic, heteroalkylene, heteroalkenylene, heteroalkynylene, aromatic, arylene, heteroaromatic, heteroarylene, and the like) is present between a functional group (or a moiety) and the substrate surface. In some embodiments, an amine moiety is an amine functional group itself (e.g., NR.sup.N1R.sup.N2, as described herein) or a portion of a compound including the amine functional group (e.g., -L-NR.sup.N1R.sup.N2, in which L, R.sup.N1, and R.sup.N2 is any described herein). Additional details regarding compounds, suspensions, and mixtures to provide functional portions are described herein.

    [0123] In use, the functionalized material is provided as a layer (e.g., a layer of beads or powder) or a bed over which or through which a gaseous mixture including CO.sub.2 is flowed. Such a material is considered a sorbent or adsorbent, in which these terms are used interchangeably unless otherwise specified. Gas exiting the sorbent has a lower concentration of CO.sub.2 than the entering gas. In some embodiments, the functionalized material reversibly adsorbs CO.sub.2 over a number of cycles, e.g., a number of adsorption and desorption steps, in which a cycle includes at least one adsorption step and at least one desorption step. Higher cycle counts are used to characterize materials having longer product lifetimes when used in CO.sub.2 capture applications. In some non-limiting implementations, the functionalized material reversibly adsorbs CO.sub.2 over 100 cycles (e.g., over 500 cycles, over 1000 cycles, over 2000 cycles, or over 3000 cycles). Here and throughout the specification, reference to a measurable value such as an amount, a temporal duration, and the like, the recitation of the value encompasses the precise value, approximately the value, and within +10% of the value. For example, here 100 cycles include precisely 100 cycles, approximately 100 cycles, and within +10% of 100 cycles.

    [0124] CO.sub.2 adsorbed to the functionalized material may be released (e.g., desorbed) under some conditions. As one example, reducing the gas pressure surrounding the functionalized material desorbs captured CO.sub.2. As another example, reducing the partial pressure of CO.sub.2 surrounding the functionalized material desorbs captured CO.sub.2 (e.g., by purging with N.sub.2 or another gas). In some embodiments, one or more of these approaches facilitates recapture of the adsorbed CO.sub.2 in a secondary environment. In some embodiments, the functionalized material is exposed to a reduced gas pressure of less than 5 psi (e.g., less than 3 psi, 1.5 psi, 1 psi, or 0.1 psi).

    [0125] In some embodiments, increasing the temperature of the functionalized material destabilizes bonding between the amine group and CO.sub.2, thereby desorbing the CO.sub.2 from the functionalized material. In some implementations, the functionalized material desorbs CO.sub.2 at temperatures above 60 C. (e.g., above 60 C., 70 C., 80 C., or 90 C.). In some embodiments, increasing the temperature and decreasing gas pressure concurrently increases the rate at which the CO.sub.2 desorbs from the functionalized material.

    [0126] Indeed, release of gas from a sorbent can include any useful process. In one example, a swing process can be employed. Such swing processes can include application of a change in temperature, of a change in pressure, and/or of a vacuum to release the gas from the sorbent composition. Swing processes can include Temperature Swing Adsorption (TSA), Pressure Swing Adsorption (PSA), and Vacuum Swing Adsorption (VSA), or a combination of these. In some embodiments, the released gas can be provided as outputs, and such outputs can be generated by exposing the sorbent to a temperature swing adsorption process, a pressure swing adsorption, a vacuum swing adsorption process, or a combination of any of these.

    i. Substrate

    [0127] In some embodiments the functionalized material includes any useful substrate. In some embodiments the substrate is in the form of a plurality of porous particles. In some embodiments, the substrate has a porous surface upon which a functional portion is disposed. In some embodiments, the substrate comprises a porous substrate, such as a porous ceramic (e.g., a porous metal oxide, a porous metalloid oxide, or combinations thereof or mixed forms thereof), a porous metal-organic substrate, or a porous polymeric substrate. In some embodiments, the substrate comprises a porous ceramic/metal oxide together with porous silica (e.g., including porous alumina, calcium silicate, sodium aluminosilicate). Yet other non-limiting examples of substrates include porous silica or silicate (e.g., amorphous silica, calcium silicate, sodium aluminosilicate), porous alumina (e.g., including sodium aluminosilicate), metal-organic framework (MOF), or resin (e.g., as described herein). In some embodiments, the substrate is provided in any form (e.g., precipitated, sol-gel, fumed, calcined, agglomerated, or granulated forms, which in turn can be provided as a powder, a granule, and the like). In some embodiments the substrate is sourced from standard industrial sources or is synthesized. In some embodiments, the substrate is water-stable and/or resistant to corrosion and oxidation.

    [0128] The dimension of the substrate can vary based on the application and/or the source. Depending on the shape of the substrate, a dimension of the substrate can include a length, width, height, cross-sectional dimension, circumference, radius (e.g., external or internal radius), diameter, or another metric to indicate a size of the substrate.

    [0129] In some embodiments, the substrate comprises a plurality of porous particles, in which the plurality of porous particles is characterized by a certain effective average particle size and/or by a certain distribution of sizes. For example and without limitation, in some embodiments the plurality of porous particles has an effective average particle size in which at least 50% of the porous particles therein are of a specified size. For example and without limitation, in some embodiments the plurality of porous particles exhibits a distribution of sizes that is from about 25 micrometers (m) to 3 millimeter (mm) or from 25 m to 4 mm. Thus, in some embodiments where the plurality of porous particles exhibits a distribution of sizes, at least 60 percent, at least 70 percent, at least 80 percent, at least 90 percent, at least 95 percent, at least 99 percent, or all of the porous particles have a sieve diameter that is within the upper and lower bounds of the specified distribution.

    [0130] In some embodiments, the plurality of porous particles exhibits a distribution of sieve diameters, with an average sieve diameter that is in a range from 25 m to 4 mm (e.g., from 45 to 800 m, 50 to 500 m, 60 to 300 m, 45 to 150 m, 70 to 80 m, 25 m to 3 mm, 25 m to 2 mm, 25 m to 1 mm, 50 m to 4 mm, 50 m to 3 mm, 50 m to 2 mm, 50 m to 1 mm, 100 m to 4 mm, 100 m to 3 mm, 100 m to 2 mm, 100 m to 1 mm, 200 m to 4 mm, 200 m to 3 mm, 200 m to 2 mm, 200 m to 1 mm, 250 m to 4 mm, 250 m to 3 mm, 250 m to 2 mm, 250 m to 1 mm, 500 m to 4 mm, 500 m to 3 mm, 500 m to 2 mm, 500 m to 1.5 mm, 1 to 2 mm, 1 to 2.5 mm, 1 to 3 mm, or 1 to 4 mm). In some implementations, the average sieve diameter of the plurality of porous particles is less than 500 m (e.g., less than 400 m, less than 350 m, less than 300 m, less than 200 m, or less than 100 m). In some embodiments, the substrate (e.g., porous silica particles) has an average sieve diameter of at least 0.5 mm.

    [0131] In some embodiments, the sieve diameter of the plurality of porous substrate particles is a measure of central tendency determined over the sieve diameter of the plurality of porous particles. As used herein, the term sieve diameter is the smallest mesh size through which a particle can pass. As used herein, the term measure of central tendency refers to a central or representative value for a distribution of values. Non-limiting examples of measures of central tendency include a mean, arithmetic mean, weighted mean, midrange, midhinge, trimean, geometric mean, geometric median, Winsorized mean, median, and mode of the distribution of values. For instance, in some embodiments, the sieve diameter of the plurality of porous particles is an average sieve diameter of the plurality of porous particles used for generating the functionalized crosslinked particles.

    [0132] In some embodiments, the plurality of porous particles comprises a distribution of sieve diameters.

    [0133] In some embodiments, the sieve diameter, or the measure of central tendency (e.g., mean) thereof, for the plurality of porous particles (substrate) is at least 0.2 millimeters (mm), at least 0.3 mm, at least 0.4 mm, at least 0.5 mm, at least 0.6 mm, at least 0.7 mm, at least 1 mm, at least 1.5 mm, at least 2 mm, at least 2.5 mm, at least 3 mm, at least 3.5 mm, at least 4 mm, or at least 5 mm. In some embodiments, the sieve diameter, or the measure of central tendency (e.g., mean) thereof, of the plurality of porous particles is no more than 10 mm, no more than 5 mm, no more than 4 mm, no more than 3.5 mm, no more than 3 mm, no more than 2.5 mm, no more than 2 mm, no more than 1.5 mm, no more than 1 mm, no more than 0.5 mm, or no more than 0.3 mm. In some embodiments, the sieve diameter, or the measure of central tendency (e.g., mean) thereof, for the plurality of porous particles is from 0.2 mm to 1 mm, from 0.5 mm to 2 mm, from 1 mm to 4 mm, from 0.4 mm to 4 mm, from 3 mm to 5 mm, or from 4 mm to 10 mm. In some embodiments, the sieve diameter, or the measure of central tendency (e.g., mean) thereof, for the plurality of porous particles falls within another range starting no lower than 0.2 mm and ending no higher than 10 mm.

    [0134] In some embodiments, the sieve diameter of the porous particles (substrate) varies based on the application and/or the source. In some embodiments, the porous particles (substrate) have an average sieve diameter in the range from 0.25 mm to 4.0 mm (e.g., 0.25 mm to 1.5 mm, 0.5 mm to 1.5 mm, 0.5 mm to 1.0 mm, 1.0 mm to 2.0 mm, 1.5 to 2.0 mm, 0.5 mm to 4.0 mm, 1.0 mm to 4.0 mm, or 2.0 mm to 4.0 mm). In some embodiments, the porous particles have a distribution of sieve diameters having an average (e.g., mean) diameter ranging from 1 mm to 1.2 mm. In some embodiments, the distribution of sieve diameters for the plurality of porous particles comprises sieve diameters of from 0.2 mm to 1 mm, from 0.5 mm to 2 mm, from 1 mm to 4 mm, from 0.4 mm to 4 mm, from 3 mm to 5 mm, from 0.2 mm to 5 mm, from 1 mm to 8 mm, from 0.3 mm to 5 mm, from 0.2 mm to 10 mm, or from 4 mm to 10 mm. In some embodiments, the distribution of sieve diameters for the plurality of porous particles falls within another range starting no lower than 0.2 mm and ending no higher than 10 mm.

    [0135] The width of the distribution around the average can affect adsorption performance of the substrate (e.g., plurality of porous particles). In some non-limiting implementations, the width of the distribution is in a range from 5 to 50 m around the average (e.g., from 10 to 40 m or 20 to 30 m). In some examples, the width of the distribution is in a range from 50 m to 2 mm around the average (e.g., from 75 m to 1.5 mm, 100 m to 1.25 mm, 200 m to 1 mm, 300 to 800 m, 500 m to 2 mm, 500 m to 1.5 mm, 500 m to 1 mm, 1 to 2 mm, 1.2 to 1.8 mm, 1.4 to 2 mm, or 1.5 to 2 mm).

    [0136] In some embodiments, the width of the distribution is alternatively described using D.sub.90, D.sub.50, and/or D.sub.10 values. These values signify a percentage of the total distribution of sizes for material within a sample, up to and including the value. For example, a D90 value of 500 m indicates that 90% of the material (e.g., the plurality of porous particles) within a sample has a size of 500 m or smaller. In some embodiments, the functionalized material (e.g., the plurality of functionalized crosslinked particles) has a D.sub.10 value of 30 m or a D-90 value of 150 m. In some embodiments, the functionalized material has a D.sub.10 value of 100 m or a D90 value of 500 m, a D.sub.10 value of 150 m or a D90 value of 1000 m, a D.sub.10 value of 400 m or a D90 value of 1500 m, a D.sub.10 value of 500 m or a D90 value of 2000 m, or a D10 value of 1000 m or a D90 value of 3000 m. In some embodiments, the functionalized material has a D50 value of 1000 m, 1100 m, 1200 m, 1300 m, 1400 m, or 1500 m.

    [0137] In general and without wishing to be bound by theory, a smaller particle size with high porosity or high pore volume and BET surface area can facilitate better functionalized material synthesis results, which in turn can enable higher CO.sub.2 capture capacity due to relatively higher surface area leading to higher amine coating concentrations. Such types of smaller particles could permit faster adsorption inside of the particle as the gas diffusion path may be shorter. If gas diffusion to the particle surface rate is not limited, then a smaller particle size may be beneficial to gas adsorption. Smaller particle size (e.g., having a small average diameter, radius, or width) could reduce the adsorption process energy cost for a fluidization process.

    [0138] Yet other particle effects for smaller particle sizes can include smaller interparticle volume, slower interparticle gas kinetics (e.g., due to longer interparticle diffusion length), faster intraparticle gas kinetics (e.g., due to shorter intraparticle diffusion length), higher packed bed back pressure, higher packing density, and/or higher external surface area. Particle effects for larger particle sizes can include larger interparticle volume, faster interparticle gas kinetics (e.g., due to shorter interparticle diffusion length), slower intraparticle gas kinetics (e.g., due to longer intraparticle diffusion length), lower packed bed back pressure, lower packing density, and/or lower external surface area. A skilled artisan could adapt such sizes and effects to provide a certain adsorbent for particular uses.

    [0139] In some embodiments the substrate (e.g., plurality of porous particles) is characterized by the presence of one or more pores. As seen in FIG. 1A, pores 104 can be considered openings that extend from the exterior surface of the substrate into the interior of the particles. In some embodiments, the presence of such pores increase the surface area of the substrate. Pore dimension varies from pore to pore, and can vary within an individual pore, see, e.g., pores 104A-a, 104A-b. Furthermore, depending on pore shape, a pore dimension can be a length, width, height, cross-sectional dimension, circumference, radius (e.g., external or internal radius), diameter, or another metric to indicate pore size.

    [0140] In some embodiments, the pore size of the pores is in a range from 60 angstroms () to 700 angstroms () (e.g., from 60 to 400 , 60 to 300 , 80 to 300 , 100 to 700 , 100 to 500 , 100 to 200 , 150 to 250 , 200 to 700 , 300 to 700 , 300 to 500 , or 500 to 700 ). In some embodiments, the pore have an average pore size or a mane pore size that is from about 60 100 to about 400 . In some implementations, the dimension (e.g., a diameter, cross-sectional length, etc.) of the pore(s) is greater than 90 (e.g., greater than 100 , 120 , or 150 ). Without wishing to be limited by theory, a larger diameter of the pore could increase adsorption and desorption rates and could facilitate higher filling of the pores with amine moieties without pore-clogging, which in turn could reduce adsorption and desorption efficiency.

    [0141] In some embodiments, the substrate is characterized by a porosity of 1 to 200 nm and/or an average pore size of 30 to 80 nm. In some embodiments, a dimension (e.g., a diameter, a cross-sectional length, etc.) of the pore(s) is in a range from 1 to 200 nm (e.g., 1 to 180 nm, 1 to 160 nm, 1 to 120 nm, 1 to 100 nm, 1 to 70 nm, 1 to 30 nm, 1 to 20 nm, 10 to 200 nm, 10 to 180 nm, 10 to 160 nm, 10 to 120 nm, 10 to 100 nm, 10 to 70 nm, 10 to 50 nm, 30 to 200 nm, 30 to 180 nm, 30 to 160 nm, 30 to 120 nm, 30 to 100 nm, 30 to 90 nm, 30 to 70 nm, 70 to 200 nm, 70 to 180 nm, 70 to 160 nm, or 70 to 120 nm). In some embodiments, an average dimension (e.g., an average diameter) of the pore(s) is in a range from 30 to 80 nm, 20 to 100 nm, or 20 to 70 nm).

    [0142] In some embodiments, the substrate (e.g., the plurality of porous particles) is characterized by a plurality of pores of different sizes. For example and without limitation, smaller pores in the range of 1 to 30 nm can contribute to relatively higher surface areas, which can allow for more surface anchoring with amine moieties to improve stability of the coating or surface functionalization layer. Larger pores in the range of 30 to 90 nm can contribute to relatively larger pore volumes that allow for larger volumes of active amine moieties to be contained within the pores to improve the CO.sub.2 uptake. The largest pores in the range of 70 to 200 nm can provide open channels that contribute to relatively higher gas diffusion rates for improved CO.sub.2 adsorption kinetics. Without wishing to be limited by mechanism, a substrate (e.g., a silica substrate) that possesses significant porosity in these three ranges may be employed as substrates for amine-coated sorbents. In some non-limiting embodiments, a substrate having reduced porosity in one or two of these ranges may suffer from relatively decreased performance in the corresponding function but may still function as substrates for amine-coated sorbents.

    [0143] In some embodiments, a substrate (e.g., plurality of porous particles) is characterized by a plurality of pores, where each pore is characterized by a pore dimension, where at least one pore dimension is in a first range of about 1 to 30 nm, a second range of about 30 to 90 nm, and/or a third range of about 70 to 200 nm. Such ranges can be any other ranges of pore dimensions described herein.

    [0144] Pores can have any useful shape (e.g., cylindrical, spherical, tubular, and the like), configuration, distribution, and arrangement (e.g., hexagonal, cubic, and the like). In some embodiments, the pores have an irregularly round cross-sectional shape, or a hexagonal cross-sectional shape, though this is not limiting. Pores may also be characterized by pore size distributions, which can be determined in any useful manner (e.g., using mercury, nitrogen, argon, helium, etc. in porosimetry or using Brunauer-Emmett-Teller (BET) analysis with appropriate methods such as the Barrett Joyner Halenda (BJH) or Non-Local Density Functional Theory (NLDFT) models).

    [0145] Pore size distribution profiles can include those for non-limiting sorbents with only narrow pores having high surface areas but relatively lower pore volumes and gas kinetics, non-limiting sorbents with only moderately sized pores having high pore volumes and moderate surface areas and gas kinetics, non-limiting sorbents with only large pores having fast gas kinetics and high pore volumes but relatively lower surface areas, and non-limiting sorbents with pores in a plurality of ranges having high surface areas, pore volumes, and channels for gas diffusion allowing for stable surface coating, relatively higher concentrations of active amines, and fast gas kinetics.

    [0146] The pores can have any useful configuration. In some embodiments, pores may be provided on a surface of the substrate. Such pores may or may not be interconnected. For example and without limitation, pores could extend into the central volume of the substrate and form interconnected channels. Without wishing to be limited by theory, the pores can create a volume within the substrate in which gases may flow for enhanced capture of such gases. Furthermore, such pores may create additional (e.g., and accessible) surface area for functionalization.

    [0147] In some embodiments, pores are characterized by pore volume, total surface area, accessible surface area, porosity, and the like. In some embodiments, the volume of the pores is greater than 0.1 mL/g, (e.g., greater than 0.5 mL/g, greater than 0.8 mL/g, greater than 1 mL/g, greater than 1.2 mL/g, greater than 1.5 mL/g, or greater than 1.8 mL/g). In some embodiments, the volume of the pores is from 0.1 to 5 mL/g (e.g., from 0.1 to 4.5 mL/g, 0.1 to 4 mL/g, 0.1 to 3 mL/g, 0.1 to 3.5 mL/g, 0.1 to 3 mL/g, 0.1 to 2.5 mL/g, 0.1 to 2 mL/g, 0.1 to 1.5 mL/g, 0.1 to 1.2 mL/g, 0.1 to 1 mL/g, 0.5 to 5 mL/g, 0.5 to 4.5 mL/g, 0.5 to 4 mL/g, 0.5 to 3.5 mL/g, 0.5 to 3 mL/g, 0.5 to 2.5 mL/g, 0.5 to 2 mL/g, 0.5 to 1.5 mL/g, 0.5 to 1 mL/g, 1 to 5 mL/g, 1 to 4.5 mL/g, 1 to 4 mL/g, 1 to 3.5 mL/g, 1 to 3 mL/g, 1 to 2.5 mL/g, 1 to 2 mL/g, 1.5 to 5 mL/g, 1.5 to 4.5 mL/g, 2.5 to 5 mL/g, 2.5 to 4.5 mL/g, 3.5 to 5 mL/g, 3.5 to 4.5 mL/g, 1.5 to 3.5 mL/g, 1 to 3 mL/g, 1 to 1.5 mL/g, 1 to 1.2 mL/g, or 1.5 to 2.5 mL/g). Without wishing to be limited theory, increased total volume of the pores could allow more amine moieties to be grafted or into the pores and, thus increase the adsorption potential of the functionalized material.

    [0148] Total surface area can be used to characterize the substrate. The total surface area of the substrate includes the surface area of not only the outer surface but also the surface area within the pores. In some embodiments, the total surface area is greater than 100 m.sup.2 per dry gram (m.sup.2/g) of substrate. In some implementations, the total surface area is greater than 300 m.sup.2/g (e.g., greater than 200 m.sup.2/g, 400 m.sup.2/g, 500 m.sup.2/g, or 800 m.sup.2/g). In some implementations, the total surface area is greater than 1200 m.sup.2/g (e.g., greater than 200 m.sup.2/g, 400 m.sup.2/g, 500 m.sup.2/g, or 800 m.sup.2/g). In some implementations, the total surface area is greater than 2000 m.sup.2/g (e.g., greater than 2500 m.sup.2/g, 3000 m.sup.2/g, 4000 m.sup.2/g, 5000 m.sup.2/g, or 6000 m.sup.2/g). In some examples, the total surface area is in a range from 100 to 1200 m.sup.2/g (e.g., from 200 to 1200 m.sup.2/g, 400 to 1200 m.sup.2/g, 500 to 1200 m.sup.2/g, 700 to 1200 m.sup.2/g, 800 to 1200 m.sup.2/g, 1000 to 1200 m.sup.2/g, 100 to 1000 m.sup.2/g, 100 to 800 m.sup.2/g, 100 to 500 m.sup.2/g, 100 to 400 m.sup.2/g, 100 to 900 m.sup.2/g, 200 to 900 m.sup.2/g, 400 to 900 m.sup.2/g, 500 to 1000 m.sup.2/g, or 500 to 800 m.sup.2/g). In some examples, the total surface area is in a range from 1000 to 12000 m.sup.2/g (e.g., from 1000 to 11000 m.sup.2/g, 1000 to 10000 m.sup.2/g, 1000 to 9000 m.sup.2/g, 1000 to 8000 m.sup.2/g, 1000 to 7000 m.sup.2/g, 1000 to 6000 m.sup.2/g, 1000 to 5000 m.sup.2/g, 1000 to 4000 m.sup.2/g, 2000 to 12000 m.sup.2/g, 2000 to 11000 m.sup.2/g, 2000 to 10000 m.sup.2/g, 2000 to 9000 m.sup.2/g, 2000 to 8000 m.sup.2/g, 2000 to 7000 m.sup.2/g, 2000 to 6000 m.sup.2/g, 2000 to 5000 m.sup.2/g, 2000 to 4000 m.sup.2/g, 3000 to 12000 m.sup.2/g, 3000 to 11000 m.sup.2/g, 3000 to 10000 m.sup.2/g, 3000 to 9000 m.sup.2/g, 3000 to 8000 m.sup.2/g, 3000 to 7000 m.sup.2/g, 3000 to 6000 m.sup.2/g, 3000 to 5000 m.sup.2/g, 3000 to 4000 m.sup.2/g, 4000 to 12000 m.sup.2/g, 4000 to 11000 m.sup.2/g, 4000 to 10000 m.sup.2/g, 4000 to 9000 m.sup.2/g, 4000 to 8000 m.sup.2/g, 4000 to 7000 m.sup.2/g, 4000 to 6000 m.sup.2/g, or 4000 to 5000 m.sup.2/g). In some examples, the total surface area is in a range from 100 to 12000 m.sup.2/g (e.g., including ranges therebetween, such as any described herein).

    [0149] Without wishing to be limited by theory, higher total surface area could increase the available area for functionalization (e.g., by way of interactions between a silane moiety and a surface of the substrate) and/or increase the adsorption potential of the functionalized material. Surface area can be determined in any useful manner, e.g., by using the BET model or other methodologies described herein.

    [0150] Any useful combination of features may be present in a substrate. In some embodiments, the substrate comprises a greatest dimension (e.g., an average greatest dimension) of at least 70 m and a plurality of pores, where the plurality of pores is characterized by a volume that is greater than 0.8 mL/g and by a size (e.g., an average size) of at least 90 . In some embodiments, the substrate comprises a greatest dimension (e.g., an average greatest dimension) in a range from 0.5 to 2 mm and a plurality of pores, where the plurality of pores is characterized by a volume greater than 0.5 ml/g and a size in a range from 20 to 1000 . Other combinations of features are possible.

    a. Silica

    [0151] In some embodiments, the substrate comprises silica (e.g., silicon dioxide). Any methods or compounds herein can be used to functionalize a silica substrate to provide a functionalized silica. For example and without limitation, in some embodiments the functionalized silica has amine moieties that are bound to the silica surface (e.g., by way of siloxane bonds, other covalent bonds, or even non-covalent bonds).

    [0152] In some embodiments the silica is in any useful form, such as beads (e.g., microbeads, nanobeads, or combinations thereof), powders (e.g., micropowders, nanopowders, or combinations thereof; or from micrometer size to millimeter size), particles (e.g., microparticles, nanoparticles, or combinations thereof), and the like. Furthermore, in some embodiments the silica includes any useful type, such as amorphous or non-crystalline silica (e.g., precipitated, sol-gel, fumed, calcined, agglomerated, or other forms of silica) or silicates (e.g., calcium silicate, sodium aluminosilicate, and the like). In some embodiments, the silica includes one or more pores (e.g., as in porous silica). Furthermore, within such a substrate, pores can have any useful shape, configuration, distribution, and arrangement (e.g., hexagonal arrangement of pores in MCM-41, which in turn can be spherical or any other shape). In some embodiments, the substrate can be bead-shaped, though this is not limiting. Silica can be obtained or provided in any useful manner, such as by employing synthetic methods or by sourcing from standard industrial sources.

    [0153] In some non-limiting embodiments, the substrate 102A, 102B, 102C is a silica substrate. In some non-limiting embodiments, the substrate 102A, 102B, 102C is composed of amorphous silica, e.g., non-crystalline silica.

    b. Metal-Organic Framework (MOF)

    [0154] Metal organic frameworks (MOFs) are a class of compounds including metal ions or clusters coordinated to organic ligands to form one-, two-, or three-dimensional structures (e.g., porous three-dimensional structures). Various kinds of MOF are synthesized with different combinations of metal ions and organic ligands (e.g., as described herein) and all such MOFs are within the scope of the present disclosure. In some embodiments, MOF substrates are used as a porous structure for functionalization to achieve carbon capture.

    [0155] In some embodiments, the substrate comprises a MOF. Any methods or compounds herein are used to functionalize a MOF substrate to provide a functionalized MOF. Without wishing to be limited by theory, a functionalized MOF features surface areas larger than alternative substrates (e.g., zeolite, silica, etc.) for increased functionalization (e.g., >2000 m.sup.2/g). For example and without limitation, in some embodiments a functionalized MOF features amine moieties that are bound to hydroxy functional side groups present on the surface, thereby allowing for CO.sub.2 uptake. The amine moiety is provided by any compound described herein (e.g., an aminosilane compound) for increased carbon capture (e.g., >2 mol CO.sub.2/kg).

    [0156] In some embodiments MOFs are provided in any useful manner. In some embodiments, MOFs are produced using reactor-based, solvothermal (e.g., hydrothermal) synthesis methods in which a metal source (e.g., a metallic substrate or a metal-containing salt), an organic ligand, and an optional competing agent/additive are reacted together to produce MOF crystals of 10 m to 1 mm in size (e.g., in diameter), including ranges therebetween (e.g., from 10 to 500 m, 10 to 300 m, 50 to 300 m, or 50 to 100 m in size). In some embodiments, the crystals are extruded, pelletized, and functionalized with adsorbing moieties to provide a functional group disposed on a surface of the MOF, thereby providing a functionalized MOF.

    [0157] In some embodiments, MOFs are synthesized by providing a metal source and an organic ligand. Under certain conditions, metal-containing centers form nodes, and organic ligands form bridges between the nodes to provide self-assembled, networked structures. By selecting certain metals and ligands with certain reaction conditions, various structural characteristics (e.g., topology, pore structure, pore size, and the like) of the MOF material are controlled in some embodiments.

    [0158] Any useful metal source can be employed. Non-limiting examples include metal sources comprising aluminum (Al), chromium (Cr), copper (Cu), iron (Fe), titanium (Ti), vanadium (V), zinc (Zn), zirconium (Zr), as well as salts thereof (e.g., halide salts, nitrate salts, or others described herein), combinations thereof, and mixtures thereof. In some embodiments, the metal source is an aluminum-based metal source, an iron-based metal source, a titanium-based metal source, a zinc-based metal source, or a zirconium-based metal source. In some embodiments, the metal ions selected for the MOF substrate include an economical, commercially available, cost-effective metal ion source, such as aluminum (Al), iron (Fe), titanium (Ti), zinc (Zn) (e.g., zinc nitrate (ZnNO.sup.3)), zirconium (Zr) (e.g., zirconium tetrachloride (ZrCl.sup.4)).

    [0159] Any useful organic ligand is employed in some embodiments. Non-limiting ligands include, e.g., 3,3,5,5-azobenzenetetracarboxylate (ABTC.sub.4); 1,4-benzenedicarboxylate (BDC.sub.2); (X)BDC.sub.2 or (X).sub.2BDC.sub.2, where each X is, independently, alkyl, halo, hydroxy, nitro, amino, carboxyl, alkoxy, cycloalkoxy, aryloxy, or benzyloxy (e.g., 2-amino-1,4-benzenedicarboxylate (NH.sub.2BDC.sub.2), 2-hydroxy-1,4-benzenedicarboxylate (OHBDC.sub.2), 2,5-diamino-1,4-benzenedicarboxylate ((NH.sub.2).sub.2BDC.sub.2), 2,5-dihydroxy-1,4-benzenedicarboxylate ((OH).sub.2BDC.sub.2 or DHBDC.sub.2), 2,3-dihydroxy-1,4-benzenedicarboxylate, or 2,6-dihydroxy-1,4-benzenedicarboxylate); 1,1-biphenyl-4,4-dicarboxylate (BPDC.sub.2); (X)BPDC.sub.2 or (X).sub.2BPDC.sub.2, where each X is, independently, alkyl, halo, hydroxy, nitro, amino, carboxyl, alkoxy, cycloalkoxy, aryloxy, or benzyloxy (e.g., 2-amino-1,1-biphenyl-4,4-dicarboxylate (NH.sub.2BPDC.sub.2), 2-hydroxy-1,1-biphenyl-4,4-dicarboxylate (OHBPDC.sub.2), 2,2-diamino-1,1-biphenyl-4,4-dicarboxylate ((NH.sub.2).sub.2BPDC.sub.2), or 2,2-dihydroxy-1,1-biphenyl-4,4-dicarboxylate ((OH).sub.2BPDC.sub.2)); 1,3,5-benzenetricarboxylate or 1,2,4-benzenetricarboxylate (BTC.sub.3); 2,5-dihydroxy-1,4-benzenedicarboxylate (DHBDC.sub.2); 2,5-dioxido-1,4-benzenedicarboxylate (DOBDC.sub.4); 4,4,4-s-triazine-2,4,6-triyl-tribenzoate (TATB.sub.3); 1,3,6,8-tetrakis(p-benzoate) pyrene (TBAPy.sub.4-); 1,1-triphenyl-4,4-dicarboxylate (TPDC.sub.2); and (X).sub.2-TPDC.sub.2 or (X).sub.4-TPDC.sub.2, where each X is, independently, alkyl, halo, hydroxy, nitro, amino, carboxyl, alkoxy, cycloalkoxy, aryloxy, or benzyloxy (e.g., 2,2-dihydroxy-1,1-triphenyl-4,4-dicarboxylate (di-OH-TPDC) or 2,2, 6,6-tetrahydroxy-1,1-triphenyl-4,4-dicarboxylate (tetra-OH-TPDC)). In some embodiments, such ligands are provided as a compound in its protonated form to the metal source. In some embodiments, the ligand optionally includes one or more counterions (e.g., one or more counteranions or countercations), as well as a cation thereof, an anion thereof, a protonated form thereof, a salt thereof, or an ester thereof.

    [0160] In some embodiments, the ligand includes hydroxy functional side groups. Without wishing to be limited by theory or mechanism, the presence of hydroxy functional side groups may facilitate post-synthetic functionalization of the MOF surface with adsorbing moieties (e.g., amine moieties).

    [0161] In some embodiments, the hydroxy reacts with a silane moiety of an aminosilane compound to covalently bond the silane moiety to the hydroxy group of the organic ligand, while increasing the density of amine moieties on a surface of the MOF substrate, thereby increasing the CO.sub.2 capture capacity of the MOF substrate. Non-limiting examples of aminosilanes suitable for bonding with the MOF substrate for carbon capture include methoxysilanes, chlorosilanes, ethoxysilanes, as well as others described herein.

    [0162] In some embodiments, the organic ligand is provided by a compound that is 1,4-di-(4-carboxy-2,6-dihydroxyphenyl)benzene. Within the MOF, this compound provide sa 2,2,6,6-tetrahydroxy-1,1-triphenyl-4,4-dicarboxylate (tetra-OH-TPDC) ligand. In some embodiments, this compound is employed with a metal source that includes Zn(NO.sub.3).sub.2.Math.6H.sub.2O.

    [0163] In some embodiments, the organic ligand is 2-hydroxyterephthalic acid (e.g., to provide a 2-hydroxy-BDC ligand), 2,5-dihydroxyterephthalic acid (e.g., to provide a 2,5-dihydroxy-BDC ligand), 2,3-dihydroxyterephthalic acid (e.g., to provide a 2,3-dihydroxy-BDC ligand), 2,6-dihydroxyterephthalic acid (e.g., to provide a 2,6-dihydroxy-BDC ligand), or 2-boronobenzene-1,4-dicarboxylic acid (e.g., to provide a 2-borono-BDC ligand).

    [0164] Any useful MOF can be employed. Non-limiting examples of MOF include, e.g., HCC-1[Zn.sub.4O(di-OH-TPDC).sub.3]; HCC-2 [Zn.sub.4O(tetra-OH-TPDC).sub.3], HKUST-1 [Cu.sub.3 (BTC).sub.2 or Cu.sub.3 (BTC).sub.3 (H.sub.2O).sub.3], IRMOF-1 or MOF-5 [Zn4.sub.O(BDC).sub.3], IRMOF-3 [Zn.sub.4O(NH.sub.2-BDC).sub.3], IRMOF-10 [Zn.sub.4O(BPDC).sub.3], IRMOF-16 [Zn.sub.4O(TPDC).sub.3], MIL-47 [VO(BDC)], MIL-101-Cr [Cr.sub.3O(BDC).sub.3(H.sub.2O).sub.2F or Cr.sub.3O(BDC).sub.3 (H.sub.2O).sub.3], MIL-101-Fe [Fe.sub.3O(BDC).sub.3 (H.sub.2O).sub.2X or Fe.sub.3O(BDC).sub.3X, where X is a monoanion, such as OH.sup.- or Cl.sup.-], NH.sub.2-MIL-101-Fe [Fe.sub.3O(NH.sub.2-BDC).sub.3 (H.sub.2O).sub.2X or Fe.sub.3O(NH.sub.2-BDC).sub.3X, where X is a monoanion, such as OH.sup.- or Cl.sup.-], NH.sub.2-MIL-101-Al[Al.sub.3O(NH.sub.2-BDC).sub.6X.sub.3 or Al.sub.3O(NH.sub.2-BDC).sub.3 (H.sub.2O).sub.2X, where X is a monoanion, such as OH.sup.- or Cl.sup.-], MIL-125 [Ti.sub.8O.sub.8(OH).sub.4 (BDC).sub.6], NH.sub.2-MIL-125 [Ti.sub.8O.sub.8(OH).sub.4(NH.sub.2-BDC).sub.6], MOF-2 [Zn.sub.2 (BDC).sub.2], MOF-74 [Zn.sub.2 (DHBDC)], MOF-808 [Zr.sub.6O.sub.4 (.sub.3OH).sub.4(OH).sub.6(H.sub.2O).sub.6(BTC).sub.2], NU-1000 [Zr.sub.6(3-O).sub.4(.sub.3OH).sub.4(OH).sub.4(H.sub.2O).sub.4(TBAPy).sub.2], PCN-250 [Fe.sub.3O(ABTC).sub.6 or (Fe.sub.3O).sub.2 (ABTC).sub.3 or (Fe.sub.3O).sub.2 (ABTC).sub.3(OH).sub.2 (H.sub.2O).sub.4], PCN-777 [Zr.sub.6O.sub.4 (.sub.3OH).sub.4(TATB).sub.2 (OH).sub.6(H.sub.2O).sub.6 or Zr.sub.3O.sub.4(OH) (TATB) (H.sub.2O).sub.6], UiO-66 [Zr.sub.6 (O).sub.4(OH).sub.4(BDC).sub.12], UiO-66[Zr.sub.6O.sub.4 (OH).sub.4(BDC).sub.6], UiO-66-DOBDC[Zr.sub.6O.sub.4 (OH).sub.4(DOBC).sub.6], UiO-66-NH.sub.2[Zr.sub.6O.sub.4 (OH).sub.4(NH.sub.2-BDC).sub.6], UiO-66-OH [Zr.sub.6O.sub.4 (OH).sub.4(OH.sup.-BDC).sub.6], or UiO-67 [Zr.sub.6O.sub.4 (OH).sub.4(BPDC).sub.6]. In some embodiments, any of these is modified to include one or more hydroxy groups or additional hydroxy groups (e.g., if a hydroxy group is already present). In some embodiments, the hydroxy group is provided on the organic ligand.

    [0165] In some embodiments, MOFs are provided in any useful form, e.g., particles, crystals, powders, and the like. In some embodiments, the MOF particles include MIL-101-Fe, MIL-101-A1, MIL-125-Ti, PCN-250, UiO-66, UiO-67, or any combination or mixture thereof. In some embodiments, the MOF particles are water-stable.

    [0166] In some embodiments MOF substrates are processed under a variety of synthetic conditions to yield different pore sizes and porosities. In some embodiments, the MOF substrate is a mesoporous or a macroporous MOF material. In general and without wishing to be bound by theory, higher pore opening size facilitate increased surface area, increasing the number of exposed active sites on which post-synthetic modification can occur. Increased exposed active sites facilitates higher concentrations of the adsorbing moiety on the MOF substrate, which in turn enables higher CO.sub.2 capture capacity in some embodiments.

    [0167] In some embodiments, the MOF substrate includes pores, which are openings that extend into the interior volume of the MOF substrate. The pores increase the surface area of the MOF substrate. The dimensions of the pores vary, and can vary within an individual pore. Mesoporous and macroporous MOF materials allow for a large volume of adsorbing moieties (e.g., amines moieties) to be incorporated into the porous matrix. In some embodiments, a mesoporous material includes pores having a greatest opening dimension (e.g., a diameter) in a range from 2 nanometers (nm) and 50 nm, and a macroporous material includes pores having a greatest opening dimension greater than 50 nm. In some embodiments, for a MOF substrate, pore dimension, pore volume, and/or total surface area are any described herein (e.g., a pore dimension from a range from 30 to 400 or greater than 90 ; a pore volume from 0.5 to 5 mL/g; and/or a total surface area greater than 100 m.sup.2/g).

    [0168] In some embodiments the MOF substrate is functionalized to provide a functional portion having an adsorbing moiety. In some embodiments, the adsorbing moiety is an amine moiety (e.g., a primary, secondary, or tertiary amine group, as described herein). In some embodiments, the amine moieties bind to the surface of the MOF from which the hydroxy functional side groups extend. In this example, the interaction moiety includes any that reacts with hydroxy groups present on the surface of the MOF. Non-limiting interaction moieties can be, e.g., a silane moiety (e.g., any described herein). By forming interactions between the interaction moiety and the surface, amine bonding stability and/or lifetime of the sorbent is improved in some embodiments. The functionalization methods herein can be applicable to all form factors of the MOF substrates.

    [0169] In some embodiments, an aminosilane is on the MOF surface. In some embodiments, this aminosilane includes a silane moiety (e.g., a trimethoxysilane moiety, a triethoxysilane moiety, a dimethoxyethoxysilane moiety, a diethoxymethoxysilane moiety, and the like) and an amine moiety. In some embodiments, the aminosilane includes one, two, or three amine moieties (e.g., any described herein for R.sup.A). In some embodiments, the aminosilane has a structure having formula [R.sup.A].sub.3SiX, where each R.sup.A is, independently, an amine moiety comprising at least one amine group (e.g., any described herein) and X is a side group, a reactive group, or a leaving group (e.g., any described herein). In some embodiments, the aminosilane includes a structure having formula [R.sup.N1R.sup.N2N].sub.3SiX, where each of R.sup.N1 and R.sup.N2 is, independently, any described herein (e.g., optionally substituted aliphatic, alkyl, aromatic, or aryl); and X is a side group, a reactive group, or a leaving group (e.g., any described herein, such as halo, hydroxy, and the like). In some embodiments, the aminosilane is or includes tris(ethylmethylamino) chlorosilane. Other examples of aminosilanes include any described herein (e.g., an aminosilane including a structure having formula I).

    [0170] In some embodiments, the aminosilane is on the surface of the MOF, where the aminosilane interacts with a hydroxy group present on an organic ligand within the MOF. In some embodiments, the organic ligand interacts with (e.g., binds to) the metal center within the MOF, and the hydroxy group is unbound from the metal center. In particular embodiments, the silane moiety of the aminosilane interacts with (e.g., binds to or/reacts with) the hydroxy group present on the organic ligand.

    [0171] In some non-limiting embodiments, the substrate 102A, 102B, 102C is a MOF substrate, and the pores 104A-a,b, 104B-a,b, 104C-a,b, represent pores provide by the MOF structure. In some non-limiting embodiments, the substrate 102A, 102B, 102C is composed of crystalline, nanoporous MOF.

    c. Resin

    [0172] Ion-exchange resins generally possess a porous structure that can provide a large surface area for the exchange of ionic compounds. In some embodiments, to provide a functionalized resin, functional portion-containing compounds are adsorbed within the pores and interact with reactive moieties present within such pores. Such interactions include ionic bonding interactions, hydrogen bonding interactions, and/or van der Waals force interactions, and the like. In some embodiments, this process is conducted with multiple types of ion-exchange resin having various types of reactive sites, such as polystyrene sulfonate (e.g., in which the sulfonic acid in the ion-exchange resin includes an acidic reactive site that forms ionic bonds with various amines through ionic bonding). In some embodiments, resin substrates are used as a porous structure for functionalization to achieve carbon capture. In particular embodiments, reactive sites present in the resin are employed during functionalization.

    [0173] In some embodiments, the substrate comprises a resin (e.g., an ion-exchange resin). Any methods or compounds herein are used to functionalize a resin substrate to provide a functionalized resin. For example and without limitation, in some embodiments a functionalized resin features amine moieties that are bound to acidic reactive sites present on the surface, thereby allowing for CO.sub.2 uptake. In some embodiments the amine moiety is provided by any compound described herein (e.g., a polyamine) for increased carbon capture (e.g., >1 mol CO.sub.2/kg or from 1 to 3 mol CO.sub.2/kg).

    [0174] In some embodiments, the substrate comprises an ion-exchange resin (e.g., ion-exchange resin particles). In some embodiments, the ion-exchange resin is sufficiently cross-linked to retain porosity sufficient to facilitate gas diffusion and adsorption when dry.

    [0175] In general, a resin substrate is a portion of an ion-exchange resin that is sourced from standard industrial sources. Non-limiting types of ion-exchange resins include a weak base functionalized resin, an acid functionalized resin such as those with carboxylic or sulfonic acid groups, and a neutral resin with no chemical functionalization.

    [0176] In these types, different molecular interactions are used to retain the introduced amine moieties. In weak base resins, amine moieties are present in the resin and serve as reactive sites. In turn, these reactive sites interact (e.g., by way of hydrogen bonding) with adsorbing moieties that are introduced during functionalization (e.g., by introducing a polyamine, a monoamine, an aminosilane, and the like). In acidic resins, acidic moieties are present as reactive sites in the resin. In some embodiments, introduction of an amine (e.g., a polyamine, a monoamine, an aminosilane, etc.) to this resin results in acid-base reactions, which can form ionic bonds between the reactive sites and the amine. In neutral resins, van der Waals forces and entrapment of larger amines within resin pores are the primary interactions. Without wishing to be limited by theory, in some embodiments ionic bonding interactions with an acidic resin provides the highest bonding strength, relative to the other bonding modes; hydrogen bonding with a weak base rein has less strength than the ionic bonding; and van der Waals forces with neutral resins have the lowest bonding strength, relative to the other two bonding modes.

    [0177] Ion-exchange resins are a class of porous polymers that includes polystyrene (e.g., optionally crosslinked with divinylbenzene), polyacrylate, polymethacrylate (e.g., optionally crosslinked with divinylbenzene), polyphenols/phenol-aldehyde resins (e.g., phenol-formaldehyde), melamine resins, agarose, cellulose, polyacrylamides, polycarbohydrates (e.g., dextrans), polyolefins, or similar resins and thermosets, as well as crosslinked forms of any of these or copolymers of any of these.

    [0178] In some embodiments, resins include ionizable, chelating, ionic, acidic, or basic functional groups, which can interact with ions. In some embodiments, these functional groups include, but are not limited to, carboxylic acids, phosphonic acids, sulfonic acids, sulfoalkyl acids, thiols, iminodiacetic acid, thiourea, aminophosphonic acids, pyridines, phenols, picolylamines, primary amines, secondary amines, tertiary amines, quaternary amines, and alcohol amines.

    [0179] Any useful resin is employed in some embodiments. Non-limiting examples of resin include a base-functionalized resin, an acid-functionalized resin, or a neutral resin including no chemical functionalization. In some embodiments, the acid-functionalized resin include carboxylic and/or sulfonic acid groups. In some embodiments, the resin is a porous polystyrene, polyacrylamide, or phenol-formaldehyde resin that retains its porosity when dry combined with a molecular alkyl amine. Non-limiting examples of porous ion-exchange resins include, but are not limited to, PUROLITE A110 (polystyrenic macroporous, weak base anion resin, free base form, having a primary amine as a functional group), PUROLITE A105 (polystyrenic macroporous, weak base anion resin, free base form, having a tertiary amine as a functional group), PUROLITE C145H (polystyrenic macroporous, strong acid cation resin, hydrogen form, having sulfonic acid as a functional group), PUROLITE C160H (polystyrenic macroporous, strong acid cation resin, hydrogen form, having sulfonic acid as a functional group), PUROLITE MACRONET MN.sup.502 (hyper-crosslinked polystyrenic macroporous, adsorbent resin, strong acid functionality, hydrogen form, having sulfonic acid as a functional group), PUROLITE C104Plus (polyacrylic porous, weak acid cation resin, hydrogen form, having carboxylic acid as a functional group), PUROSORB PAD900 (polydivinylbenzene macroporous, adsorbent resin, non-ionic form), AMBERLITE IRA-402 (strongly basic anion exchanger, C1-form, having quaternary ammonium as a functional group), or DOWEX 50W-X8 (strongly acidic cation exchanger, H.sup.+form, having sulfonic acid as a functional group). Resins can be provided in any useful form, e.g., beads, granules, powders, membranes, fibers, particles, crystals, and the like.

    [0180] In some embodiments, resins are sufficiently porous to facilitate diffusion of gaseous ions into and out of the polymeric matrices. Some resins are highly crosslinked and rigid and retain porosity in a dry state (e.g., a hydration of <15% (wt/wt) of water). The term (wt/wt) is in reference to a ratio of the weight (wt) of a first component to the weight of a second component. For example, 1 gram of a first substance and 10 grams of a second substance defines a 10% (wt/wt) ratio of the first substance to the second substance.

    [0181] In some embodiments, the resin substrate is porous in the dry state. Without wishing to be limited by mechanism, such substrates can facilitate diffusion of gas containing CO.sub.2 into the polymeric matrix for CO.sub.2 capture. Ion-exchange resins can be polymerized under a variety of synthetic conditions to yield different pore sizes and porosities. Larger meso- and macro-pores can allow for a large volume of adsorbing groups to be incorporated into the porous matrices. In some embodiments, a mesoporous resin includes pores having a greatest opening dimension (e.g., diameter) in a range from 2 to 50 nm; and a macroporous resin includes pores having a greatest opening dimension greater than 50 nm.

    [0182] In general and without wishing to be bound by theory, proper pore size (e.g., as in a sorbent with pores in any range herein) can be characterized by high surface areas, pore volumes, and channels for gas diffusion that allows for a stable coating or surface functionalization layer, relatively higher concentrations of adsorbing moieties (e.g., active amines), and/or fast gas kinetics. This, in turn, could enable higher CO.sub.2 capture capacity. In some embodiments, higher porosity can reduce the adsorption process energy cost for a fluidization process.

    [0183] In some embodiments, the resin substrate includes pores, which are openings that extend into the interior volume of the resin substrate. In some embodiments, the pores increase the surface area of the resin substrate. For a resin substrate, pore dimension, pore volume, and/or total surface area is any described herein (e.g., a pore dimension greater than 90 or in a range from 60 to 400 or 1 to 200 nm; an average pore size in a range from 30 to 80 nm; a pore volume greater than 0.5 mL/g or in a range from 0.1 to 5 mL/g, 0.1 to 4 mL/g, or 0.1 to 1.5 mL/g; and/or a total surface area greater than 100 m.sup.2/g, greater than 1200 m.sup.2/g, or in a range from a range from 100 to 1200 m.sup.2/g).

    [0184] In some embodiments, the resin substrate is functionalized to provide a functional portion having an adsorbing moiety. In some embodiments, the adsorbing moiety is an amine moiety (e.g., a primary, secondary, or tertiary amine group, as described herein). In some embodiments, the amine moieties bind to the reactive sites of the resin. In some embodiments, the interaction moiety includes any that reacts with reactive sites present on the surface of the resin. Non-limiting interaction moieties are, e.g., an amine moiety (e.g., any described herein). In some embodiments, the resin includes a first amine moiety, and the reaction introduces a second amine moiety bonded to the first. By forming interactions between the interaction moiety and the surface, amine bonding stability and/or lifetime of the sorbent is improved in some embodiments. The functionalization methods herein can be applicable to all form factors of the ion-exchange resins.

    ii. Functional Portion

    [0185] In some embodiments, the functional portion includes any combination of moieties, groups, or compounds to facilitate adsorption of desired gases by the sorbent. In some embodiments, the functional portion includes an adsorbing moiety and an interaction moiety. Whereas the adsorbing moiety is configured to adsorb a desired gas, the interaction moiety is configured to attach (directly or indirectly) the adsorbing moiety to the substrate surface. Optionally, the interaction moiety is further configured to stabilize the functional portion, such as by forming bonds with the adsorbing moiety and/or the substrate surface. In another optional embodiment, the interaction moiety further provides an additional adsorbing moiety to enhance adsorption of the sorbent. In some embodiments, the functional portion includes any useful combination of one or more adsorbing moieties (e.g., one or more amine moieties) with one or more interaction moieties (e.g., one or more silane moieties). In some embodiments, when a plurality of amine moieties is present (e.g., when a first amine moiety and a second amine moiety are present), such moieties react with or bind to carbon dioxide.

    [0186] As seen in FIGS. 1A-1C, in some embodiments the surface 103A-C of the substrate 102A-C is functionalized to provide a functional portion 106A-C. In some embodiments (e.g., as in FIG. 1A), the functional portion 106A includes an interaction moiety 108A bonded to an adsorbing moiety 110A. In some embodiments (e.g., as in FIG. 1C), the functional portion 106B includes an interaction moiety 108B bonded to a first adsorbing moiety 110B and includes a second adsorbing moiety 112B associated with the interaction moiety 108B and/or the first adsorbing moiety 110B. In some embodiments (e.g., as in FIG. 1C), the functional portion 106C includes an adsorbing moiety.

    [0187] In some embodiments, the functional portion includes an adsorbing moiety. In some embodiments, the adsorbing moiety includes one, two, three, or more amine moieties (e.g., any described herein). In some embodiments, the amine moiety includes one or more of the following: a primary amine (e.g., NH.sub.2), a secondary amine (e.g., NHR.sup.N1, in which R.sup.N1 can be any described herein that is not hydrogen), a tertiary amine (e.g., NR.sup.N1R.sup.N2, in which each of R.sup.N1 and R.sup.N2 can be any described herein that is not hydrogen), an aminoalkyl group (e.g., -Ak-NR.sup.N1R.sup.N2), a terminal amine group (e.g., NR.sup.N1R.sup.N2), an internal amine group (e.g., NR.sup.N3, such as NH), a linked group (e.g., N(-L.sup.1-NR.sup.N1R.sup.N2); N(-L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2); N[-L.sup.2-N(-L.sup.1-NR.sup.N1R.sup.N2).sub.2]; -L.sup.1-NR.sup.N1R.sup.N2; NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2; -L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2; NR.sup.N4-L.sup.2-NR.sup.N3-L.sup.1NR.sup.N1R.sup.N2; [0188] or -L.sup.3-NR.sup.N4-L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2), an aminoalkylamino group (e.g., NR.sup.N3-Ak-NR.sup.N1R.sup.N2), an aminoalkylaminoalkyl group (e.g., -Ak-NR.sup.N3-Ak-NR.sup.N1R.sup.N2 or -Ak-N(-Ak-NR.sup.N1R.sup.N2).sub.2), a linked group including amino and silane groups (e.g., -L.sup.1-SiR.sup.S1R.sup.S2NR.sup.N1R.sup.N2, -L.sup.2SiR.sup.S1R.sup.S2-L.sup.1-NR.sup.N1R.sup.N2, and -L.sup.3-SiR.sup.S1R.sup.S2-L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2), a nitrogen-containing heterocyclyl (e.g., optionally substituted piperazinyl, such as unsubstituted piperazinyl or piperazinyl substituted with optionally substituted alkyl, aminoalkyl, hydroxyalkyl, amino, etc.), and the like.

    [0189] In other embodiments, the adsorbing moiety includes one or more R.sup.A moieties described herein. In some embodiments, R.sup.A is or includes NH, NR.sup.N1, N(-L.sup.1-NR.sup.N1R.sup.N2), N(-L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2), N[-L.sup.2-N(-L.sup.1-NR.sup.N1R.sup.N2).sub.2], NH.sub.2, NR.sup.N1R.sup.N2, -L.sup.1-NR.sup.N1R.sup.N2, N R.sup.N3-L.sup.1-NR.sup.N1R.sup.N2, -L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2, or NR.sup.N4-L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2.

    [0190] The amine moiety includes any combination of linkers and R.sup.A moieties. In some implementations, the amine moiety includes one or more of the following: -L.sup.1-[R.sup.A1-L.sup.2].sub.n1-R.sup.A2; NR.sup.N1[L.sup.1-NR.sup.N2].sub.n1-L.sup.2-NR.sup.N3R.sup.N4; NH-[L-NH].sub.nH; N[L-NH.sub.2].sub.2; NH [CH.sub.2CH.sub.2NH],H; [CH.sub.2CH.sub.2NH],R.sup.N1; [CH.sub.2CH.sub.2NH].sub.n; [CH.sub.2CH.sub.2NR.sup.A],R.sup.N1; [CH.sub.2C H.sub.2NR.sup.A].sub.n; and the like.

    [0191] In some non-limiting embodiments for any amine moiety herein, each of R.sup.A, R.sup.A1 or R.sup.A2 is or includes any described herein for R.sup.A; each of R.sup.N1 and R.sup.N2 is any described herein; each of R.sup.N3, R.sup.N4, and R.sup.N5 is any described herein for R.sup.N1 and R.sup.N2; each of R.sup.S1 and R.sup.S2 can be any described herein; each of L, L.sup.1, L.sup.2, or L.sup.3 is independently a linker; each Ak is independently optionally substituted alkylene; and each of n and n1 is independently an integer (e.g., an integer of 1 or more, such as from 1-25000, 1-24000, 1-23000, 1-22000, 1-21000, 1-20000, 1-19000, 1-18000, 1-17000, 1-16000, 1-15000, 1-14000, 1-13000, 1-12000, 1-11000, 1-10000, 1-7500, 1-5000, 1-4000, 1-3000, 1-2000, 1-1000, 1-500, 1-100, 1-50, 1-20, 1-10, 1-5, 2-25000, 2-24000, 2-23000, 2-22000, 2-21000, 2-20000, 2-19000, 2-18000, 2-17000, 2-16000, 2-15000, 2-14000, 2-13000, 2-12000, 2-11000, 2-10000, 2-7500, 2-5000, 2-4000, 2-3000, 2-2000, 2-1000, 2-500, 2-100, 2-50, 2-20, 2-10, 2-5, 5-25000, 5-24000, 5-23000, 5-22000, 5-21000, 5-20000, 5-19000, 5-18000, 5-17000, 5-16000, 5-15000, 5-14000, 5-13000, 5-12000, 5-11000, 5-10000, 5-7500, 5-5000, 5-4000, 5-3000, 5-2000, 5-1000, 5-500, 5-100, 5-50, 5-20, 5-10, as well as ranges therebetween).

    [0192] In some embodiments, R.sup.A, R.sup.A1, or R.sup.A2 is or

    [0193] includes NH, NR.sup.N1, N(-L.sup.1-NR.sup.N1R.sup.N2), N(-L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2), N[-L.sup.2-N(-L.sup.1-NR.sup.N1R.sup.N2).sub.2], NH.sub.2, NR.sup.N1R.sup.N2, -L.sup.1-NR.sup.N1R.sup.N2, NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2, -L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2, or NR.sup.N4-L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2.

    [0194] In some embodiments, each of R.sup.N1, R.sup.N2, R.sup.N3, R.sup.N4, and R.sup.N5 is, independently, hydrogen (H), halo (e.g., F, Cl, Br, or I), hydroxy (e.g., OH), optionally substituted alkyl, optionally substituted aminoalkyl, optionally substituted hydroxyalkyl, optionally substituted alkoxy (e.g., OR, in which R is an optionally substituted alkyl), optionally substituted aryl, optionally substituted aryloxy (e.g., OR, in which R is an optionally substituted aryl), trialkylsilyloxy (e.g., OSiR.sub.3, in which each R is independently an optionally substituted alkyl), or trialkoxylsilyloxy (e.g., OSi[OR].sub.3, in which each R is independently an optionally substituted alkyl. In some embodiments, each of R.sup.N1, R.sup.N2, R.sup.N3, R.sup.N4, R.sup.N5, and R is, independently, H, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aromatic, or optionally substituted heteroaromatic.

    [0195] In some embodiments, each of R.sup.S1 and R.sup.S2 is, independently, a side group (e.g., any described herein), a leaving group (e.g., halo, acyl, acyloxy, and the like), a reactive group (e.g., hydroxy, halo, alkoxy, and the like), hydrogen (H), optionally substituted alkyl, optionally substituted heteroalkyl, optionally substituted aryl, optionally substituted amine, or an R.sup.A moiety (e.g., any described herein); or R.sup.S1 and R.sup.S2, taken together with the silicon atom to which each are attached, form a heterocyclyl group. In some embodiments, each of R.sup.S1 and R.sup.S2 is independently hydrogen (H), optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aromatic, or optionally substituted heteroaromatic.

    [0196] In some embodiments, the linker includes, for example, a covalent bond, an atom (e.g., carbonyl, oxy, thio, imino, and the like), optionally substituted alkylene, optionally substituted heteroalkylene, optionally substituted arylene, or optionally substituted heteroarylene.

    [0197] In some embodiments, the functional portion includes an interaction moiety. In some embodiments, the interaction moiety includes one, two, three, or more silane moieties (e.g., any described herein). In some embodiments, the interaction moiety comprises one or more SiO bonds.

    [0198] In some embodiments, the silane moiety includes an alkoxysilane group (e.g., Si(OAk).sub.d(X).sub.3-d or Si(OAk).sub.d1(X).sub.2-d1 or Si(OAk).sub.d(X).sub.2-aR.sup.A); a trialkoxysilane group (e.g., SiR.sup.S1R.sup.S2R.sup.S3, in which each of R.sup.S1, R.sup.S2, and R.sup.S3 is, independently, alkoxy; such as trimethoxysilane or triethoxysilane); a dialkoxysilane group (e.g., e.g., SiR.sup.S1R.sup.S2R.sup.S3 or SiR.sup.S1R.sup.S2, in which each of R.sup.S1 and R.sup.S2 is, independently, alkoxy, and a R.sup.3 is a side group, a leaving group, a reactive group, or any described herein); a monoalkoxysilane group (e.g., SiR.sup.S1R.sup.S2R.sup.S3 or SiR.sup.S1R.sup.S2, in which R.sup.S1 is alkoxy, and each of R.sup.S2 and R.sup.S3 is independently a side group, a leaving group, a reactive group, or any described herein); a dialkoxysilanol group (e.g., Si(OR).sub.2OH, in which each R is independently alkyl); a monoalkoxysilanol group (e.g., Si(OR)(R.sup.S1) OH, in which each R is independently alkyl and R.sup.S1 is a side group, a leaving group, a reactive group, or any described herein); a hydrosilane group (e.g., SiH.sub.3 or SiH.sub.2); a monoalkylsilane group (e.g., SiR.sup.S1R.sup.S2R.sup.S3 or SiR.sup.S1R.sup.S2, in which R.sup.S1 is alkyl, and each of R.sup.S2 and R.sup.S3 is independently a side group, a leaving group, a reactive group, or any described herein; in which non-limiting examples of monoalkylsilane is alkyldialkoxysilane or alkyldihalosilane); a dialkylsilane group (e.g., SiR.sup.S1R.sup.S2R.sup.S3 or SiR.sup.S1R.sup.S2, in which each of R.sup.S1 and R.sup.S2 is independently alkyl, and R.sup.S3 is a side group, a leaving group, a reactive group, or any described herein; in which non-limiting examples of dialkylsilane includes dialkylalkoxysilane or dialkylhalosilane); a trihalosilane group (e.g., SiZ.sub.3, in which each Z is independently halo, such as trichlorosilane); a dihalosilane group (e.g., SiZ.sub.2R.sup.S1, in which each Z is independently halo and each of R.sup.S1 is a side group, a leaving group, a reactive group, or any described herein); a monohalosilane group (e.g., SiZR.sup.S1R.sup.S2, in which Z is halo and each of R.sup.S1 and R.sup.S2 is independently a side group, a leaving group, a reactive group, or any described herein); a silanetriol group (e.g., Si(OH).sub.3); or a hydroxysilane group (e.g., Si(OH)R.sup.S1, Si(OH).sub.2, or Si(OH).sub.3).

    [0199] In some non-limiting embodiments for any silane moiety herein, Ak is optionally substituted aliphatic, alkyl, or alkylene; each X is, independently, a side group, a reactive group, or a leaving group, as any described herein; d is an integer of 1, 2, or 3; and d1 is an integer of 1 or 2. In some embodiments, each of R.sup.S1, R.sup.S2, and R.sup.S3 is, independently, a side group (e.g., any described herein), a leaving group (e.g., halo, acyl, acyloxy, and the like), a reactive group (e.g., hydroxy, halo, alkoxy, and the like), hydrogen (H), optionally substituted alkyl, optionally substituted heteroalkyl, optionally substituted aryl, optionally substituted amine, or an R.sup.A moiety (e.g., any described herein); or R.sup.S1 and R.sup.S2, taken together with the silicon atom to which each are attached, form a heterocyclyl group. In some embodiments, each of R.sup.S1 and R.sup.S2 is independently hydrogen (H), optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aromatic, or optionally substituted heteroaromatic.

    [0200] In some embodiments, any useful combination of moieties is present. For example, in some embodiments, the functional portion includes a combination of one or more adsorbing moieties, a combination of one or more interaction moieties, a combination of an adsorbing moiety with an interaction moiety, and a combination of one or more adsorbing moieties with one or more interaction moieties.

    [0201] In some embodiments, the functional portion is provided in any useful manner. For example, in some embodiments, a compound having both the adsorbing moiety and the interaction moiety is provided to a substrate. A non-limiting example of such a compound includes an aminosilane comprising an amino moiety (e.g., as the adsorbing moiety) and a silane moiety (e.g., as the interaction moiety). In some embodiments, the compound has a long-chain multi-amine containing moiety. In some embodiments, the compound has a silane moiety, which is chemically bonded to a surface of each of the particles (e.g., porous silica particles) serving as the substrate.

    [0202] In another example, a plurality of compounds is used to provide the one or more adsorbing moieties and one or more interaction moieties. For instance, in some embodiments, a first compound includes both an adsorbing moiety and an interaction moiety, and a second compound includes one or more adsorbing moieties. A non-limiting example includes a first compound that is an aminosilane comprising an amino moiety (e.g., as the adsorbing moiety) and a silane moiety (e.g., as the interaction moiety) that is used in combination with a second compound that is a polyamine comprising a plurality of amino moieties (e.g., as the adsorbing moieties). In some embodiments, the first compound is attached to a surface of the substrate (e.g., by way of one or more covalent bonds or non-covalent bonds), and the second compound is or is not attached to the substrate. In some embodiments, the second compound interacts with the first compound (or a portion thereof). In some embodiments, the second compound interacts with the first compound (or a portion thereof) and with the substrate surface. In some embodiments, such attachments and interactions include covalent and/or non-covalent bonding interactions. Non-covalent bonding interactions include, without limitation, hydrogen bonding, ionic interactions, halogen bonding, electrostatic interactions, n bond interactions, hydrophobic interactions, inclusion complexes, clathration, van der Waals interactions, and combinations thereof.

    [0203] Upon providing one or more compounds to a substrate, reactions can occur to provide covalent and/or non-covalent bonding interactions, thereby providing a functional portion disposed on the substrate surface. Non-limiting examples of compounds for providing a functional portion include amines, aminosilanes, polymers, polyamines, as well as others described herein.

    a. Aminosilanes

    [0204] In some embodiments, the compound is an aminosilane. For example and without limitation, the substrate surface (e.g., a silica substrate surface) is functionalized with an aminosilane compound including a silane moiety bonded to an amine moiety. In turn, in some embodiments, the surface includes a functional group having the silane moiety and the amine moiety. As used herein, such moieties also include reacted forms of these moieties (e.g., a reacted form of a silane moiety upon reacting with a surface of the substrate) that may be present upon forming one or more bonds, as would be understood by a skilled artisan.

    [0205] In some embodiments, the aminosilane include at least one silane moiety (e.g., one, two, three, or more silane moieties) and at least one amine moiety (e.g., one, two, three, or more amine moieties). Non-limiting examples of aminosilane compounds, silane moieties, and amine moieties are described herein.

    [0206] In some embodiments, the aminosilane compound includes one, two, three, or more silane moieties. In some embodiments, the silane moiety includes a trialkoxysilane (e.g., SiR.sup.S1R.sup.S2R.sup.S3, in which each of R.sup.S1, R.sup.S2, and R.sup.S3 is, independently, alkoxy; such as trimethoxysilane or triethoxysilane), a dialkoxysilane (e.g., SiR.sup.S1R.sup.S2R.sup.S3, in which each of R.sup.S1 and R.sup.S2 is, independently, alkoxy, and R.sup.S3 is a leaving group or a reactive group, such as any described herein), a dialkoxysilanol group (e.g., Si(OR).sub.2OH, in which each R is independently alkyl), a hydrosilane group (e.g., SiH.sub.3), a monoalkylsilane group (e.g., SiR.sup.S1R.sup.S2R.sup.S3, in which R.sup.S1 is alkyl, and each of R.sup.S2 and R.sup.S3 is independently a leaving group or a reactive group, such as any described herein; in which non-limiting examples of monoalkylsilane is alkyldialkoxysilane or alkyldihalosilane), a dialkylsilane group (e.g., SiR.sup.S1R.sup.S2R.sup.S3, in which each of R.sup.S1 and R.sup.S2 is independently alkyl, and R.sup.S3 is a reactive group or a leaving group, such as any described herein; in which non-limiting examples of dialkylsilane includes dialkylalkoxysilane or dialkylhalosilane), a trihalosilane group (e.g., SiZ.sub.3, in which each Z is independently halo, such as trichlorosilane), or a silanetriol (e.g., Si(OH).sub.3). In some embodiments, higher numbers (e.g., three or more) of silane moieties in the aminosilane compound increase the covalent bond stability with the substrate as higher numbers of siloxane bonds between the silane moieties and the substrate surface can increase. Additionally, in some embodiments, a silane group forms up to three siloxane bonds (SiOSi) to the surface, which increases stability. In some embodiments, the number of siloxane bonds that are formed by silane moiety depends on the composition of the side groups (e.g., one or more of X.sup.1, X.sup.2, and/or X.sup.3) capable of forming siloxane bonds (e.g., OMe, OEt, Cl, OH, or a combination of any of these).

    [0207] In some embodiments, the aminosilane compound includes one, two, three, or more amine moieties. In some embodiments, the amine moiety includes a primary amine (e.g., NH.sub.2), a secondary amine (e.g., NHR.sup.N1, in which R.sup.N1 is any R.sup.S1 described herein that is not hydrogen), a tertiary amine (e.g., NR.sup.N1R.sup.N2, in which each of R.sup.N1 and R.sup.N2 is respectively any R.sup.S1 and R.sup.S2 described herein that is not hydrogen), or an aminoalkyl group (e.g., -Ak-NR.sup.N1R.sup.N2, in which Ak is optionally substituted alkylene and each of R.sup.N1 and R.sup.N2 is respectively any R.sup.S1 and R.sup.S2 described herein). In some embodiments, each of R.sup.N1 and R.sup.N2 is, independently, hydrogen (H), halo (e.g., F, Cl, Br, or I), hydroxy (e.g., OH), optionally substituted alkyl, optionally substituted aminoalkyl, optionally substituted hydroxyalkyl, optionally substituted alkoxy (e.g., OR, in which R is an optionally substituted alkyl), optionally substituted aryl, optionally substituted aryloxy (e.g., OR, in which R is an optionally substituted aryl), trialkylsilyloxy (e.g., OSiR.sub.3, in which each R is independently an optionally substituted alkyl), or trialkoxylsilyloxy (e.g., OSi[OR].sub.3, in which each R is independently an optionally substituted alkyl. In some embodiments, each of R.sup.N1, R.sup.N2, and R is, independently, H, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aromatic, or optionally substituted heteroaromatic.

    [0208] In some embodiments, the amine moiety includes more than one amine group connected through various linkers (e.g., any described herein for L). For instance, in some embodiments, the amine moiety includes a terminal amine group (e.g., NR.sup.N1R.sup.N2), one or more internal amine groups (e.g., NR.sup.N3), and a linker (e.g., -L-) disposed between the terminal and internal amine groups, where R.sup.N1, R.sup.N2, and R.sup.N3 are respectively any R.sup.S1, R.sup.S2, and R.sup.S3 described herein. Non-limiting examples of amine moieties include an aminoalkylamino group (e.g., NR.sup.N3-Ak-NR.sup.N1R.sup.N2, in which Ak is optionally substituted alkylene and each of R.sup.N1, R.sup.N2, and R.sup.N3 is respectively any R.sup.S1, R.sup.S2, and R.sup.S3 described herein) or an aminoalkylaminoalkyl group (e.g., -Ak-NR.sup.N3-Ak-NR.sup.N1R.sup.N2, in which each Ak is independently optionally substituted alkylene and each of R.sup.N1, R.sup.N2, and R.sup.N3 is respectively any R.sup.S1, R.sup.S2, and R.sup.S3 described herein described herein). In some embodiments, each of R.sup.N1, R.sup.N2, and R.sup.N3 is, independently, hydrogen (H), halo (e.g., F, Cl, Br, or I), hydroxy (e.g., OH), optionally substituted alkyl, optionally substituted aminoalkyl, optionally substituted hydroxyalkyl, optionally substituted alkoxy (e.g., OR, in which R is an optionally substituted alkyl), optionally substituted aryl, optionally substituted aryloxy (e.g., OR, in which R is an optionally substituted aryl), trialkylsilyloxy (e.g., OSiR.sub.3, in which each R is independently an optionally substituted alkyl), or trialkoxylsilyloxy (e.g., OSi[OR].sub.3, in which each R is independently an optionally substituted alkyl. In some embodiments, each of R.sup.N1, R.sup.N2, R.sup.N3, and R is, independently, H, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aromatic, or optionally substituted heteroaromatic.

    [0209] In some embodiments, higher numbers (e.g., three or more) of amine moieties in the aminosilane compound increase the adsorption ability of a sorbent. In some embodiments, amine moieties interact with other moieties and groups to stabilize stability of the functional group.

    [0210] In some embodiments, an amine moiety (e.g., amine groups) of one aminosilane interacts with a neighboring aminosilane (e.g., with silane moieties or side groups within a silane moiety of the neighboring aminosilane). Alternatively, an amine moiety of one aminosilane does not interact with a neighboring aminosilane (e.g., does not interact with silane moieties or side groups within a silane moiety of the neighboring aminosilane). In yet another embodiment, an amine moiety of one aminosilane interacts with other groups, moieties, or compounds (e.g., present in another compound, such as a polyamine or another type of aminosilane). In some embodiments, an amine moiety (e.g., which can be an amine group) of the aminosilane interacts with a polyamine (e.g., an amine moiety of a polyamine).

    [0211] In some embodiments, the aminosilane compound has any useful structure. In one non-limiting example, the aminosilane includes a structure having formula (I):


    [R.sup.A].sub.aSi[X].sub.4-a(I),

    where each R.sup.A is, independently, an amine moiety comprising at least one amine group, each X is, independently, a side group, a reactive group, or a leaving group, and a is an integer from 1 to 4.

    [0212] In some embodiments, the amine moiety (e.g., R.sup.A) includes one or more amine groups. In one instance, the amine group is NR.sup.N1R.sup.N2 or NR.sup.N1, in which each of R.sup.N1 and R.sup.N2 is, independently, hydrogen (H), halo (e.g., F, Cl, Br, or I), hydroxy (e.g., OH), optionally substituted alkyl, optionally substituted aminoalkyl, optionally substituted hydroxyalkyl, optionally substituted alkoxy (e.g., OR, in which R is an optionally substituted alkyl), optionally substituted aryl, optionally substituted aryloxy (e.g., OR, in which R is an optionally substituted aryl), trialkylsilyloxy (e.g., OSiR.sub.3, in which each R is independently an optionally substituted alkyl), or trialkoxylsilyloxy (e.g., OSi[OR].sub.3, in which each R is independently an optionally substituted alkyl). In some embodiments, each of R.sup.N1, R.sup.N2, and R is, independently, H, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aromatic, or optionally substituted heteroaromatic.

    [0213] In some embodiments, the amine moiety (e.g., R.sup.A) includes one, two, three, or more amine groups. In other embodiments, the amine moiety includes a terminal amine group (e.g., as NR.sup.N1R.sup.N2) and/or an internal amine group (e.g., as NR.sup.N1).

    [0214] Non-limiting examples of amine moieties (e.g., R.sup.A) include NR.sup.N1R.sup.N2, -L-NR.sup.N1R.sup.N2, NR.sup.N3-L-NR.sup.N1R.sup.N2, -L.sup.1-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2, -L.sup.3-NR.sup.N4-L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2, -L.sup.2-SiR.sup.S1R.sup.S2-L.sup.1-NR.sup.N1R.sup.N2, and -L.sup.3-SiR.sup.S1R.sup.S2-L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2, in which each of R.sup.N1, R.sup.N2, R.sup.S1, and R.sup.S2 are described herein; in which each of R.sup.N3 and R.sup.N4 are described herein for R.sup.N1 and R.sup.N2; and in which each L, L.sup.1, L.sup.2, or L.sup.3 is independently a linker. Non-limiting examples of linkers include, e.g., a covalent bond, an atom (e.g., carbonyl, oxy, thio, imino, and the like), optionally substituted alkylene, optionally substituted heteroalkylene, optionally substituted arylene, or optionally substituted heteroarylene. In some non-limiting embodiments, each of R.sup.N1, R.sup.N2, R.sup.N3, R.sup.N4, R.sup.S1, and R.sup.S2 is, independently, H, optionally substituted aliphatic, or optionally substituted alkyl. Other examples of R.sup.N1, R.sup.N2, and R.sup.N3 are described herein.

    [0215] In some embodiments, the aminosilane includes a reactive group, a leaving group, or another group (e.g., X). Non-limiting examples of such groups include H, halo (e.g., F, Cl, Br, or I), hydroxy (e.g., OH), optionally substituted alkyl, optionally substituted aminoalkyl, optionally substituted hydroxyalkyl, optionally substituted alkoxy (e.g., OR, in which R is an optionally substituted alkyl), optionally substituted aryl, optionally substituted aryloxy (e.g., OR, in which R is an optionally substituted aryl), or optionally substituted alkanoyloxy. In some embodiments, X is, independently, H, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aromatic, or optionally substituted heteroaromatic.

    [0216] In one non-limiting example, the aminosilane includes a structure having formula (Ia):


    R.sup.A1SiX.sup.1X.sup.2X.sup.3(Ia),

    where R.sup.A1 is an amine moiety comprising at least one amine group; and each of X.sup.1, X.sup.2, and X.sup.3 is, independently, a side group, a reactive group, or a leaving group. Each of R.sup.A1, X.sup.1, X.sup.2, and X.sup.3 is any described herein for R.sup.A and X, respectively. An example of formula IA is shown in FIG. 2A (where the terms R.sup.A1 and R.sup.A are interchangeable).

    [0217] In another non-limiting example, the aminosilane includes a structure having formula Ib, Ic, Id, or Ie:


    R.sup.A1-L.sup.1-SiX.sup.1X.sup.2X.sup.3(Ib),


    R.sup.N1R.sup.N2N-L.sup.1-SiX.sup.1X.sup.2X.sup.33(Ic),


    R.sup.A1-L.sup.1-R.sup.A2-L.sup.2-SiX.sup.1X.sup.2X.sup.3(Id), or


    R.sup.N1R.sup.N2N-L.sup.1-N(R.sup.N3)-L.sup.2-SiX.sup.1X.sup.2X.sup.3(Ie),

    where N stands for Nitrogen, each R.sup.A1 or R.sup.A2 is, independently, an amine moiety comprising at least one amine group, each of R.sup.N1, R.sup.N2, and R.sup.N3 is any described herein, each of X.sup.1, X.sup.2, and X.sup.3 is, independently, a side group, a reactive group, or a leaving group, and each of L.sup.1 and L.sup.2 is a linker. In some embodiments, each of R.sup.A1, R.sup.A2, X.sup.1, X.sup.2, X.sup.3, L.sup.1, and L.sup.2 is any described herein for R.sup.A, X, and L, respectively. In some embodiments, each of X.sup.1, X.sup.2, and X.sup.3 is, independently, H, halo, optionally substituted alkyl (e.g., optionally substituted C.sub.1-3 alkyl), or optionally substituted alkoxy (e.g., optionally substituted C.sub.1-3 alkoxy). In other embodiments, each of X.sup.1, X.sup.2, and X.sup.3 is, independently, optionally substituted alkoxy (e.g., optionally substituted C.sub.1-3 alkoxy). In yet other embodiments, L is optionally substituted alkylene (e.g., optionally substituted C.sub.1-12, C.sub.1-10, C.sub.1-8, or C.sub.1-6 alkylene).

    [0218] In yet another non-limiting example, the aminosilane has the structure of formula If:


    R.sup.A1R.sup.A2R.sup.A3SiX.sup.1(If),

    where each R.sup.A1, R.sup.A2, or R.sup.A3 is, independently, an amine moiety comprising at least one amine group; and X.sup.1 is a side group, a reactive group, or a leaving group. In some embodiments, each of R.sup.A1, R.sup.A2, R.sup.A3, and X.sup.1 is any described herein for R.sup.A and X, respectively.

    [0219] In some embodiments, the aminosilane has the structure of formula II:


    [R.sup.B].sub.bN[Y].sub.3-b(II),

    where each R.sup.B is, independently, a silane moiety comprising at least one silane group, N is nitrogen, each Y is, independently, H, optionally substituted alkyl, or optionally substituted aryl, and b is an integer from 1 to 3. In some embodiments, each Y is, independently, H, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aromatic, or optionally substituted heteroaromatic. One example of formula II is illustrated in FIG. 2F. Another example of formula II is illustrated in FIG. 2G.

    [0220] In some embodiments, the silane moiety (e.g., R.sup.B) includes one or more silane groups. In some embodiments, the silane group is SiR.sup.S1R.sup.S2R.sup.S3 or SiR.sup.S1R.sup.S2, in which each of R.sup.S1, R.sup.S2, and R.sup.S3 is, independently, hydrogen (H), halo (e.g., F, Cl, Br, or I), hydroxy (e.g., OH), optionally substituted alkyl, optionally substituted aminoalkyl, optionally substituted hydroxyalkyl, optionally substituted alkoxy (e.g., OR, in which R is an optionally substituted alkyl), optionally substituted aryl, optionally substituted aryloxy (e.g., OR, in which R is an optionally substituted aryl), trialkylsilyloxy (e.g., OSiR.sub.3, in which each R is independently an optionally substituted alkyl), or trialkoxylsilyloxy (e.g., OSi[OR].sub.3, in which each R is independently an optionally substituted alkyl). In some embodiments, each of R.sup.S1, R.sup.S2, R.sup.S3, and R is, independently, H, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aromatic, or optionally substituted heteroaromatic.

    [0221] In some embodiments, the silane moiety (e.g., R.sup.B) includes one, two, three, or more silane groups. In other embodiments, the silane moiety includes a terminal silane group (e.g., as SiR.sup.S1R.sup.S2R.sup.S3) and an internal silane group (e.g., as SiR.sup.S1R.sup.S2).

    [0222] Non-limiting examples of silane moieties (e.g., R.sup.B) include-SiR.sup.S1R.sup.S2R.sup.S3, Si(OR.sup.S1)(R.sup.S2)(R.sup.S3), Si(OR.sup.S1) (OR.sup.S2)(R.sup.S3), Si(OR.sup.S1) (OR.sup.S2) (OR.sup.S3), -L-SiR.sup.S1R.sup.S2R.sup.S3, -L-Si(O R.sup.S1)(R.sup.S2)(R.sup.S3), -L-Si(OR.sup.S1) (OR.sup.S2)(R.sup.S3), -L-Si(OR.sup.S1)(OR.sup.S2)(OR.sup.S3), SiR.sup.S4R.sup.S5-L-SiR.sup.S1R.sup.S2R.sup.S3, and -SiR.sup.S1R.sup.S2NR.sup.N1R.sup.N2, in which each of R.sup.S1, R.sup.S2, R.sup.S3, R.sup.N1, and R.sup.N2 is any described herein, in which each of R.sup.S4 and R.sup.S5 is any described herein for R.sup.S1, R.sup.S2, and R.sup.S3; and in which L is a linker. Examples of linkers include, e.g., a covalent bond, an atom (e.g., carbonyl, oxy, thio, imino, and the like), optionally substituted alkylene, optionally substituted heteroalkylene, optionally substituted arylene, or optionally substituted heteroarylene. In some non-limiting embodiments, each of R.sup.S1, R.sup.S2, R.sup.S3, R.sup.S4, R.sup.S5, R.sup.N1, and R.sup.N2 is, independently, H, optionally substituted aliphatic, or optionally substituted alkyl.

    [0223] In one non-limiting example, the aminosilane has the structure of formula IIa:


    R.sup.B1NY.sup.1Y.sup.2(IIa),

    where N is nitrogen, R.sup.B1 is a silane moiety comprising at least one silane group (e.g., any described herein for R.sup.B) and each of Y.sup.1 and Y.sup.2 is any described herein for Y (e.g., a side group, a reactive group, or a leaving group).

    [0224] In another non-limiting example, the aminosilane has the structure of formula IIb, IIc, or IId:


    R.sup.B1R.sup.B2NY.sup.1(IIb),


    [R.sup.S1R.sup.S2R.sup.S3Si-L.sup.1-]NY.sup.1Y.sup.2(IIc), or


    [R.sup.S1R.sup.S2R.sup.S3Si-L.sup.1-]NY.sup.1[-L.sup.2-SiR.sup.S1R.sup.S2R.sup.S3](IId),

    where N is nitrogen, each R.sup.B1 or R.sup.B2 is, independently, a silane moiety comprising at least one silane group, each of Y.sup.1 and Y.sup.2 is, independently, a side group, a reactive group, or a leaving group, each of R.sup.S1, R.sup.S2, and R.sup.S3 is any described herein; and each of L.sup.1 and L.sup.2 is a linker. Each of R.sup.B1, R.sup.B2, Y.sup.1, Y.sup.2, L.sup.1, and L.sup.2 is any described herein for R.sup.B, Y, and L, respectively.

    [0225] FIGS. 2A-2C depict an examples of an aminosilane 206 having an amine moiety 210 (denoted as R.sup.A) and a non-limiting silane moiety 208 having three potential interaction sites or side groups (denoted as X.sup.1, X.sup.2, and X.sup.3). Side groups X.sup.1-X.sup.3 are occupied by functional groups which include, but are not limited to, a methoxy group (OMe), an ethoxy group (OEt), a chloro (Cl), a hydroxy group (OH), a hydrogen (H), or an alkyl group (e.g., a linear alkyl group such as (CH.sub.2).sub.n(CH.sub.3), in which n is an integer from 0-10; or a branched alkyl group). Yet other examples of functional groups can include any reactive or leaving group described herein. Non-limiting examples of functional groups for X can include halo, as well as optionally substituted aliphatic, alkyl, alkoxy, alkanoyloxy, heteroaliphatic, heteroalkyl, aromatic, aryl, aryloxy, and the like.

    [0226] In some embodiments, the amine moieties 210 (e.g., which can be amine groups) of one aminosilane interact with one or more of the side groups 208 of a neighboring aminosilane. In alternative embodiments, amine moieties 210 do not interact with other side groups. In yet other embodiments, the amine moieties 210 interact with other groups, moieties, or compounds (e.g., present in another compound, such as a polyamine or another type of aminosilane). In some embodiments, the amine moieties 210 (e.g., which can be amine groups) of aminosilane 208 interact with a polyamine.

    [0227] Optionally, a further linker is present between the amine moiety and the silane moiety of the aminosilane compound. For example, in some embodiments a linker is present between the amine moiety 210 and the silane moiety 208. In some embodiments, the aminosilane includes R.sup.A-L-SiX.sup.1X.sup.2X.sup.3, in which R.sup.A is an amine moiety (e.g., any described herein), L is a linker (e.g., any described herein), and each of X.sup.1, X.sup.2, and X.sup.3 is a side group, a reactive group, or a leaving group (e.g., any described herein).

    [0228] In some embodiments, an aminosilane 206 has any combination of these functional groups, e.g., amine moiety 210 and side groups 208 (e.g., which can include side group X.sup.1, side group X.sup.2, or side group X.sup.3), and must have at least one amine moiety 210 and at least one side group 208 (e.g., OMe, OEt, Cl, OH, H, alkyl, or others described herein) capable of forming a siloxane bond (e.g., an SiO or SiOSi linkage). FIG. 2B is a non-limiting example of a 3-aminopropyl group which, in some examples, serves as one or more side groups 208 (e.g., one or more of X.sup.1, X.sup.2, and X.sup.3) or amine moiety 210. FIG. 2C is an example of an N-(2-aminoethyl)-3-aminopropyl group which, in some examples, serves as one or more amine moieties 210.

    [0229] As non-limiting examples, FIGS. 2D-2G indicate examples of aminosilanes having side groups and amine moieties. In some embodiments, the aminosilane is an alkylalkoxyaminosilane having a formula of R.sup.A (Ak) Si(OAk) d, in which each of c and d is 1 or 2; R.sup.A is an amine moiety (e.g., any described herein); and each of Ak is, independently, an optionally substituted alkyl. Non-limiting examples of alkylalkoxyaminosilane include 3-aminopropyl(diethoxy)methylsilane (FIG. 2D) and 3-(ethoxydimethylsilyl)propylamine (FIG. 2E).

    [0230] In some embodiments, the aminosilane is an aminosilanetriol having the formula (HO).sub.3SiRA, in which R.sup.A is an amine moiety (e.g., any described herein). A non-limiting example of aminosilanetriol is (3-((2-aminoethyl)amino)propyl) silanetriol (FIG. 2F).

    [0231] In some embodiments, the aminosilane is a haloaminosilane having the formula (R.sup.A).sub.3SiX, in which each R.sup.A is, independently, an amine moiety (e.g., any described herein) and X is halo (e.g., any described herein). Non-limiting examples of haloaminosilane include tris(dimethylamino) chlorosilane (FIG. 2G), tris(ethylmethylamino) chlorosilane, and the like.

    [0232] In some embodiments, the aminosilane 108 has the structure of formula IIIa:

    ##STR00002##

    [0233] In formula IIIa, Q is (CP.sub.2).sub.n where n is 2, 3, 4, or 5, and each P is independently a hydrogen, hydroxy, or halogen. In one embodiment, each P is halogen and n is 3:CH.sub.2CH.sub.2CH.sub.2 (e.g., compounds 1302, 1304, 1306, 1308, 1310, 1312, 1314, 1322, 1324, and 1326 of FIG. 14).

    [0234] In formula IIIa, each R.sub.1, R.sub.2, and R.sub.3 is independently hydrogen, alkyl, a substituted alkyl, an alkylene, or a substituted alkylene. In some embodiments, each R.sub.1, R.sub.2, and R.sub.3 is CH.sub.3, CH.sub.2CH.sub.3, or CH.sub.2CH.sub.2CH.sub.3. In one embodiment, each R.sub.1, R.sub.2, and R.sub.3 is hydrogen (e.g., compounds 1308, 1312 and 1314 of FIG. 13). In one embodiment, each R.sub.1, R.sub.2, and R.sub.3 is CH.sub.2CH.sub.3 (e.g., compound 1304 of FIG. 13). In one embodiment, each R.sub.1, R.sub.2, and R.sub.3 is -CH.sub.3 (e.g., compounds 1302, 1306, 1322, 1324, 1326, and 1328 of FIG. 13).

    [0235] In formula IIIa, each R.sub.4 and R.sub.5 is independently hydrogen, a substituted alkane, a substituted alkylene, an aryl, or a substituted aryl.

    [0236] In some embodiments R.sub.4 and R.sub.5 are each methyl (e.g., compound 1328 of FIG. 13)

    [0237] In one embodiment one of R.sub.4 and R.sub.5 is (CH.sub.2).sub.mNH(R.sub.5), where m is 1, 2, 3, 4 or 5, and R.sub.5 is hydrogen or a substituted alkane, while the other of R.sub.4 and R.sub.5 is hydrogen.

    [0238] In one embodiment R.sub.4 is (CH.sub.2).sub.mNH(R.sub.6), where m is 1, 2, 3, 4 or 5, and R.sub.6 is hydrogen or a substituted alkane, and R.sub.4 is hydrogen. In some such embodiments, m is 2 and R.sub.6 is hydrogen:CH.sub.2CH.sub.2NH.sub.2 (e.g., compounds 1306 and 1308 of FIG. 13). In other embodiments, R.sub.6 is (CH.sub.2).sub.pNH(R.sub.7), where p is m is 1, 2, 3, 4 or 5, and R.sub.7 is hydrogen or a substituted alkane. In one embodiment, R.sub.7 is (CH.sub.2)(CH.sub.2)NH.sub.2 (e.g., compound 1314 of FIG. 13).

    [0239] In some embodiments, the aminosilane 108 has the structure of formula IIIb:

    ##STR00003##

    [0240] In formula IIIb, Q is (CP.sub.2).sub.n where n is 2, 3, 4, or 5, and each P is independently a hydrogen, hydroxy, or halogen. In one embodiment, each P is halogen and n is 3:CH.sub.2CH.sub.2CH.sub.2(e.g., compounds 1302, 1304, 1306, 1308, 1310, 1312, 1314, 1320, 1322, 1324, and 1326 of FIG. 13).

    [0241] In formula IIIb, each R.sub.1, R.sub.2, and R.sub.3 is independently hydrogen, alkyl, a substituted alkyl, an alkylene, a substituted alkylene, an alkoxy, or a substituted alkoxy. In some embodiments, R.sup.1 and R.sup.2 are each OCH.sub.2CH.sub.3, and R.sub.3 is CH.sub.3 (e.g., compound 1320 of FIG. 13).

    [0242] In formula IIIa, each R.sub.4 and R.sub.5 is independently hydrogen, a substituted alkane, a substituted alkylene, an aryl, or a substituted aryl.

    [0243] In some embodiments R.sub.4 and R.sub.5 are each methyl (e.g., compound 1328 of FIG. 13).

    [0244] In some embodiments R.sub.4 and R.sub.5 are each hydrogen (e.g., compound 1320 of FIG. 13).

    [0245] In some embodiments, one of R.sub.4 and R.sub.5 is (CH.sub.2).sub.mNH(R.sub.5), where m is 1, 2, 3, 4 or 5, and R.sub.5 is hydrogen or a substituted alkane, while the other of R.sub.4 and R.sub.5 is hydrogen.

    [0246] In some embodiments, R.sub.4 is (CH.sub.2).sub.mNH(R.sub.6), where m is 1, 2, 3, 4 or 5, and R.sub.6 is hydrogen or a substituted alkane, and R.sub.5 is hydrogen. In some such embodiments, m is 2 and R.sub.6 is hydrogen:CH.sub.2CH.sub.2NH.sub.2 (e.g., compounds 1306 and 1308 of FIG. 13). In other embodiments, R.sub.6 is (CH.sub.2).sub.pNH(R.sub.7), where p is m is 1, 2, 3, 4 or 5, and R.sub.7 is hydrogen or a substituted alkane. In one embodiment, R.sub.7 is (CH.sub.2)(CH.sub.2)NH.sub.2 (e.g., compound 1314 of FIG. 13).

    [0247] In some embodiments, the aminosilane 108 has the structure of formula IV:

    ##STR00004##

    [0248] In formula IV, each R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 is independently hydrogen, alkyl, a substituted alkyl, an alkylene, or a substituted alkylene. In one embodiment, each R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 is CH.sub.3 (e.g., compound 1318 of FIG. 13). In one embodiment, each R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 is CH.sub.3 or CH.sub.2CH.sub.3 (e.g., compound 1413 of FIG. 13). In formula IV, X is halogen. In one embodiment, X is Cl (e.g., compounds 1413 and 1413 of FIG. 13).

    [0249] In some embodiments, the amine moieties of the aminosilane 108 interact with one or more of the X.sup.1-X.sup.3 sites of neighboring aminosilanes 108 or interact with polymeric amines 110. In some embodiments, the amine moiety is or includes an amine group such as the amine groups of FIGS. 2B and 2C, which depict example aminopropyl, and N-(2-aminoethyl)-3-aminopropyl groups, respectively. In some implementations, the amine moiety is a primary, secondary, or tertiary amine. For example, in some embodiments, the amine moiety includes one or more aminopropyl or diethylenetriamine groups. In some implementations, the amine moiety includes more than one amine group connected through various alkyl groups. For instance, in some embodiments, the amine moiety includes a terminal amine group, an internal amine group, and a linker disposed between the terminal and internal amine group.

    [0250] Optionally, in some embodiments, a further linker is present between the amine moiety and the silane moiety of the aminosilane compound.

    [0251] Other non-limiting examples of aminosilanes include (3-aminopropyl) trimethoxysilane (compound 1302 in FIG. 13), (3-aminopropyl)triethoxysilane (compound 1304 in FIG. 13), [3-(2-aminoethylamino)propyl]trimethoxysilane (compound 1306 in FIG. 13), N-(2-aminoethyl)-3-aminopropyl silanetriol (compound 1308 in FIG. 13),.sup.N1-(3-trimethoxysilylpropyl)diethylenetriamine (compound 1310 in FIG. 13), 3-aminopropylsilanetriol (compound 1312 in FIG. 13), N-(2aminoethyl)-3-aminopropylsilanetriol (compound 1314 in FIG. 14), tris(ethylmethylamino) chlorosilane (compound 1316 in FIG. 14), tris(dimethylamino) chlorosilane (compound 1318 in FIG. 13), an aminosilane oligomer (e.g., such as VPS SIVO 280, a modified organofunctional polysiloxane from Evonik Industries AG, Essen, Germany), 3-aminopropyl(diethoxy)methylsilane (compound 1320 in FIG. 13), N-[3-(trimethoxysilyl)propyl]ethylenediamine (compound 1322 in FIG. 13), bis(3-(methylamino)propyl)-trimethoxysilane, bis[3-(trimethoxysilyl)propyl]amine (compound 1324 in FIG. 13), N-[3-(trimethoxysilyl)propyl]aniline (compound 1326 in FIG. 13), or (N,N-dimethylamino propyl) trimethoxysilane (compound 1328 in FIG. 13).

    b. Silanes

    [0252] In some embodiments, a silane compound includes any compound having a SiR.sup.S1R.sup.S2R.sup.S3 moiety or a SiR.sup.S1R.sup.S2-moiety, in which each of R.sup.S1, R.sup.S2, and R.sup.S3 is any described herein. In some embodiments, each of R.sup.S1, R.sup.S2, and R.sup.S3 is, independently, H, optionally substituted aliphatic, alkyl, heteroaliphatic, heteroalkyl, aromatic, aryl, amine, or others described herein; or R.sup.S1 and R.sup.S2, taken together with the silicon atom to which each are attached, form a heterocyclyl group. In some embodiments, each of R.sup.S1, R.sup.S2, and R.sup.S3 is, independently, hydrogen (H), halo (e.g., F, Cl, Br, or I), hydroxy (e.g., OH), optionally substituted alkyl, optionally substituted aminoalkyl, optionally substituted hydroxyalkyl, optionally substituted alkoxy (e.g., OR, in which R is an optionally substituted alkyl), optionally substituted aryl, optionally substituted aryloxy (e.g., OR, in which R is an optionally substituted aryl), trialkylsilyloxy (e.g., OSiR.sub.3, in which each R is independently an optionally substituted alkyl), or trialkoxylsilyloxy (e.g., OSi[OR].sub.3, in which each R is independently an optionally substituted alkyl).

    [0253] In some embodiments, the silane includes one or more amino moieties, such as in an aminosilane compound (e.g., any described herein).

    [0254] In some embodiments, the silane does not include an amino moiety. In one non-limiting example, the silane has formula (V):


    [R.sup.C1].sub.nSi[X].sub.4-n(V),

    where each R.sup.C1 does not comprise amino; each X is, independently, a side group, a reactive group, or a leaving group (e.g., any described herein); and a is an integer from 1 to 4.

    [0255] In some embodiments, R.sup.C1 is optionally substituted aliphatic, heteroaliphatic, alkyl, aromatic, heteroaromatic, or aryl, where the optional substituent is not amino (e.g., as defined herein). In some embodiments, R.sup.C1 is a branched, optionally substituted aliphatic, heteroaliphatic, alkyl, aromatic, heteroaromatic, or aryl. In some embodiments, R.sup.C1 is a hydrophobic group (e.g., optionally substituted C.sub.4-30 aliphatic, heteroaliphatic, alkyl, perfluoroalkyl, cycloalkyl, aromatic, heteroaromatic, or aryl). Non-limiting examples of hydrophobic groups include optionally substituted C.sub.4-24, C.sub.6-24, C.sub.8-24, C.sub.4-18, C.sub.6-18, C.sub.8-18 alkyl, haloalkyl, perfluoroalkyl, cycloalkyl, and the like (e.g., hexyl, octyl, nonyl, decyl, dodecyl, perfluorohexyl, perfluorooctyl, cyclohexyl, and cyclopentyl).

    [0256] In some embodiments, the silane has formula (Va):


    [X].sub.3Si-L-Si[X].sub.3(Va),

    where L is a linker (e.g., any described herein) and each X is, independently, a side group, a reactive group, or a leaving group (e.g., any described herein).

    [0257] Examples of linkers include, e.g., a covalent bond, an atom (e.g., carbonyl, oxy, thio, imino, and the like), optionally substituted alkylene, optionally substituted heteroalkylene, optionally substituted arylene, or optionally substituted heteroarylene. Other examples of linkers include any described herein (e.g., described herein for L, L.sup.1, L.sup.2, and L.sup.3).

    [0258] In some embodiments, the silane includes a reactive group, a leaving group, or another group (e.g., X). Non-limiting examples of such groups include hydrogen (H), halo (e.g., F, Cl, Br, or I), hydroxy (e.g., OH), optionally substituted alkyl, optionally substituted aminoalkyl, optionally substituted hydroxyalkyl, optionally substituted alkoxy (e.g., OR, in which R is an optionally substituted alkyl), optionally substituted aryl, optionally substituted aryloxy (e.g., OR, in which R is an optionally substituted aryl), optionally substituted alkanoyloxy, trialkylsilyloxy (e.g., OSiR.sub.3, in which each R is independently an optionally substituted alkyl), or trialkoxylsilyloxy (e.g., OSi[OR].sub.3, in which each R is independently an optionally substituted alkyl). In some embodiments, X is, independently, H, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aromatic, or optionally substituted heteroaromatic.

    [0259] In some embodiments, a silane is employed as a crosslinker or as an additive for any composition or use herein (e.g., for any coating, surface functionalization layer, functionalization mixture, pre-functionalization mixture, and the like). Non-limiting examples of silanes include 1,2-bis(triethoxysilyl) ethane (BTESE) and 1,2-bis(trimethoxysilyl) ethane (BTME).

    c. Polyamines

    [0260] As described herein, in some embodiments the functional portion is provided by any useful compound or combination of compounds. In some embodiments, the compound is a polyamine. In some embodiments, the polyamine includes any compound or moiety having two or more amine moieties. In some embodiments, the polyamine is a non-polymeric compound, in which the polyamine does not include repeating units. In some embodiments, the polyamine is a polymeric compound (e.g., as in a polymeric polyamine). In other embodiments, the polyamine is an oligomeric compound (e.g., as in an oligomeric polyamine). Unless otherwise specified, discussion related to polymeric and oligomeric forms of compounds is applied interchangeably. In some embodiments, the polyamine includes dimeric, trimeric, tetrameric, pentameric, hexameric, and higher order amines. In some embodiments, the polyamine is a small molecule polyamine (e.g., having a molecular weight between 100 g/mol and 800 g/mol). In some embodiments, the polyamine is a large molecule polyamine (e.g., having a MW greater than 800 g/mol).

    [0261] In some embodiments, a polyamine is used alone or with other compounds (e.g., any described herein, such as an aminosilane and the like). In some embodiments, the polyamine is used in the presence of aminosilane. In some embodiments, a first polyamine (e.g., having a high MW, such as any described herein) is used in the presence of a second polyamine (e.g., having a low MW, such as any described herein).

    [0262] In some embodiments, a high molecular weight includes a weight-average molecular weight (Mw) or number-average molecular weight (Mn) of greater than 300 daltons (Da), 400 Da, 500 Da, or 600 Da or from a range of 300 to 1,000,000 Da (e.g., 300 to 900000 Da, 300 to 800000 Da, 300 to 700000 Da, 300 to 600000 Da, 300 to 500000 Da, 300 to 400000 Da, 300 to 300000 Da, 300 to 200000 Da, 300 to 100000 Da, 300 to 90000 Da, 300 to 80000 Da, 300 to 70000 Da, 300 to 60000 Da, 300 to 50000 Da, 300 to 40000 Da, 300 to 30000 Da, 300 to 20000 Da, 300 to 10000 Da, 300 to 9000 Da, 300 to 8000 Da, 300 to 7000 Da, 300 to 6000 Da, 300 to 5000 Da, 300 to 4000 Da, 300 to 3000 Da, 300 to 2000 Da, 300 to 1000 Da, 500 to 1000000 Da, 500 to 900000 Da, 500 to 800000 Da, 500 to 700000 Da, 500 to 600000 Da, 500 to 500000 Da, 500 to 400000 Da, 500 to 300000 Da, 500 to 200000 Da, 500 to 100000 Da, 500 to 90000 Da, 500 to 80000 Da, 500 to 70000 Da, 500 to 60000 Da, 500 to 50000 Da, 500 to 40000 Da, 500 to 30000 Da, 500 to 20000 Da, 500 to 10000 Da, 500 to 9000 Da, 500 to 8000 Da, 500 to 7000 Da, 500 to 6000 Da, 500 to 5000 Da, 500 to 4000 Da, 500 to 3000 Da, 500 to 2000 Da, 500 to 1000 Da, 700 to 1000000 Da, 700 to 900000 Da, 700 to 800000 Da, 700 to 700000 Da, 700 to 600000 Da, 700 to 500000 Da, 700 to 400000 Da, 700 to 300000 Da, 700 to 200000 Da, 700 to 100000 Da, 700 to 90000 Da, 700 to 80000 Da, 700 to 70000 Da, 700 to 60000 Da, 700 to 50000 Da, 700 to 40000 Da, 700 to 30000 Da, 700 to 20000 Da, 700 to 10000 Da, 700 to 9000 Da, 700 to 8000 Da, 700 to 7000 Da, 700 to 6000 Da, 700 to 5000 Da, 700 to 4000 Da, 700 to 3000 Da, 700 to 2000 Da, 700 to 1000 Da, 800 to 1000000 Da, 800 to 900000 Da, 800 to 800000 Da, 800 to 700000 Da, 800 to 600000 Da, 800 to 500000 Da, 800 to 400000 Da, 800 to 300000 Da, 800 to 200000 Da, 800 to 100000 Da, 800 to 90000 Da, 800 to 80000 Da, 800 to 70000 Da, 800 to 60000 Da, 800 to 50000 Da, 800 to 40000 Da, 800 to 30000 Da, 800 to 20000 Da, 800 to 10000 Da, 800 to 9000 Da, 800 to 8000 Da, 800 to 7000 Da, 800 to 6000 Da, 800 to 5000 Da, 800 to 4000 Da, 800 to 3000 Da, 800 to 2000 Da, or 800 to 1000 Da). In some embodiments, the high MW polyamine includes linear or branched forms. In some embodiments, the high MW polyamine includes a plurality of primary amine moieties and/or a plurality of secondary amine moieties. In some embodiments, the high molecular weight polyamine is provided in polymeric form.

    [0263] In some embodiments, the low molecular weight includes a weight-average molecular weight (Mw) or number-average molecular weight (Mn) of less than 300 Da, from a range of 30 to 300 Da, from a range of 100 to 800 Da, or ranges therebetween (e.g., 30 Da to 800 Da, 30 Da to 700 Da, 30 Da to 500 Da, 30 Da to 200 Da, 30 Da to 100 Da, 50 Da to 800 Da, 50 Da to 700 Da, 50 Da to 600 Da, 50 Da to 500 Da, 100 Da to 700 Da, 100 Da to 600 Da, 100 Da to 500 Da, 100 Da to 400 Da, 100 Da to 300 Da, 150 Da to 800 Da, 150 Da to 700 Da, 150 Da to 600 Da, 150 Da to 500 Da, 150 Da to 400 Da, 150 Da to 300 Da, 200 Da to 800 Da, and 300 Da to 800 Da). In some embodiments, the low molecular weight polyamine (e.g., which can be considered to be an oligomeric amine) includes linear or branched forms. In some embodiments, the low MW polyamine includes a plurality of primary amine moieties and/or a plurality of secondary amine moieties. In some embodiments, the low molecular weight polyamine is provided in oligomeric form.

    [0264] Without wishing to be limited by mechanism, in some embodiments high molecular weight (MW) amines are useful for their lower volatility (e.g., as compared to low MW amines). In some embodiments, higher MW polyamines are characterized by a higher viscosity, which makes handling more difficult. Higher MW polyamines are generally more expensive. In some non-limiting embodiments, polyamines with high relative concentrations of primary and secondary amine moieties are employed. In some non-limiting embodiments, tertiary amine moieties are characterized by lower performance for DAC applications and are less desired. Secondary amines have higher oxidation resistance equating to longer operational lifetimes. Primary amines have higher reactivity equating to higher performance at low CO.sub.2 concentrations (DAC conditions).

    [0265] The polyamine can have any useful structure. In one non-limiting example, the polyamine has the structure of any one of formula (VIa) to (VIi):

    ##STR00005##
    R.sup.A1-[L.sup.1-R.sup.A2].sub.n1-L.sup.2-R.sup.A3(VId)


    R.sup.N1R.sup.N2N-[L.sup.1-NR.sup.N3].sub.n1-L.sup.2-NR.sup.N4R.sup.N5(VIe)


    R.sup.N1R.sup.N2N-[L.sup.1-NR.sup.N3].sub.n1-L.sup.2-R.sup.C(VIf)

    ##STR00006##

    where N is nitrogen, each R.sup.A, R.sup.A1, R.sup.A2, and R.sup.A3 is, independently, an amine moiety comprising at least one amine group, each L, L.sup.1, or L.sup.2 is, independently, a linker, each of R.sup.N1, R.sup.N2, R.sup.N3, R.sup.N4, and R.sup.N5 is any described herein, optionally where R.sup.N1 and R.sup.N2, taken together with the nitrogen atom to which each are attached, can form a heterocyclyl group, as defined herein or optionally where R.sup.N4 and R.sup.N5, taken together with the nitrogen atom to which each are attached, form a heterocyclyl group, as defined herein; R.sup.C is hydrogen (H), halo, hydroxy, amino (e.g., NR.sup.N1R.sup.N2), optionally substituted aliphatic, heteroaliphatic, alkyl, hydroxyalkyl, aromatic, heteroaromatic, or aryl; n is an integer greater than 1 (e.g., from 1-25000, 1-24000, 1-23000, 1-22000, 1-21000, 1-20000, 1-19000, 1-18000, 1-17000, 1-16000, 1-15000, 1-14000, 1-13000, 1-12000, 1-11000, 1-10000, 1-7500, 1-5000, 1-4000, 1-3000, 1-2000, 1-1000, 1-500, 1-100, 1-50, 1-20, 1-10, 1-5, 2-25000, 2-24000, 2-23000, 2-22000, 2-21000, 2-20000, 2-19000, 2-18000, 2-17000, 2-16000, 2-15000, 2-14000, 2-13000, 2-12000, 2-11000, 2-10000, 2-7500, 2-5000, 2-4000, 2-3000, 2-2000, 2-1000, 2-500, 2-100, 2-50, 2-20, 2-10, 2-5, 5-25000, 5-24000, 5-23000, 5-22000, 5-21000, 5-20000, 5-19000, 5-18000, 5-17000, 5-16000, 5-15000, 5-14000, 5-13000, 5-12000, 5-11000, 5-10000, 5-7500, 5-5000, 5-4000, 5-3000, 5-2000, 5-1000, 5-500, 5-100, 5-50, 5-20, 5-10, as well as ranges therebetween); and n1 is an integer of 1 or more (e.g., from 1-1000, 1-100, 1-50, 1-20, 1-10, 5-1000, 5-100, 5-50, 5-20, 5-10, as well as ranges therebetween). In some embodiments, R.sup.A, R.sup.A1, and R.sup.A2 is any amine moiety described herein, L, L.sup.1, and L.sup.2 is any linker described herein, and each of R.sup.N1, R.sup.N2, R.sup.N3, R.sup.N4, and R.sup.N5 is any described herein for R.sup.N1 or R.sup.N2.

    [0266] In some embodiments, R.sup.A, R.sup.A1, R.sup.A2, or R.sup.A3 is or includes NH, NR.sup.N1, N(-L.sup.1-NR.sup.N1R.sup.N2), N(-L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2), N[-L.sup.2-N(-L.sup.1-NR.sup.N1R.sup.N2).sub.2], NH.sub.2, NR.sup.N1R.sup.N 2, -L.sup.1-NR.sup.N1R.sup.N2, NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2, -L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2, or NR.sup.N4-L.sup.2-NR.sup.N3-L.sup.1-NR.sup.N1R.sup.N2, in which each of R.sup.N1 and R.sup.N2 is any described herein, each of R.sup.N3 and R.sup.N4 is any described herein for R.sup.N1 and R.sup.N2; and each of L.sup.1 or L.sup.2 is independently a linker.

    [0267] Examples of linkers (e.g., for L.sup.1, L.sup.2, or L) include, e.g., a covalent bond, an atom (e.g., carbonyl, oxy, thio, imino, and the like), optionally substituted alkylene, optionally substituted heteroalkylene, optionally substituted arylene, or optionally substituted heteroarylene. In some embodiments, the linker is a monomer or a polymer, which can be employed as a backbone to which an amine moiety R.sup.A is attached. Alternatively, the backbone of the polymer itself can also include an amine moiety. Non-limiting examples of monomers include a saccharide (e.g., glucosamine, N-acetyl-glucosamine, glucose, and the like), an amino acid (e.g., lysine), an alkylene, an alkenylene, an arylene, and the like. Non-limiting examples of polymers include a polysaccharide (e.g., chitosan, chitin, and the like), a polypeptide (e.g., poly(lysine)), a vinyl polymer, and the like.

    [0268] Further non-limiting examples of polyamines include poly(lysine) (e.g., poly(L-lysine), poly(D-lysine), or poly(LD-lysine)), poly(ethyleneimine), poly(propyleneimine), poly(vinylamine), poly(N-methylvinylamine), poly(allylamine), poly(N-isopropyl acrylamide), poly(4-aminostyrene), chitosan, spermidine, spermine, norspermine, putrescine, cadaverine, tetraethylenepentamine (TEPA), triethylenetetramine (TETA), an ethylene amine/oligomeric mix (e.g., Amix 1000 having CAS No. 68910 May 4), diethylenetriamine (DETA), 2-(2-aminoethylamino) ethanol, ethylenediamine, piperazine, 2-piperazin-1-ylethylamine, 2-piperazin-1-ylethanol, pentaethylenehexamine, tetramethylethylenediamine, as well as salts thereof and/or copolymers thereof and/or mixtures thereof. In some embodiments, the polyamine includes spermidine, spermine, norspermine, putrescine, cadaverine, tetraethylenepentamine (TEPA), triethylenetetramine (TETA), ethanolamine, diethylenetriamine (DETA), piperazine, 2-piperazin-1-ylethylamine, 2-piperazin-1-ylethanol, pentaethylenehexamine, tetramethylethylenediamine, as well as polymeric forms thereof. In some embodiments, the ethylene amine/oligomeric mix includes one or more of the following: 2-(2-aminoethylamino) ethanol, trientine or TETA, 2,2-iminodi (ethylamine) or DETA, 2-aminoethanol, ethylenediamine, piperazine, 2-piperazin-1-ylethylamine, and 2-piperazin-1-ylethanol.

    [0269] In some embodiments, the polyamine is or includes H.sub.2N[CH.sub.2CH.sub.2NH],H, in which n is an integer of 1 or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more). In some embodiments, the polyamine is or includes H.sub.2N[-L-NH-],H or N[-L-NH.sub.2].sub.3, in which each L is independently a linker (e.g., any described herein, such as optionally substituted alkylene) and n is an integer of 1 or more. In some embodiments, the polyamine is or includes H.sub.2N[CH.sub.2CH.sub.2CH.sub.2NH],H, in which n is an integer of 1 or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more).

    [0270] In some embodiments, the polyamine is or includes oligomeric or polymeric forms of ethyleneimine. In some embodiments, the polyamine is or includes [CH.sub.2CH.sub.2NH].sub.n, in which n is an integer of 1 or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more). In some embodiments, the polyamine is or includes [CH.sub.2CH.sub.2NR.sup.A], in which R.sup.A is an amine moiety (e.g., any described herein) and n is an integer of 1 or more (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more). In some non-limiting embodiments, R.sup.A is -Ak-NR.sup.N1R.sup.N2 or -Ak-N(-Ak-NR.sup.N1R.sup.N2).sub.2 or -Ak-NR.sup.N1-Ak-NR.sup.N2R.sup.N3, in which N is nitrogen, Ak is optionally substituted alkylene and each of R.sup.N1, R.sup.N2, and R.sup.N3 is any described herein.

    [0271] FIGS. 2H-2K provide non-limiting, general examples of polyamine chains that can serve as a polyamine of the present disclosure. The polyamines of FIGS. 2H and 2I include repeating units composed of amine groups (e.g., NH, NR.sup.N1, NH.sub.2, or NR.sup.N1R.sup.N2) and linkers. In some examples, the linker is a carbon aliphatic-(CH.sub.2) n-spacer groups, in which n is an integer greater than one (e.g., an integer from 1 to 20, 1 to 10, 1 to 12, 1 to 6, etc.). FIG. 2H shows an n-propylene (CH.sub.2CH.sub.2CH.sub.2) (C.sub.3H.sub.6) spacer group. FIG. 2I shows an ethylene (CH.sub.2CH.sub.2) (C.sub.2H.sub.4) spacer group. The polyamine has a repeating chain portion (bracketed) having a length of n active groups in the chain portion of the polymer (e.g., if n=2, there are two repeating groups in the chain portion). Other linkers can be used, such as any described herein (e.g., optionally substituted alkylene, as described herein), as well as linkers having peptidic bonds (e.g., C(O) NH) or glycosidic linkages. Linkers can include peptides, polysaccharides, and the like. Furthermore, in some embodiments the polyamine includes linear or branched structures, such as those present in linear polymers, branched polymers, block polymers, or dendrimers.

    [0272] FIGS. 2H-2I depict a polyamine having a length of n active groups in the repeating chain portion. FIGS. 2H-2I also depict the repeating chain portion including two non-limiting amine groups (N(X)), separated by either C.sub.3 (FIG. 2H) or C.sub.2 (FIG. 2I) spacer groups. In NX, X is any side group, reactive group, leaving group, or other group described herein. For example, in some emboidments X is H, optionally substituted aliphatic, heteroaliphatic, aromatic, and the like. Furthermore, in some embodiments X further includes an amine groups. Thus, in some non-limiting embodiments, X is any R.sup.A group described herein (e.g., an aminoalkyl group, an alkylaminoalkyl group, and the like). FIG. 2I depicts the amine groups extending in different orientations from the carbon chain, whereas FIG. 2H depicts the amine groups extending in similar orientations.

    [0273] In some embodiments the polyamine is derived from natural polymers having amine moieties. For example, FIG. 2J is an example of a poly(lysine), and FIG. 2K is an example of a natural chitosan.

    [0274] In some embodiments, the amine moieties present in a polyamine interact with other moieties, groups, or compounds present in proximity to the substrate surface. In some embodiments, amine moieties of the polyamine interact with silane moieties (e.g., silanol groups or other groups) present in an aminosilane. In other embodiments, amine moieties of the polyamine interact with moieties of other polyamines, aminosilanes, or other groups present in proximity to the surface. Such interactions include covalent or non-covalent interactions (e.g., hydrogen bonding, ionic interactions, and/or others described herein) to form a network over the surface of the substrate.

    [0275] In some embodiments, the polyamine is a polymeric/oligomeric amine or a mixture including polymeric/oligomeric amine, such as poly(ethyleneimine) (PEI), poly(propyleneimine) (PPI), or a multiple amine mixture (e.g., a mixture including a plurality of amines (e.g., polyamines and/or monoamines), such as Amix 1000, CAS No. 68910 May 4, as produced by BASF SE, Ludwigshafen, Germany). In some embodiments, the polyamine is a small molecule including amine moieties (e.g., small molecule amines), an oligomer including amine moieties (e.g., an oligomeric amine), or an oligomeric including ethylene amine moieties (e.g., an oligomeric ethylene amine), such as tetraethylenepentamine (TEPA), triethylenetetramine (TETA), diethylenetriamine (DETA), ethylenediamine, polymers or oligomers of monoethanolamine, polymers or oligomers of diethanolamine, polymers or oligomers of triethanolamine, 2-(2-aminoethylamino) ethanol, piperazine, 2-piperazin-1-ylethylamine, 2-piperazin-1-ylethanol, pentaethylenehexamine, tetramethylethylenediamine, or others described herein.

    [0276] In some embodiments, the polyamine is a small molecule polyamine. In some embodiments, the small molecule polyamine is characterized by a boiling point being sufficiently high that the compounds are not lost due to a high volatility. In some embodiments, the small molecule polyamine has a boiling point of at least 170 C. In some examples, these compounds have reduced compound cost compared to alternatives.

    [0277] In some embodiments, a mixture of one or more amines described herein (e.g., an aminosilane, a polyamine such as a high molecular weight polyamine or a small molecule polyamine, and/or a monoamine) is employed, in which the presence of such amines provides a polymer or an oligomer. In some embodiments, the mixture further includes an alcohol (e.g., ROH, in which R is optionally substituted aliphatic, alkyl, hydroxyalkyl, heteroaliphatic, heteroalkyl, aromatic, or aryl).

    d. Monoamines

    [0278] As described herein, the functional portion can be provided by any useful compound or combination of compounds. In some embodiments, the compound is a monoamine. In some embodiments the monoamine is any compound or moiety having one amine group (e.g., NR.sup.N1R.sup.N2, in which R.sup.N1 and R.sup.N2 can be any described herein). In some embodiments the amine group is attached to a linker (e.g., any described herein).

    [0279] In certain embodiments, the monoamine is provided to the substrate to act as an interaction moiety or an adsorbing moiety.

    [0280] In some embodiments, the monoamine includes an aminosilane having one amine group. Other examples of monoamine compounds include an alkanolamine (e.g., HO-Ak-NR.sup.N1R.sup.N2, in which N is nitrogen, Ak is optionally substituted alkylene and each of R.sup.N1 and R.sup.N2 is any described herein, such as monoethanolamine) or an alkylamine (e.g., Ak-NR.sup.N1R.sup.N2, in which Ak is optionally substituted alkyl and each of R.sup.N1 and R.sup.N2 is any described herein, such as ethylamine or hexylamine), and the like. In some embodiments, the monoamine is a compound having a structure of formula R.sup.C1N.sup.R1R.sup.N2, in which each of R.sup.N1 and R.sup.N2 is any described herein and R.sup.C1 is optionally substituted aliphatic, heteroaliphatic, alkyl, aromatic, heteroaromatic, or aryl, where the optional substituent is not amino, as defined herein, or where R.sup.C1 does not comprise amino, as defined herein.

    e. Crosslinking Agent

    [0281] As described herein, the functional portion can be provided by any useful compound or combination of compounds. In some embodiments, the compound is a crosslinking agent. The crosslinking agent forms interactions between functional groups to form a three-dimensional network of connected molecules. In the embodiments described herein, the crosslinking agent forms interactions between one or more of the adsorbing moieties, the interaction moieties, the substrate, or a combination thereof.

    [0282] In some embodiments, the structure of crosslinking agent is given by formula (VII):


    R.sup.X1-L-[R.sup.Xn].sub.n(VII),

    where each R.sup.X1 and R.sup.Xn is, independently, a reactive group (e.g., any described herein), L is a linking moiety (e.g., any linker described herein, such as terephthalaldehyde), and n is an integer from 0 to 5. Upon reacting the reactive moieties with one or more amine groups in a functional material, a linking moiety L is provided within the functional material. In some embodiments, one or more amine groups are present in the surface modification layer, and one or more linking moieties are bound (e.g., covalently bound) to at least one of the one or more amine groups.

    [0283] Non-limiting examples of reactive groups include hydrogen (H), formyl (C(O) H), halo (e.g., F, Cl, Br, or I), hydroxyl (e.g., OH), carboxyl (e.g., CO.sub.2H), isocyanato (e.g., NCO), optionally substituted alkanoyl, optionally substituted halocarbonyl, optionally substituted oxiranyl, optionally substituted heterocyclyl, optionally substituted cyclic anhydride, optionally substituted alkyl, optionally substituted aminoalkyl, optionally substituted hydroxyalkyl, optionally substituted alkoxy (e.g., OR, in which R is an optionally substituted alkyl), optionally substituted aryl, optionally substituted aryloxy (e.g., OR, in which R is an optionally substituted aryl), optionally substituted alkanoyloxy, trialkylsilyloxy (e.g., OSi.sup.R3, in which each R is independently an optionally substituted alkyl), or trialkoxylsilyloxy (e.g., OSi[OR].sub.3, in which each R is independently an optionally substituted alkyl).

    [0284] In some embodiments, each of R.sup.X1 and R.sup.Xn is, independently, H, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aromatic, or optionally substituted heteroaromatic.

    [0285] Examples of linking moieties include e.g., a covalent bond, an atom (e.g., methylene, carbonyl, oxy, thio, imino, and the like), optionally substituted alkylene, optionally substituted heteroalkylene, optionally substituted arylene, or optionally substituted heteroarylene. Other examples of linking moieties include any described herein (e.g., described herein for L, L.sup.1, L.sup.2, and L.sup.3). The linker can be flexible or rigid.

    [0286] In some embodiments, L is optionally substituted aliphatic, heteroaliphatic, alkyl, aromatic, heteroaromatic, or aryl.

    [0287] In some embodiments, n is 2. In other embodiments, n is 3. In yet other embodiments, n is 4.

    [0288] In some embodiments, R.sup.X1 and R.sup.Xn are the same. In some embodiments, R.sup.X1 and R.sup.Xn are different.

    [0289] In some embodiments, each of R.sup.X1 and R.sup.Xn is formyl; and n is 2, 3, or 4.

    [0290] In some embodiments, each of R.sup.X1 and R.sup.Xn is halo; and n is 2, 3, or 4.

    [0291] In some embodiments, each of R.sup.X1 and R.sup.Xn is isocyanato; and n is 2, 3, or 4.

    [0292] In some embodiments, each of R.sup.X1 and R.sup.Xn is optionally substituted halocarbonyl (e.g., in which X is Cl); and n is 2, 3, or 4.

    [0293] In some embodiments, each of R.sup.X1 and R.sup.Xn is optionally substituted oxiranyl; and [0294] n is 2, 3, or 4.

    [0295] In some embodiments, each of R.sup.X1 and R.sup.Xn is optionally substituted heterocyclyl; [0296] and n is 2, 3, or 4.

    [0297] In some embodiments, each of R.sup.X1 and R.sup.Xn is optionally substituted cyclic anhydride; and n is 2, 3, or 4.

    [0298] An example of the crosslinking agent is a dialdehyde. A dialdehyde is an organic chemical compound with two aldehyde groups. In some embodiments, the dialdehyde includes a structure having the formula (VIIa) or (VIIb):


    HC(O)-L-C(O)H(VIIa) or


    HC(O)-L.sup.a-R.sup.n1(VIIb),

    where L is any described herein, R.sup.n1 is any described herein; and L.sup.a is optionally substituted with a formyl group. In some embodiments, L.sup.a is optionally substituted with one or more formyl groups. Non-limiting examples of aldehyde groups include formaldehyde, terephthalaldehyde, glutaraldehyde, and glyoxal.

    [0299] Examples of dialdehyde include 2,5-diformylfuran:

    ##STR00007##

    glutaraldehyde:

    ##STR00008##

    glyoxal:

    ##STR00009##

    hexanedial:

    ##STR00010##

    1,3-phenylenediacetaldehyde:

    ##STR00011##

    and terephthalaldehyde (TALD; 1,4-benzenedicarbaldehyde):

    ##STR00012##

    [0300] Examples of the use of TALD as a crosslinking agent are described in Examples 5 and 6.

    [0301] Another example of the crosslinking agent is a diisocyanate. A diisocyanate is an organic chemical compound with two isocyanate groups. In some embodiments, the diisocyanate includes a structure having the formula (VIIc) or (VIId):


    OCN-L-NCO(VIIc) or


    OCN-L.sup.a-R.sup.n1(VIId),

    where L is any described herein; R.sup.n1 is any described herein; and L.sup.a is optionally substituted with an isocyanato group. In some embodiments, L.sup.a is optionally substituted with one or more isocyanato groups. Non-limiting examples of diisocyanates include 2,4-diisocyanatotoluene (TDI):

    ##STR00013##

    2,6-diisocyanatotoluene (TDI):

    ##STR00014##

    methylene diphenyl diisocyanate (4,4-diisocyanatodiphenylmethane) (MDI):

    ##STR00015##

    hexamethylene diisocyanate (HDI):

    ##STR00016##

    isophorone diisocyanate:

    ##STR00017##

    a trimethylhexamethylene diisocyanate such as:

    ##STR00018##

    cyclohexane diisocyanate:

    ##STR00019##

    and xylylene diisocyanate (meta -xylylene diisocyanate):

    ##STR00020##

    [0302] Additional examples of isocynanates are Trixene BI 7960 and Trixene B1 7961 (Baxenden Chemicals Ltd., Lancashire, United Kingdom) described in Example 9.

    [0303] Another example of the crosslinking agent is a dihaloalkane. A dihaloalkane is an organic chemical compound with two haloalkane groups. In some embodiments, the halo groups are provided at the terminus of the alkylene moiety. In some embodiments, the dihaloalkane includes a structure having the formula (VIIe) or (VIIf):


    X-L-X(VIIe) or


    X-L.sup.a-R.sup.n1(VIIf),

    where L is any described herein, each X is, independently, halo (e.g., fluorine, chlorine, bromine, or iodine); R.sup.n1 is any described herein; and L.sup.a is optionally substituted with a halo groups. In some embodiments, L.sup.a is optionally substituted with one or more halo groups. In some embodiments, L or L.sup.a is optionally substituted alkylene. In some embodiments, L is unsubstituted alkylene. Non-limiting examples of dihaloalkanes include 1,4-dibromobutane:

    ##STR00021##

    1,2-dibromoethane:

    ##STR00022##

    and 1,5-dibromopentane:

    ##STR00023##

    [0304] FIG. 2L depicts a non-limiting example of a dihaloalkane having two potential reactive groups (denoted as X) and two potential substituents (denoted as R.sup.1 and R.sup.2).

    [0305] Additional examples of dihaloalkanes are of the formula:

    ##STR00024##

    where X.sup.1 and X.sup.2 are each, independently, F, Cl, Br, I, and n is 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. Example 11 illustrates the use the alkyl bromide alpha alpha dibromo-xylene (1,2-bis(bromomethyl)benzene) as a cross-linker:

    ##STR00025##

    [0306] Another example of the crosslinking agent is an epoxide, or a compound containing an optionally substituted oxiranyl functional group. An epoxide is a reactive cyclic ether. In some embodiments, the epoxide includes a structure having the formula (VIIg):


    R.sup.1R.sup.2C[O]CR.sup.3R.sup.4(VIIg),

    where each of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 is, independently, any functional group described herein. In some embodiments, each of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 is, independently, H, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aromatic, or optionally substituted heteroaromatic.

    [0307] Another example of the crosslinking agent is a diepoxide, or a compound containing two optionally substituted oxiranyl functional groups. In some embodiments, the diepoxide includes a structure having the formula (VIIh) or (VIIi):


    R.sup.X1-L-R.sup.X2(VIIh) or


    R.sup.X1-L.sup.a-R.sup.n1(VIIi),

    where L is any described herein, each R.sup.X1 and R.sup.X2 is, optionally substituted oxiranyl, R.sup.n1 is any R described herein; and L.sup.a is optionally substituted with an optionally substituted oxiranyl group. In some embodiments, L.sup.a is optionally substituted with one or more optionally substituted oxiranyl groups. Non-limiting examples of epoxides include 1,2-propylene oxide, epichlorohydrin, and bisphenol A. Non-limiting examples of diepoxides in accordance with the present disclosure include diglycidyl ether:

    ##STR00026##

    ethylene glycol diglycidyl ether:

    ##STR00027##

    3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate (and cis -isomers, trans-isomers, and mixed stereochemistry thereof):

    ##STR00028##

    neopentyl glycol diglycidyl ether:

    ##STR00029##

    and 1,4-bis(oxiran -2-ylmethyl) butane (1,4-butanediglycidyl):

    ##STR00030##

    [0308] Example 8 illustrates the use of various epoxy (diexpoxy) crosslinking agents.

    [0309] FIG. 2M depicts an example of an epoxide 220 having four potential reactive groups 222 (denoted as R.sub.1-R.sub.4).

    [0310] Another example of the crosslinking agent is a dianhydride. A dianhydride is an organic chemical compound with two anhydride groups. In some embodiments, each anhydride group includes two acyl groups bonded to the same oxygen atom. An example of a dianhydride is ethylenediaminetetraacetic (EDTA) dianhydride. In some embodiments, the dianhydride includes a structure having the formula (VIIj) or (VIIk):


    R.sup.X1-L-R.sup.X2(VIIj) or


    R.sup.X1-L.sup.a-R.sup.n1(VIIk),

    where L is any described herein; each R.sup.X1 and R.sup.X2 is, an optionally substituted cyclic anhydride group; R.sup.n1 is any described herein, and L.sup.a is optionally substituted with an optionally substituted cyclic anhydride group. In some embodiments, L.sup.a is optionally substituted with one or more optionally substituted cyclic anhydride groups. Non-limiting examples of anhydrides include glutaric anhydride, succinic anhydride, and ethylenediaminetetraacetic dianhydride.

    [0311] Nonlimiting examples of dianhydrides in accordance with the present disclosure include methylene dianhydride (MDA; 2,2-oxydioxydiethanone):

    ##STR00031##

    benzophenone-3,3,4,4-tetracarboxylic dianhydride (2,2-(4-oxocyclohexa -2,5-dien-1-ylidene)bis(benzenecarboxylic acid):

    ##STR00032##

    3,3,4,4-biphenyl dianhydride (2,2-dicarboxy-4,4-dioxo-[1,1-biphenyl]-3,3-dicarboxylic acid anhydride):

    ##STR00033##

    4,4-oxydiphthalic anhydride:

    ##STR00034##

    and 1,2,3,4-cyclohexane tetracarboxylic dianhydride such as:

    ##STR00035##

    [0312] Example 12 illustrates the use of the dianhydride 3,3,4,4-biphenyltetracarboxylic dianhydride as a crosslinker.

    [0313] Another example of the crosslinking agent is a diacid chloride. A diacid chloride is an organic chemical compound with two chlorocarbonyl functional groups. In some embodiments, the diacid chloride includes a structure having the formula (VIII) or (VIIm):


    ClC(O)-L-C(O)Cl(VIII) or


    ClC(O)-L.sup.a-R.sup.n1(VIIm),

    where L is any described herein, R.sup.n1 is any described herein; and L.sup.a is optionally substituted with a chlorocarbonyl group (e.g., C(O)Cl). In some embodiments, L.sup.a is optionally substituted with one or more optionally substituted chlorocarbonyl groups. Non-limiting examples of diacid chlorides include succinyl chloride:

    ##STR00036##

    glutaryl chloride:

    ##STR00037##

    adipoyl chloride:

    ##STR00038##

    sebacoyl chloride:

    ##STR00039##

    4,4-oxydiphthaloyl chloride:

    ##STR00040##

    and terephthaloyl chloride:

    ##STR00041##

    [0314] Example 10 illustrates the use of an diacid chloride (acid chloride) as a crosslinker.

    [0315] Another example of the crosslinking agent is a diacrylate. An example of a diacrylate is 1,6-hexanediol diacrylate:

    ##STR00042##

    [0316] Additional examples of diacrylates used as crosslinking agents are provided in Example 7.

    iii. Interaction of Moieties, Groups, or Compounds

    [0317] Any combination of moieties, groups, or compounds can be used to provide a functional portion. In some embodiments, the functional portion is provided as a coating or a surface modification layer, which in turn can be formed from a complex network of interactions between one or more silanes, aminosilanes, polymeric/oligomeric amines, monoamines, and/or surfaces of the substrate (e.g., a silica substrate).

    [0318] In some embodiments, interactions form between a surface of a substrate and a silane moiety (e.g., present in any silane, aminosilane, polymeric silane, or polymeric aminosilane described herein). In instances when the silane moiety is provided by a (poly)aminosilane, the silanol moieties on a silica surface may react with the silane moiety to form siloxane linkages, which are non-limiting examples of covalent bonds. In some embodiments, such silanol moieties are acidic and are deprotonated by basic amine moieties of the (poly)aminosilane to form an acid-base pair, which is a non-limiting example of an ionic interaction. In some embodiments, silanol moieties (on silica) and silanol and amine moieties (on (poly)aminosilanes) form a variety of hydrogen bonding interactions (e.g., by way of hydrogen bonding). In the case of large polymeric silanes, the sum of these interactions is significant in some embodiments. In some embodiments the silica and (poly) silanes are polar and possess weak dipole-dipole interactions. In the case of large polymeric silanes, the sum of these interactions is significant in some embodiments.

    [0319] In some embodiments, interactions form between the substrate surface and an amine moiety (e.g., present in any aminosilane, polyamine, or a monoamine described herein). In instances when the amine moiety is provided by a polyamine, silanol moieties on the silica surface are acidic and are deprotonated by the basic amine moieties of the polyamine to form acid-base pairs, which are non-limiting examples of ionic interactions. Silanol moieties (on silica) and amine moieties (on polyamines) form a variety of hydrogen bonding interactions in some embodiments. In some embodiments the silica and polyamines are polar and possess weak dipole-dipole interactions. Due to the large branching shape of some non-limiting polyamines, the sum of these weak interactions is significant when the polyamine adheres to or otherwise interacts with the silica surface in some embodiments.

    [0320] In some embodiments, interactions form between substrate surfaces (e.g., a first surface and a second surface of a silica substrate). In instances when the substrate comprises silica, silica -silica interactions contribute to the formation and strength of the silica substrate in some embodiments. In some embodiments, silica substrates are composed of a single polymeric silica -dioxide molecule. In the case of precipitated silica, the silica substrate is e composed of a great number of small nucleites that are entangled into larger aggregates and finally agglomerated into the full particle and held together by physical interactions in some embodiments. In some embodiments silicon dioxide forms siloxane (SiOSi) linkages between individual silicon atoms, in which such siloxane linkages are non-limiting examples of covalent bonds. In some embodiments silica nucleites and aggregates are physically entangled and agglomerated to form substrate particles, in which such entanglement and agglomeration interactions are non-limiting examples of physical interactions. The surface of silica nucleites and aggregates include silanol moieties that form many hydrogen bonding interactions that promote cohesion in some embodiments. In some embodiments such silica nucleites and aggregates are polar and form cohesive dipole-dipole interactions.

    [0321] In some embodiments, interactions form between silane moieties (e.g., present in any silane, aminosilane, or polymeric aminosilane described herein). In instances when the silane moieties are provided by alkoxysilane groups or silanol groups, the silane moieties react with each other to form siloxane condensation bonds in some embodiments. Both a silica surface and silanes can include silanol moieties that can condense to form siloxane bonds in some embodiments. This process is repeated many times to form branching polysilane networks having covalent bonds in some embodiments. In some embodiments silanols or polysilanes include acidic silanol moieties that are deprotonated by basic amine moieties (e.g., present in aminosilane) to form acid-base interactions, which are non-limiting examples of ionic interactions. In some embodiments the silanols or polysilanes of the present disclosure have silanol and amino moieties that form a variety of hydrogen bonding interactions. In some embodiments large branching polysilanes become physically entangled with each other. In some embodiments silanols and polysilanes are polar molecules and possess weak dipole-dipole interactions with each other. In the case of large branching polysilanes, the sum of these weak interactions is significant in some embodiments.

    [0322] In some embodiments, interactions form between amine moieties (e.g., present in any amine, polyamine, aminosilane, or polymeric aminosilane). In instances when the amine moieties are provided by polyamines, polyamines have a variety of amine moieties that can donate and accept hydrogen bonds in some embodiments. Since polyamines are polymers, a higher number of these intermolecular interactions are possible (e.g., by way of hydrogen bonding) in some embodiments. Large polyamines become physically entangled with each other in some embodiments. In some embodiments polyamines are polar molecules and possess some weak dipole-dipole interactions with each other. In the case of large branching shapes present in some polyamines, the sum of these interactions can be significant in some embodiments.

    [0323] In some embodiments, interactions form between an amino moiety (e.g., present in any amine, polyamine, aminosilane, or polymeric aminosilane). and a silane moiety (e.g., present in any silane, polymeric silane, aminosilane, or polymeric aminosilane). In instances when the amine moieties are provided by polyamines, polyamines have a plurality of basic amine moieties, which can deprotonate acidic silanol moieties (in (poly) silane) to form acid-base interactions in some embodiments. In the case of large polyamines interacting with large polysilanes, the sum of these interactions is even more significant (e.g., by way of ionic interactions) in some embodiments. In some embodiments, polyamines have many amine moieties, that form a variety of hydrogen bonding interactions with silanol moieties (in (poly) silane) and amine moieties. In the case of large polyamines interacting with large polysilanes, the sum of these interactions is even more significant (hydrogen bonding) in some embodiments. In some embodiments, polyamines and (poly) silanes are polar molecules and possess some weak dipole-dipole interactions with each other. In the case of large polyamines interacting with large polysilanes, the sum of these interactions is significant in some embodiments.

    iv. Additives

    [0324] In some embodiments the compositions of the present disclosure further include additives. Such additives include any described herein, including one or more chelating agents, antioxidants, and the like.

    [0325] In some embodiments, additives are included in the functionalization mixtures to extend the operational lifetime of the functionalized material. For example, the addition of bis[3-(trimethoxysilyl)propyl]amine (BTMSPA) to the mixture increases the operational lifetime of the functionalized material of the present disclosure in some embodiments. BTMSPA is an aminosilane having two ends, in which each end has a trimethoxysilyl reactive group. The BTMSPA bonds on the substrate with six binding points, as contrasted with the three binding points for an aminosilane with a single reactive group, such as would be present in a compound having a methoxydialkylsilyl reactive group. The increased number of binding points increases binding stability with the silica substrate in some embodiments. The BTMSPA forms a network with other aminosilanes and polyamines on the surface that increases binding stability of the overall network in some embodiments.

    [0326] Other examples of additives include a polyamine (e.g., any described herein). Yet other examples of additives include 1,2-bis(triethoxysilyl) ethane (BTESE), other bisaminosilane compounds (e.g., X.sup.1X.sup.2X.sup.3Si-L.sup.1-NRN-L.sup.2-SiX.sup.4X.sup.5X.sup.6, in which each of X.sup.1, X.sup.2, X.sup.3, X.sup.4, X.sup.5, and X.sup.6 is any described herein for X; each of L.sup.1 and L.sup.2 is any described herein for L; and RN is any described herein for R.sup.N1), or other bissilane compounds (e.g., X.sup.1X.sup.2X.sup.3Si-L.sup.1-SiX.sup.4X5X.sup.6, in which each of X.sup.1, X.sup.2, X.sup.3, X.sup.4, X.sup.5, and X.sup.6 is any described herein for X and L.sup.1 is any described herein for L).

    [0327] In some embodiments, the functionalized material includes antioxidant additives. Without wishing to be limited by theory, an additive prevents the degradation of the amine moieties by atmospheric oxygen and/or extends the cycling lifetime of the functionalized material of the present disclosure in some embodiments. For example, in some embodiments the antioxidant additives are organic sulfur-containing compounds, such as 2,2-thiodiethanol, 2-hydroxyethyl disulfide, and 3,3-dithiodipropionic acid. In some embodiments, the organic sulfur-containing compound has the formula RSR or RSSR or R'S-L-SR, in which each of R and R is, independently, aliphatic, alkyl, hydroxyalkyl, carboxyalkyl, aromatic, aryl, hydroxyaryl, or carboxyaryl (e.g., as defined herein), in which each of these is optionally substituted; and L is a linker (e.g., any described herein).

    [0328] Another example of antioxidant additives is a metal catalyst chelator. Without wishing to be limited by theory or mechanism, transition metal impurities (e.g., such as iron or copper) increase the oxidation rate of amine moieties, which in turn reduces the lifetime of the sorbent. In some embodiments, a catalyst chelator includes, e.g., a phosphate or phosphonate alkali salt (e.g., a phosphate or phosphonate sodium salt), an aminopolycarboxylic acid or a salt thereof (e.g., ethylenediaminetetraacetic acid tetrasodium salt dihydrate or diethylenetriaminepentaacetic acid), a phosphonic acid or a salt thereof (e.g., 1-hydroxyethane 1,1-diphosphonic acid monohydrate or ethylenediamine tetramethylene phosphonic acid), a mercapto acid (e.g., meso-2,3-dimercaptosuccinic acid, and the like. In some embodiments, one or more catalyst chelators is used to reduce the oxidation rate and improve sorbent lifetime.

    [0329] In general, the amount of antioxidant additives in the functionalized material is 5% (wt/wt) to the substrate (e.g., 3%, 4%, 6%, or 8% (wt/wt)). In some embodiments the antioxidant additives is added during any useful step (e.g., during formation of the suspension mixture or the functionalization mixture) of the following synthesis procedure or afterward (e.g., through dissolving in a solvent, such as an alcohol like methanol, and then soaking the functionalized material in the additive/solvent mixture for 1 hour).

    [0330] In some embodiments, the functionalized material includes, or is functionalized with, other hydrophobic compounds including hydrophobic silanes or hydrophobic polymer coatings. In some embodiments, the hydrophobic silane includes one, two, or three alkyl chains. In particular embodiments, the hydrophobic silane includes R.sup.1R.sup.2R.sup.3SiX.sup.1 or [R.sup.1].sub.aSi[X.sup.1].sub.4-a, in which each of R.sup.1, R.sup.2, and R.sup.3 is independently an optionally substituted aliphatic, alkyl, aromatic, or aryl; X.sup.1 is a side group, a reactive group, or a leaving group (e.g., any described herein for X); and a is 1, 2, or 3. Without wishing to be limited by theory, alkyl chains on the silane molecule increases the hydrophobicity of the silane molecule in some embodiments. When the silane molecule is bonded to the substrate, it increases the hydrophobicity of the functionalized material as well in some embodiments. Thus, the water adsorption capacity of the functionalized material is reduced, which is beneficial for some cases such as when using the sorbent in high humidity conditions in some embodiments. For the same purpose of increasing the hydrophobicity of the functionalized material, additional hydrophobic polymer coatings are used in some embodiments. Polydimethylsiloxane (PDMS), silicone oil, polyethylene, polypropylene, poly(tetrafluorethylene), and polyurethane are examples of hydrophobic polymers that re used to coat the outer surface of the functionalized silica to reduce water adsorption for high humidity applications in some embodiments.

    v. Characteristics

    [0331] In some embodiments the functionalized material of the present disclosure is used as a sorbent, which in turn can has any useful characteristics (e.g., any described herein).

    [0332] In some embodiments, the crosslinked sorbent adsorbs CO.sub.2 at concentrations similar to non-enhanced sorbents, enabling efficient capture at levels present in atmospheric conditions using stronger, longer-lasting products.

    [0333] In some embodiments, the crosslinked sorbent has increased mechanical durability compared to non-enhanced sorbents such as increased crush strength and resistance to abrasion, thus increasing the useful lifespan of the sorbent and reducing the production of fines and sorbent particulates.

    [0334] In some embodiments, crosslinking sorbent amines reduces amine volatility thereby reducing amines lost during vacuum desorption of adsorbed CO.sub.2 from the functionalized material.

    [0335] In some embodiments, crosslinking sorbent amines enhances sorbent oxidation resistance which improves operational lifetimes of the functionalized material thereby increasing adsorption/desorption cycle counts for the functionalized sorbent.

    [0336] In some embodiments, crosslinking sorbent amines reduces amine leaching thereby reducing environmental release of free amines and reducing the environmental impact of the functionalized material.

    [0337] In some embodiments, the functionalized material adsorbs CO.sub.2 at low concentrations enabling increased capture at levels present in atmospheric conditions. Capturing CO.sub.2 from atmospheric conditions can facilitate employing the functionalized material in a large number of applications.

    [0338] In some embodiments, CO.sub.2 is desorbed from the functionalized material at laboratory temperatures. This can reduce the energy required to remove captured CO.sub.2, increase the applicability of the functionalized material to more industries and environments, and/or increase the speed at which the CO.sub.2 is desorbed.

    [0339] In some embodiments, the functionalized material achieves high adsorption/desorption counts, which reduces operational costs in carbon capture systems. In some embodiments the functionalized material is enabled for repeated use of the substrate.

    [0340] In some embodiments, the functionalized material is produced using industrially available components, reducing the cost of and increasing the scalability of production.

    [0341] In some embodiments, the functionalized material includes polymeric, oligomeric, or molecular sources with high densities of amine functionality that increase uptake of CO.sub.2 per weight of dry sorbent.

    [0342] In some embodiments, functionalizing the substrate with an aminosilane compound increases the binding stability of the polymeric, oligomeric, or high density amine source, thereby increasing the useful lifespan of the functionalized material.

    [0343] In some embodiments, functionalizing the substrate with a polyamine (e.g., a high molecular weight polyamine) increases the binding stability, as compared to short chain amine functionalization (e.g., employing an oligomeric amine or a small molecular weight amine having at least two amine moieties and having a molecular weight from 100 to 800 g/mol).

    [0344] In some embodiments, functionalizing the substrate with a small molecule polyamine (e.g., an oligomeric amine, an oligomeric ethylene amine, or an ethylene amine/oligomer mixture compound) decreases the cost of the functionalized substrate and facilitates large-scale functionalization of the substrate.

    [0345] In some embodiments, polyamine sources have an increased amine density and are commercially available which increases cost effectiveness of the use of polyamine functionalized materials as sorbents.

    [0346] In some embodiments, the functionalized material is produced in a single-pot reaction in short time scales to reduce the cost of production, reduce reliance on industrial solvents, and/or reduce the environmental impact of the product.

    [0347] In some embodiments, the functionalized material is produced in a single-pot reaction in short time scales and using only water as a solvent to reduce the cost of production, reduce reliance on industrial solvents, and/or reduce the environmental impact of the product.

    [0348] In some embodiments, the functionalized material is produced in a water-based, single-pot reaction at ambient pressures and temperatures in short time scales (e.g., using a dip-coating process) to reduce the cost of production, reduce reliance on industrial solvents, and/or reduce the environmental impact of the product.

    [0349] In some embodiments, the compositions of the present disclosure adsorb atmospheric CO.sub.2 (e.g., to an adsorbing moiety, such as an amine moiety) in a first temperature range and can desorb previously adsorbed CO.sub.2 (e.g., from an adsorbing moiety, such as an amine moiety) in a second temperature range higher than the first temperature range. The second temperature range can be between 65 C. and 90 C.

    [0350] In some embodiments, the compositions of the present disclosure adsorb atmospheric CO.sub.2 (e.g., to an adsorbing moiety, such as an amine moiety) at a first gas pressure for CO.sub.2 and desorb previously adsorbed CO.sub.2 (e.g., from an adsorbing moiety, such as an amine moiety) at a second gas pressure for CO.sub.2 that is lower than the first gas pressure. In some embodiments, the second gas pressure is below 1.5 psi (e.g., for functionalized silica or other functionalized material described herein). In some embodiments, the second gas pressure is below 0.3 psi (e.g., for functionalized MOF or other functionalized material described herein). The first and second gas pressure relate to the pressure for CO.sub.2. Thus, when other gases are present in proximity of the sorbent, the first gas pressure and the second gas pressure relate to the partial pressure for CO.sub.2.

    [0351] In some embodiments, the composition adsorbs atmospheric CO.sub.2 (e.g., to an adsorbing moiety, such as an amine moiety) at a first CO.sub.2 concentration and desorbs previously adsorbed CO.sub.2 (e.g., from an adsorbing moiety, such as an amine moiety) at a second CO.sub.2 concentration lower than the first CO.sub.2 concentration. In some embodiments the first CO.sub.2 concentration is below 420 ppm or below 400 ppm.

    [0352] In some embodiments, the composition comprises or consists essentially of porous silica particles as a substrate. In some embodiments the porous silica particles include a plurality of pores. In some embodiments the plurality of pores have a dimension (e.g., a diameter) in the range between 60 and 400 or between 20 and 1000 . In some embodiments the pores have a size in the range between 100 and 150 . In some embodiments the plurality of pores can have a volume that is greater than 0.5 mL/g. In some embodiments the porous silica particles have a total surface area greater than 100 m.sup.2 per dry gram. In some embodiments the porous silica particles have an average diameter in the range between 25 m asnd 3 mm or between 25 m and 4 mm.

    [0353] In some embodiments, the porous silica particles have a greatest dimension in the range between 70 m and 80 m. In some embodiments the porous silica particles include a plurality of pores, and the plurality of pores have volume greater than 0.8 mL/g and a size of at least 90 .

    [0354] In some embodiments, the compositions of the present disclosure comprise or consist essentially of MOF particles as a substrate. In some embodiments the MOF particles include a plurality of pores. In some embodiments the plurality of pores have a dimension (e.g., a diameter) in the range between 30 and 400 . In some embodiments the plurality of pores have a volume greater than 0.5 mL/g. In some embodiments the MOF particles have a total surface area greater than 100 m.sup.2 per dry gram. In some embodiments MOF particles have an average diameter in the range between 10 m and 1 mm or between 50 and 100 m.

    [0355] In some embodiments, the compositions of the present disclosure comprise or consist essentially of resin as a substrate. In some embodiments the resin includes a plurality of pores. In some embodiments the plurality of pores have a dimension (e.g., a diameter) in the range between 1 nm and 200 nm. In some embodiments the plurality of pores have a volume greater than 0.5 mL/g. In some embodiments the resin has a total surface area greater than 100 m.sup.2 per dry gram. In some embodiments the resin has an average diameter in the range between 25 m and 4 mm.

    [0356] In some embodiments, the compositions of the present disclosure adsorb between 0.5 mol and 2.5 mol of CO.sub.2 per dry kilogram (mol CO.sub.2/kg), between 0.5 mol CO.sub.2/kg and 2 mol CO.sub.2/kg, or between 1 mol CO.sub.2/kg and 2 mol CO.sub.2/kg. In some embodiments the compositions of the present disclosure adsorb CO.sub.2 at a relative humidity in the range between 0% relative humidity (RH) and 100% RH, between 5% RH and 95% RH, or between 5% RH and 90% RH (e.g., for functionalized silica or other functionalized material described herein) or between 0% RH and 100% RH or between 5% and 60% RH (e.g., for functionalized MOF, functionalized resin, or other functionalized material described herein).

    [0357] In some embodiments, a sorbent of the present disclosure is reused through the desorption process. For example, in some embodiments any of the sorbents of the present disclosure is reused 100 times or more (e.g., 1000 times or more, 10000 times or more). For the desorption process, in some embodiments the sample (sorbent of the present disclosure) is heated to 70 C. under vacuum for 30 minutes or another duration (e.g., the duration is change based on temperature and/or vacuum level). This facilitates the CO.sub.2 captured during the adsorption process to be released, in which released CO.sub.2 is collected for further sequestration, described with reference to the systems for direct air capture herein. A non-limiting aspect of the desorption process of the present disclosure includes maintaining the sorbent to be heated under a water vapor filled vacuum environment (e.g., >10% RH) in some embodiments. In some non-limiting embodiments, this reduces sorbent degradation.

    [0358] When exposed to a gaseous mixture including CO.sub.2, the amine moiety (or other adsorbing moiety) of the sorbents of the present disclosure react with the CO.sub.2 to bond the CO.sub.2 to the functional portion. This thereby functionally adsorbs the CO.sub.2 to the substrate, in which the interaction moiety bonds the adsorbing moiety to substrate surface by way of covalent or non-covalent bonding interactions. Without wishing to be bound by theory, the total surface area, volume of the pores, and number of adsorbing moieties determines the adsorption capacity of the functionalized material of the present disclosure in some embodiments. The adsorption capacity (e.g., uptake) of the functionalized material of the present disclosure is in a range between 0.1 mol CO.sub.2/kg and 2.5 mol CO.sub.2/kg of functionalized material (e.g., between 0.1 mol CO.sub.2/kg and 2 mol CO.sub.2/kg, 0.1 mol CO.sub.2/kg and 1.8 mol CO.sub.2/kg, 0.1 mol CO.sub.2/kg and 1.5 mol CO.sub.2/kg, 0.1 mol CO.sub.2/kg and 1.2 mol CO.sub.2/kg, 0.1 mol CO.sub.2/kg and 1.0 mol CO.sub.2/kg, 0.1 mol CO.sub.2/kg and 0.5 mol CO.sub.2/kg, 0.2 mol CO.sub.2/kg and 2 mol CO.sub.2/kg, 0.2 mol CO.sub.2/kg and 1.0 mol CO.sub.2/kg, 0.2 mol CO.sub.2/kg and 0.8 mol CO.sub.2/kg, 0.5 mol CO.sub.2/kg and 2.5 mol CO.sub.2/kg, 0.5 mol CO.sub.2/kg and 2.2 mol CO.sub.2/kg, 0.5 mol CO.sub.2/kg and 2 mol CO.sub.2/kg, 0.5 mol CO.sub.2/kg and 1.8 mol CO.sub.2/kg, 0.5 mol CO.sub.2/kg and 1.5 mol CO.sub.2/kg, 0.5 mol CO.sub.2/kg and 0.8 mol CO.sub.2/kg, 0.8 mol CO.sub.2/kg and 2.5 mol CO.sub.2/kg, 0.8 mol CO.sub.2/kg and 2.2 mol CO.sub.2/kg, 0.8 mol CO.sub.2/kg and 2 mol CO.sub.2/kg, 0.8 mol CO.sub.2/kg and 1.8 mol CO.sub.2/kg, 0.8 mol CO.sub.2/kg and 1.5 mol CO.sub.2/kg, 1 mol CO.sub.2/kg and 2 mol CO.sub.2/kg, 1 mol CO.sub.2/kg and 1.4 mol CO.sub.2/kg, 1 mol CO.sub.2/kg and 1.5 mol CO.sub.2/kg, 1.2 mol CO.sub.2/kg and 2.0 mol CO.sub.2/kg, 1.2 mol CO.sub.2/kg and 1.8 mol CO.sub.2/kg, 1.5 mol CO.sub.2/kg and 2.5 mol CO.sub.2/kg, 1.5 mol CO.sub.2/kg and 2 mol CO.sub.2/kg, or 2 mol CO.sub.2/kg and 2.5 mol CO.sub.2/kg). In some embodiments, the range is greater than 0.5, 1, 1.5, 2, or 2.5 mol CO.sub.2/kg. In some implementations, the functionalized material of the present disclosure achieves CO.sub.2 adsorption capacity up to 1 mol CO.sub.2/kg or up to 2 mol CO.sub.2/kg at 420 ppm CO.sub.2 in ambient air conditions.

    [0359] In some implementations, the functionalized material (e.g., functionalized substrate including polyamine) achieves CO.sub.2 adsorption capacity in a range from 0.8 to 2.5 mol CO.sub.2/kg or 0.5 to 2.2 mol CO.sub.2/kg (e.g., from 1 to 2 mol CO.sub.2/kg, 1 to 1.5 mol CO.sub.2/kg, 1.5 to 2 mol CO.sub.2/kg, 1.5 to 2.5 mol CO.sub.2/kg, or 2 to 2.5 mol CO.sub.2/kg). In some implementations, the functionalized substrate achieves CO.sub.2 adsorption capacity up to 2 mol CO.sub.2/kg at 420 ppm CO.sub.2 in ambient air conditions.

    [0360] In some implementations, the functionalized material (e.g., functionalized substrate including ethylene amine, oligomeric ethylene amine, or mixtures thereof) achieves CO.sub.2 adsorption capacity in a range from 0.5 to 1.8 mol CO.sub.2/kg or 0.5 to 2 mol CO.sub.2/kg (e.g., from 1.5 to 2 mol CO.sub.2/kg, 1.5 to 1.8 mol CO.sub.2/kg, 1 to 1.5 mol CO.sub.2/kg, or 1.2 to 1.8 mol CO.sub.2/kg). In some implementations, the functionalized substrate achieves CO.sub.2 adsorption capacity up to 2 mol CO.sub.2/kg at 420 ppm CO.sub.2 in ambient air conditions.

    [0361] In some implementations, the functionalized material (e.g., functionalized substrate prepared by way of a dip-coating process) achieves CO.sub.2 adsorption capacity in a range from 1 to 2 mol CO.sub.2/kg. In some implementations, the functionalized substrate achieves CO.sub.2 adsorption capacity up to 2 mol CO.sub.2/kg at 420 ppm CO.sub.2 in ambient air conditions.

    [0362] In some implementations, the functionalized material (e.g., functionalized MOF) achieves CO.sub.2 adsorption capacity in a range from 0.8 to 2.5 mol CO.sub.2/kg or 0.1 to 1 mol CO.sub.2/kg (e.g., from 0.2 to 0.8 mol CO.sub.2/kg). In some implementations, the functionalized MOF substrate achieves CO.sub.2 adsorption capacity up to 2 mol CO.sub.2/kg at 420 ppm CO.sub.2 in ambient air conditions.

    [0363] In some implementations, the functionalized material (e.g., functionalized resin) achieves CO.sub.2 adsorption capacity in a range from 0.8 to 2.5 mol CO.sub.2/kg, 0.8 to 3 mol CO.sub.2/kg, or 0.1 to 2.0 mol CO.sub.2/kg (e.g., from 0.1 to 1.8 mol CO.sub.2/kg, 0.1 to 1.5 mol CO.sub.2/kg, 0.1 to 1.2 mol CO.sub.2/kg, 0.1 to 1.0 mol CO.sub.2/kg, 0.1 to 0.5 mol CO.sub.2/kg, 0.2 to 1.0 mol CO.sub.2/kg, 0.2 to 0.8 mol CO.sub.2/kg, 0.5 to 2.0 mol CO.sub.2/kg, 0.5 to 1.5 mol CO.sub.2/kg, 0.5 to 0.8 mol CO.sub.2/kg, 1.2 to 2.0 mol CO.sub.2/kg, 1.2 to 1.8 mol CO.sub.2/kg, or any ranges described herein). In some implementations, the functionalized resin achieves CO.sub.2 adsorption capacity up to 2 mol CO.sub.2/kg at 420 ppm CO.sub.2 in ambient air conditions.

    [0364] In environmental conditions, the atmosphere includes a concentration of water vapor (e.g., humidity). The functionalized material of the present disclosure is used to capture CO.sub.2 from atmospheric conditions in a range of RH levels in some embodiments. For example, in some embodiments of the present disclosure the functionalized material captures CO.sub.2 from atmospheric conditions in the range between 0% RH and 100% RH, such as for example between 5% RH and 95% RH (e.g., between 15% RH and 50% RH, between 25% RH and 40% RH, between 10% RH and 60% RH, between 5% RH and 90% RH, between 10% RH and 90% RH, or between 20% RH and 80% RH). In some embodiments, the functionalized material captures CO.sub.2 from atmospheric conditions having greater than 60% RH, greater than 75% RH, greater than 90% RH, or greater than 95% RH.

    [0365] Described herein are functionalized materials, as well as methods of forming and using such materials (e.g., as a sorbent). In some embodiments, methods include forming or using a functionalized material including a porous structure that allows gas to diffuse through the material and that provides a large surface area for gas to be captured or adsorbed. Also described herein are systems for employing such materials in various capture processes. In some embodiments, systems include sample holder, reactors, adsorbers, desorbers, and the like that employ a functionalized material (e.g., any described herein) to adsorb carbon dioxide and/or that regenerate a functionalized material (e.g., any described herein) having adsorbed carbon dioxide.

    [0366] Yet other functionalized material, methods, systems, and the like are provided in Int. Appl. No. PCT/US23/26724, filed Jun. 30, 2023, which is incorporated herein by reference in its entirety.

    [0367] vi. Chemical definitions

    [0368] Unless otherwise specified, the term material is used to encompass compounds, molecules, structures (e.g., substrates or particles), or combinations thereof (e.g., a functionalized substrate).

    [0369] As used herein, the term moiety is used to describe characteristic parts of organic molecules, compounds, or materials. For example, an amine moiety is a molecule, compound, or portion of a compound containing an amine group (e.g., NR.sup.N1R.sup.N2, as described herein), whereas a silane moiety is a molecule, compound, or portion of a compound containing a silane group (e.g., SiR.sup.S1R.sup.S2R.sup.S3, as described herein). In one non-limiting instance, an amine moiety is an aminoalkyl group (e.g., -Ak-NR.sup.N1R.sup.N2, as described herein), as may be present in an aminosilane compound or a polyamine compound. In another non-limiting instance, an amine moiety includes an amino group alone (e.g., NR.sup.N1R.sup.N2, as described herein). The term moiety is used to describe both larger molecules containing the group, or may be used to describe the group itself.

    [0370] As used herein, interact is used to describe covalent or non-covalent interactions between chemicals, such as by way of physical adsorption or ionic interactions.

    [0371] By acyl or alkanoyl, as used interchangeably herein, is meant an aliphatic or alkyl group, as defined herein, attached to the parent molecular group through a carbonyl group. In particular embodiments, the alkanoyl is C(O)-Ak, in which Ak is an aliphatic or alkyl group, as defined herein. In some embodiments, an unsubstituted alkanoyl is a C.sub.2-7 alkanoyl group. Non-limiting examples of alkanoyl groups include acetyl.

    [0372] By acyloxy or alkanoyloxy, as used interchangeably herein, is meant an acyl or alkanoyl group, as defined herein, attached to the parent molecular group through an oxy group. In particular embodiments, the alkanoyloxy is OC(O)-Ak, in which Ak is an aliphatic or alkyl group, as defined herein. In some embodiments, an unsubstituted alkanoyloxy is a C.sub.2-7 alkanoyloxy group. Non-limiting examples of alkanoyloxy groups include acetoxy.

    [0373] By acyl halide is meant-C(O) X, where X is a halogen, such as Br, F, I, or Cl.

    [0374] By aliphatic is meant a hydrocarbon group having at least one carbon atom to 50 carbon atoms (C.sub.1-50), such as one to 25 carbon atoms (C.sub.1-25), or one to ten carbon atoms (C.sub.1-10), and which includes alkanes (or alkyl, e.g., as described herein), alkenes (or alkenyl), alkynes (or alkynyl), including cyclic versions thereof, and further including straight- and branched-chain arrangements, and all stereo and position isomers as well. Such a hydrocarbon can be unsubstituted or substituted with one or more groups, such as groups described herein for an alkyl group.

    [0375] By aliphatic-aryl is meant an aryl group that is or can be coupled to a compound disclosed herein, where the aryl group is or becomes coupled through an aliphatic group, as defined herein. In some embodiments, the aliphatic-aryl group is -L-R, in which L is an aliphatic group, as defined herein, and R is an aryl group, as defined herein.

    [0376] By aliphatic-heteroaryl is meant a heteroaryl group that is or can be coupled to a compound disclosed herein, where the heteroaryl group is or becomes coupled through an aliphatic group, as defined herein. In some embodiments, the aliphatic-heteroaryl group is -L-R, in which L is an aliphatic group, as defined herein, and R is a heteroaryl group, as defined herein.

    [0377] By alkenyl is meant an optionally substituted C.sub.2-24 alkyl group having one or more double bonds. The alkenyl group can be cyclic (e.g., C.sub.3-24 cycloalkenyl) or acyclic. The alkenyl group can also be substituted or unsubstituted. For example, the alkenyl group can be substituted with one or more substitution groups, as described herein for alkyl. Non-limiting unsubstituted alkenyl groups include allyl and vinyl. In some embodiments, the unsubstituted alkenyl group is a C.sub.2-6, C.sub.2-8, C.sub.2-10, C.sub.2-12, C.sub.2-16, C.sub.2-18, C.sub.2-20, C.sub.2-24, C.sub.3-8, C.sub.3-10, C.sub.3-12, C.sub.3-16, C.sub.3-18, C.sub.3-20, or C.sub.3-24 alkenyl group. Non-limiting examples of alkenyl groups include vinyl or ethenyl (CHCH.sub.2), 1-propenyl (CHCHCH.sub.3), allyl or 2-propenyl (CH.sub.2CHCH.sub.2), 1-butenyl (CHCHCH.sub.2CH.sub.3), 2-butenyl (CH.sub.2CHCHCH.sub.3), 3-butenyl (CH.sub.2CH.sub.2CHCH.sub.2), 2-butenylidene (CH-CHCHCH.sub.3), and the like.

    [0378] By alkenylene is meant a multivalent (e.g., bivalent) form of an alkenyl group, which is an optionally substituted C.sub.2-24 alkyl group having one or more double bonds. The alkenylene group can be cyclic (e.g., C.sub.3-24 cycloalkenyl) or acyclic. The alkenylene group can be substituted or unsubstituted. For example, the alkenylene group can be substituted with one or more substitution groups, as described herein for alkyl. Non-limiting examples of alkenylene include CHCH or CHCHCH.sub.2.

    [0379] By alkoxy is meant-OR, where R is an optionally substituted aliphatic or alkyl group, as described herein. Non-limiting examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, t-butoxy, sec-butoxy, n-pentoxy, trihaloalkoxy, such as trifluoromethoxy, etc. The alkoxy group can be substituted or unsubstituted. For example, the alkoxy group can be substituted with one or more substitution groups, as described herein for alkyl. Non-limiting examples of unsubstituted alkoxy include C.sub.1-3, C.sub.1-6, C.sub.1-12, C.sub.1-16, C.sub.1-18, C.sub.1-20, or C.sub.1-24 alkoxy groups.

    [0380] By alkoxyalkyl is meant an alkyl group, as defined herein, which is substituted with an alkoxy group, as defined herein. Non-limiting examples of unsubstituted alkoxyalkyl groups include between 2 to 12 carbons (C.sub.2-12 alkoxyalkyl), as well as those having an alkyl group with 1 to 6 carbons and an alkoxy group with 1 to 6 carbons (i.e., C.sub.1-6 alkoxy-C.sub.1-6 alkyl). In some embodiments, the alkoxyalkyl group is -L-OR, in which L is an alkylene group, as defined herein, and R is an alkyl group, as defined herein.

    [0381] By alkyl and the prefix alk is meant a branched or unbranched saturated hydrocarbon group of 1 to 24 carbon atoms, such as methyl (Me), ethyl (Et), n-propyl(n-Pr), isopropyl(i-Pr), cyclopropyl, n-butyl(n-Bu), isobutyl (i-Bu), s-butyl (s-Bu), t-butyl (t-Bu), cyclobutyl, n-pentyl, isopentyl, s-pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, eicosyl, tetracosyl, and the like. In some embodiments, the alkyl group is cyclic (e.g., C.sub.3-24 cycloalkyl) or acyclic. In some embodiments, the alkyl group is branched or unbranched. In some embodiments, the alkyl group is also substituted or unsubstituted. For example, in some embodiments, the alkyl group is substituted with one or more alkenyl, alkoxy, alkynyl, amino, aryl, carboxyaldehyde (e.g., C(O) H), carboxyl (e.g., CO.sub.2H), cyano (e.g., CN), halo, nitro (e.g., NO.sub.2), oxo (e.g., O), and the like. In some embodiments, the alkyl group is substituted with one, two, three or, in the case of alkyl groups of two carbons or more, four substituents independently selected from the group consisting of: (1) C.sub.1-6 alkoxy (e.g., OR, in which R is C.sub.1-6 alkyl); (2) C.sub.1-6 alkylsulfinyl (e.g., S(O)R, in which R is C.sub.1-6 alkyl); (3) C.sub.1-6 alkylsulfonyl (e.g., SO.sub.2R, in which R is C.sub.1-6 alkyl); (4)amine (e.g., C(O) NR.sup.1R.sup.2 or NHCOR.sup.1, where each of R.sup.1 and R.sup.2 is, independently, selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof, or R.sup.1 and R.sup.2, taken together with the nitrogen atom to which each are attached, can form a heterocyclyl group, as defined herein); (5) aryl (e.g., C.sub.4-18 aryl); (6) arylalkoxy (e.g., O-L-R, in which L is C.sub.1-6 alkylene and R is C.sub.4-18 aryl); (7) aryloyl (e.g., C(O)R, in which R is C.sub.4-18 aryl); (8) azido (e.g., N.sub.3); (9) cyano (e.g., CN); (10) aldehyde (e.g., C(O) H); (11) C.sub.3-8 cycloalkyl; (12) halo; (13) heterocyclyl (e.g., as defined herein, such as a 5-, 6- or 7-membered ring containing one, two, three, or four non-carbon heteroatoms); (14) heterocyclyloxy (e.g., OR, in which R is heterocyclyl, as defined herein); (15) heterocyclyloyl (e.g., C(O)R, in which R is heterocyclyl, as defined herein); (16) hydroxy (e.g., OH); (17) N-protected amino; (18) nitro (e.g., NO.sub.2); (19) oxo (e.g., O); (20) C.sub.1-6 thioalkoxy (e.g., SR, in which R is alkyl); (21) thiol (e.g., SH); (22) CO.sub.2R.sup.1, where R.sup.1 is selected from the group consisting of (a) hydrogen, (b) C.sub.1-6 alkyl, (c) C.sub.4-18 aryl, and (d) C.sub.1-6 alkyl-C.sub.4-18 aryl (e.g., -L-R, in which L is C.sub.1-6 alkylene and R is C.sub.4-18 aryl); (23) C(O) NR.sup.1R.sup.2, where each of R.sup.1 and R.sup.2 is, independently, selected from the group consisting of (a) hydrogen, (b) C.sub.1-6 alkyl, (c) C.sub.4-18 aryl, and (d) C.sub.1-6 alkyl-C.sub.4-18 aryl (e.g., -L-R, in which L is C.sub.1-6 alkylene and R is C.sub.4-18 aryl); (24) SO.sub.2R.sup.1, where R.sup.1 is selected from the group consisting of (a) C.sub.1-6 alkyl, (b) C.sub.4-18 aryl, and (c) C.sub.1-6 alkyl-C.sub.4-18 aryl (e.g., -L-R, in which L is C.sub.1-6 alkylene and R is C.sub.4-18 aryl); (25) SO.sub.2NR.sup.1R.sup.2, where each of R.sup.1 and R.sup.2 is, independently, selected from the group consisting of (a) hydrogen, (b) C.sub.1-6 alkyl, (c) C.sub.4-18 aryl, and (d) C.sub.1-6 alkyl-C.sub.4-18 aryl (e.g., -L-R, in which L is C.sub.1-6 alkylene and R is C.sub.4-18 aryl); and (26) NR.sup.1R.sup.2, where each of R.sup.1 and R.sup.2 is, independently, selected from the group consisting of (a) hydrogen, (b) an N-protecting group, (c) C.sub.1-6 alkyl, (d) C.sub.2-6 alkenyl, (e) C.sub.2-6 alkynyl, (f) C.sub.4-18 aryl, (g) C.sub.1-6 alkyl-C.sub.4-18 aryl (e.g., -L-R, in which L is C.sub.1-6 alkylene and R is C.sub.4-18 aryl), (h) C.sub.3-8 cycloalkyl, and (i) C.sub.1-6 alkyl-C.sub.3-8 cycloalkyl (e.g., -L-R, in which L is C.sub.1-6 alkylene and R is C.sub.3-8 cycloalkyl), where in one embodiment no two groups are bound to the nitrogen atom through a carbonyl group or a sulfonyl group.

    [0382] In some embodiments, the alkyl group is a primary, secondary, or tertiary alkyl group substituted with one or more substituents (e.g., one or more halo or alkoxy). In some embodiments, the unsubstituted alkyl group is a C.sub.1-3, C.sub.1-4, C.sub.1-6, C.sub.1-8, C.sub.1-10, C.sub.1-12, C.sub.1-16, C.sub.1-18, C.sub.1-20, C.sub.1-24, C.sub.2-6, C.sub.2-8, C.sub.2-10, C.sub.2-12, C.sub.2-16, C.sub.2-18, C.sub.2-20, C.sub.2-24, C.sub.3-8, C.sub.3-10, C.sub.3-12, C.sub.3-16, C.sub.3-18, C.sub.3-20, or C.sub.3-24 alkyl group. Unless stated otherwise specifically in the specification, an alkyl group is optionally substituted by one or more of substituents that are independently heteroalkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, hydroxy, halo, cyano, trifluoromethyl, trifluoromethoxy, nitro, trimethylsilanyl, OR.sup.a, SR.sup.a, OC(O)R.sup.a, N(R.sup.a).sub.2, C(O) R.sup.a, C(O) OR.sup.a, OC(O) N(R.sup.a).sub.2, C(O) N(R.sup.a).sub.2, N(R.sup.a) C(O) OR.sup.a, N(R.sup.a) C(O) R.sup.a, N(R.sup.a) C(O) N(R.sup.a).sub.2, N(R.sup.a)C(NR.sup.a) N(R.sup.a).sub.2, N(R.sup.a)S(O)(R.sup.a (where t is 1 or 2), S(O).sub.tR.sup.a (where t is 1 or 2), S(O)OR.sup.a (where t is 1 or 2), S(O).sub.tN(R.sup.a).sub.2 (where t is 1 or 2), or PO.sub.3(R.sup.a).sub.2 where each R.sup.a is independently hydrogen, fluoroalkyl, carbocyclyl, carbocyclylalkyl, aryl, aralkyl, heterocycloalkyl, heterocycloalkylalkyl, heteroaryl or heteroarylalkyl.

    [0383] By alkylene is meant a multivalent (e.g., bivalent) form of an aliphatic or alkyl group, as described herein. Exemplary alkylene groups include methylene, ethylene, propylene, butylene, etc. In some embodiments, the alkylene group is a C.sub.1-3, C.sub.1-4, C.sub.1-6, C.sub.1-12, C.sub.1-16, C.sub.1-18, C.sub.1-20, C.sub.1-24, C.sub.2-3, C.sub.2-6, C.sub.2-12, C.sub.2-16, C.sub.2-18, C.sub.2-20, or C.sub.2-24 alkylene group. In some embodiments, the alkylene group is branched or unbranched. The alkylene group is also substituted or unsubstituted. For example, in some embodiments, the alkylene group is substituted with one or more substitution groups, as described herein for alkyl.

    [0384] The term alkoxy refers to the group-O-alkyl, including from 1 to 24 carbon atoms of a straight, branched, cyclic configuration and combinations thereof attached to the parent structure through an oxygen. Exemplary alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, cyclopropyloxy, butoxy, cyclohexyloxy, and trihaloalkoxy, such as trifluoromethoxy, etc. In some embodiments, the alkoxy group is substituted or unsubstituted. For example, in some embodiments, the alkoxy group is substituted with one or more substitution groups, as described herein for alkyl. Exemplary unsubstituted alkoxy groups include C.sub.1-3, C.sub.1-6, C.sub.1-12, C.sub.1-16, C.sub.1-18, C.sub.1-20, or C.sub.1-24 alkoxy groups.

    [0385] The term substituted alkoxy refers to alkoxy where the alkyl constituent is substituted (e.g., O-(substituted alkyl)). Unless stated otherwise specifically in the specification, the alkyl moiety of an alkoxy group is optionally substituted by one or more substituents the independently are: alkyl, heteroalkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, hydroxy, halo, cyano, trifluoromethyl, trifluoromethoxy, nitro, trimethylsilanyl, OR.sup.a, SR.sup.a, OC(O)R.sup.a, N(R.sup.a).sub.2, C(O) R.sup.a, C(O) OR.sup.a, OC(O) N(R.sup.a).sub.2, C(O) N(R.sup.a).sub.2, N(R.sup.a) C(O) OR.sup.a, N(R.sup.a) C(O) R.sup.a, N(R.sup.a) C(O) N(R.sup.a).sub.2, N(R.sup.a)C(NR.sup.a) N(R.sup.a).sub.2, N(R.sup.a)S(O); R.sup.a (where t is 1 or 2), S(O),R.sup.a (where t is 1 or 2), S(O),OR.sup.a (where t is 1 or 2), S(O).sub.tN(R.sup.a).sub.2 (where t is 1 or 2), or PO.sub.3(R.sup.a).sub.2, where each R.sup.a is independently hydrogen, alkyl, fluoroalkyl, carbocyclyl, carbocyclylalkyl, aryl, aralkyl, heterocycloalkyl, heterocycloalkylalkyl, heteroaryl or heteroarylalkyl.

    [0386] The term alkylsilyl, as used herein, refers to SiR.sup.1R.sup.2R.sup.3 group, where R.sup.1 is an optionally substituted alkyl, and where each of R.sup.2 and R.sup.3 is independently selected from H and an optionally substituted alkyl. Alkylsilyls include mono, bis, and tris alkylsilyls. Examples of alkylsilyls include trimethylsilyl, dimethylsilyl, methylsilyl, triethylsilyl, diethylsilyl, ethylsilyl, and the like.

    [0387] By alkylsulfinyl is meant an alkyl group, as defined herein, attached to the parent molecular group through an S(O)-group. In some embodiments, the unsubstituted alkylsulfinyl group is a C.sub.1-6 or C.sub.1-12 alkylsulfinyl group. In other embodiments, the alkylsulfinyl group is S(O)R, in which R is an alkyl group, as defined herein.

    [0388] By alkylsulfinylalkyl is meant an alkyl group, as defined herein, substituted by an alkylsulfinyl group. In some embodiments, the unsubstituted alkylsulfinylalkyl group is a C.sub.2-12 or C.sub.2-24 alkylsulfinylalkyl group (e.g., C.sub.1-6 alkylsulfinyl-C.sub.1-6 alkyl or C.sub.1-12 alkylsulfinyl-C.sub.1-12 alkyl). In other embodiments, the alkylsulfinylalkyl group is -L-S(O)R, in which L is alkylene, as defined herein, and R is an alkyl group, as defined herein.

    [0389] By alkylsulfonyl is meant an alkyl group, as defined herein, attached to the parent molecular group through an SO.sub.2-group. In some embodiments, the unsubstituted alkylsulfonyl group is a C.sub.1-6 or C.sub.1-12 alkylsulfonyl group. In other embodiments, the alkylsulfonyl group is SO.sub.2R, where R is an optionally substituted alkyl (e.g., as described herein, including optionally substituted C.sub.1-12 alkyl, haloalkyl, or perfluoroalkyl).

    [0390] By alkylsulfonylalkyl is meant an alkyl group, as defined herein, substituted by an alkylsulfonyl group. In some embodiments, the unsubstituted alkylsulfonylalkyl group is a C.sub.2-12 or C.sub.2-24 alkylsulfonylalkyl group (e.g., C.sub.1-6 alkylsulfonyl-C.sub.1-6 alkyl or C.sub.1-12 alkylsulfonyl-C.sub.1-12 alkyl). In other embodiments, the alkylsulfonylalkyl group is -L-SO.sub.2R, in which L is alkylene, as defined herein, and R is an alkyl group, as defined herein.

    [0391] By alkynyl is meant an optionally substituted C.sub.2-24 alkyl group having one or more triple bonds. The alkynyl group can be cyclic or acyclic and is exemplified by ethynyl, 1-propynyl, and the like. The alkynyl group can also be substituted or unsubstituted. For example, the alkynyl group can be substituted with one or more substitution groups, as described herein for alkyl. Non-limiting unsubstituted alkynyl groups include C.sub.2-8 alkynyl, C.sub.2-6 alkynyl, C.sub.2-5 alkynyl, C.sub.2-4 alkynyl, or C.sub.2-3 alkynyl. Non-limiting examples of alkynyl groups include ethynyl (CCH), 1-propynyl (CCCH.sub.3), 2-propynyl or propargyl (CH.sub.2CCH), 1-butynyl (CCCH.sub.2CH.sub.3), 2-butynyl (CH.sub.2CCCH.sub.3), 3-butynyl (CH.sub.2CH.sub.2CCH), and the like. In some embodiments, the unsubstituted alkynyl group is a C.sub.2-6, C.sub.2-8, C.sub.2-10, C.sub.2-12, C.sub.2-16, C.sub.2-18, C.sub.2-20, C.sub.2-24, C.sub.3-8, C.sub.3-10, C.sub.3-12, C.sub.3-16, C.sub.3-18, C.sub.3-20, or C.sub.3-24 alkynyl group.

    [0392] By alkynylene is meant a multivalent (e.g., bivalent) form of an alkynyl group, which is an optionally substituted C.sub.2-24 alkyl group having one or more triple bonds. The alkynylene group can be cyclic or acyclic. The alkynylene group can be substituted or unsubstituted. For example, the alkynylene group can be substituted with one or more substitution groups, as described herein for alkyl. Non-limiting examples of alkynylene groups include CC or CCCH.sub.2.

    [0393] By amido is meant-C(O) NR.sup.1R.sup.2 or NHCOR.sup.1, where each of R.sup.1 and R.sup.2 is, independently, selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof, or where R.sup.1 and R.sup.2, taken together with the nitrogen atom to which each are attached, can form a heterocyclyl group, as defined herein.

    [0394] By amine or amino is meant a NR.sup.N1R.sup.N2 group, a NR.sup.N1-group, or a compound having such a group, where each of R.sup.N1 and R.sup.N2 is, independently, H, optionally substituted aliphatic, alkyl, hydroxyalkyl, heteroaliphatic, heteroalkyl, aromatic, or aryl; or where R.sup.N1 and R.sup.N2, taken together with the nitrogen atom to which each are attached, form a heterocyclyl group, as defined herein. In some embodiments an amino or amino is meant a N(R.sup.a).sub.2 radical group, where each R.sup.a is independently hydrogen, alkyl, fluoroalkyl, carbocyclyl, carbocyclylalkyl, aryl, aralkyl, heterocycloalkyl, heterocycloalkylalkyl, heteroaryl or heteroarylalkyl, unless stated otherwise specifically in the specification. When a N(R.sup.a).sub.2 group has two R.sup.a substituents other than hydrogen, they can be combined with the nitrogen atom to form a 4-, 5-, 6- or 7-membered ring. For example, N(R.sup.a).sub.2 is intended to include, but is not limited to, 1-pyrrolidinyl and 4-morpholinyl. Unless stated otherwise specifically in the specification, an amino group is optionally substituted by one or more substituents which independently are: alkyl, heteroalkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, hydroxy, halo, cyano, trifluoromethyl, trifluoromethoxy, nitro, trimethylsilanyl, OR.sup.a, SR.sup.a, OC(O)R.sup.a, N(R.sup.a).sub.2, C(O) R.sup.a, C(O) OR.sup.a, OC(O) N(R.sup.a).sub.2, C(O) N(R.sup.a).sub.2, N(R.sup.a) C(O) OR.sup.a, N(R.sup.a) C(O) R.sup.a, N(R.sup.a) C(O) N(R.sup.a).sub.2, N(R.sup.a)C(NR.sup.a) N(R.sup.a).sub.2, N(R.sup.a)S(O); R.sup.a (where t is 1 or 2), S(O).sub.tR.sup.a (where t is 1 or 2), S(O),OR.sup.a (where t is 1 or 2), S(O).sub.tN(R.sup.a).sub.2 (where t is 1 or 2), or PO.sub.3(R.sup.a).sub.2, where each R.sup.a is independently hydrogen, alkyl, fluoroalkyl, carbocyclyl, carbocyclylalkyl, aryl, aralkyl, heterocycloalkyl, heterocycloalkylalkyl, heteroaryl or heteroarylalkyl.

    [0395] The term substituted amino also refers to N-oxides of the groupsNHR.sup.a, and NR.sup.aR.sup.a each as described above. N-oxides can be prepared by treatment of the corresponding amino group with, for example, hydrogen peroxide or m-chloroperoxybenzoic acid.

    [0396] By aminoalkyl is meant an aliphatic or alkyl group, as described herein, substituted with one, two, three, or more amine groups. In some embodiments the aminoalkyl includes internal amine groups or terminal amine groups. In some embodiments, the aminoalkyl group is further substituted. For example, in some embodiments, the aminoalkyl group is substituted with one or more substitution groups, as described herein for alkyl. Exemplary unsubstituted aminoalkyl groups include C.sub.1-3, C.sub.1-6, C.sub.1-12, C.sub.1-16, C.sub.1-18, C.sub.1-20, or C.sub.1-24 aminoalkyl groups. In some embodiments, the aminoalkyl group is -L-NR.sup.1R.sup.2, in which L is an aliphatic or alkylene group, as defined herein, and each of R.sup.1 and R.sup.2 is, independently, selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof; or R.sup.1 and R.sup.2, taken together with the nitrogen atom to which each are attached, can form a heterocyclyl group, as defined herein. In other embodiments, the aminoalkyl group is -L-C(NR.sup.1R.sup.2)(R.sub.3)R.sub.4, in which L is a covalent bond, an aliphatic group, or an alkylene group, as defined herein; each of R.sup.1 and R.sup.2 is, independently, selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof; or R.sup.1 and R.sup.2, taken together with the nitrogen atom to which each are attached, can form a heterocyclyl group, as defined herein; and each of R.sub.3 and R.sub.4 is, independently, H or alkyl, as defined herein.

    [0397] By aminoaryl is meant an aromatic or aryl group, as defined herein, substituted by an amino group, as defined herein.

    [0398] By aromatic is meant a cyclic, conjugated group or moiety of, unless specified otherwise, from 5 to 15 ring atoms having a single ring (e.g., phenyl) or multiple condensed rings in which at least one ring is aromatic (e.g., naphthyl, indolyl, or pyrazolopyridinyl); that is, at least one ring, and optionally multiple condensed rings, have a continuous, delocalized T-electron system. Typically, the number of out of plane x-electrons corresponds to the Huckel rule (4n+2). The point of attachment to the parent structure typically is through an aromatic portion of the condensed ring system.

    [0399] By aryl is meant an aromatic carbocyclic group comprising at least five carbon atoms to 15 carbon atoms (C.sub.5-15), such as five to ten carbon atoms (C.sub.5-10), having a single ring or multiple condensed rings, which condensed rings can or may not be aromatic provided that the point of attachment to a remaining position of the compounds disclosed herein is through an atom of the aromatic carbocyclic group. Aryl groups may be substituted with one or more groups other than hydrogen, such as alkyl, as well as any substitution groups described herein for alkyl. Non-limiting examples of aryl groups include, but are not limited to, benzyl, naphthalene, phenyl, biphenyl, phenoxybenzene, and the like. The term aryl also includes heteroaryl, which is defined as a group that contains an aromatic group that has at least one heteroatom incorporated within the ring of the aromatic group. Examples of heteroatoms include, but are not limited to, nitrogen, oxygen, sulfur, and phosphorus. Likewise, the term non-heteroaryl, which is also included in the term aryl, defines a group that contains an aromatic group that does not contain a heteroatom. The aryl group can be substituted with one, two, three, four, or five substituents provided herein for alkyl. In particular embodiments, an unsubstituted aryl group is a C.sub.4-18, C.sub.4-14, C.sub.4-12, C.sub.4-10, C.sub.6-18, C.sub.6-14, C.sub.6-12, or C.sub.6-10 aryl group. Aryl groups can have any suitable number of carbon ring atoms and any suitable number of rings. Aryl groups can include any suitable number of carbon ring atoms, such as C.sub.6, C.sub.7, C.sub.8, C.sub.9, C.sub.10, C.sub.11, C.sub.12, C.sub.13, C.sub.14, C.sub.15 or C.sub.16, as well as C.sub.6-12, C.sub.6-10, or C.sub.6-14. Bivalent radicals formed from substituted benzene derivatives and having the free valences at ring atoms are named as substituted phenylene radicals. Bivalent radicals derived from univalent polycyclic hydrocarbon radicals whose names end in -yl by removal of one hydrogen atom from the carbon atom with the free valence are named by adding -idene to the name of the corresponding univalent radical, e.g., a naphthyl group with two points of attachment is termed naphthylidene. Whenever it appears herein, a numerical range such as 6 to 10 (e.g., C.sub.6-C.sub.10 aromatic or C.sub.6-C.sub.10 aryl) refers to each integer in the given range; e.g., 6 to 10 ring atoms means that the aryl group may consist of 6 ring atoms, 7 ring atoms, etc., up to and including 10 ring atoms. Aryl groups can be monocyclic, fused (i.e., rings which share adjacent pairs of ring atoms) to form bicyclic (e.g., benzocyclohexyl) or tricyclic groups or polycyclic groups, or linked by a bond to form a biaryl group. Representative aryl groups include phenyl, naphthyl and biphenyl. Other aryl groups include benzyl, having a methylene linking group. Unless stated otherwise specifically in the specification, an aryl moiety is optionally substituted by one or more substituents which are independently alkyl, heteroalkyl, acylsulfonamido, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, hydroxamate, aryl, arylalkyl, heteroaryl, heteroarylalkyl, hydroxy, halo, cyano, trifluoromethyl, trifluoromethoxy, nitro, trimethylsilanyl, OR.sup.a, SR.sup.a, S(O).sub.tR.sup.a-(where t is 1 or 2), OC(O)R.sup.a, N(R.sup.a).sub.2, C(O) R.sup.a, C(O) OR.sup.a, OC(O) N(R.sup.a).sub.2, C(O) N(R.sup.a).sub.2, N(R.sup.a) C(O) OR.sup.a, N(R.sup.a) C(O) R.sup.a, N(R.sup.a) C(O) N(R.sup.a).sub.2, N(R.sup.a)C(NR.sup.a) N(R.sup.a).sub.2, N(R.sup.a)S(O).sub.tR.sup.a (where t is 1 or 2), S(O).sub.tR.sup.a (where t is 1 or 2), S(O); OR.sup.a (where t is 1 or 2), S(O).sub.tN(R.sup.a).sub.2 (where t is 1 or 2), or PO(OR.sup.a).sub.2, where each R.sup.a is independently hydrogen, alkyl, fluoroalkyl, carbocyclyl, carbocyclylalkyl, aryl, aralkyl, heterocycloalkyl, heterocycloalkylalkyl, heteroaryl or heteroarylalkyl.

    [0400] By arylene is meant a multivalent (e.g., bivalent) form of an aromatic or aryl group, as described herein. Exemplary arylene groups include phenylene, naphthylene, biphenylene, triphenylene, diphenyl ether, acenaphthenylene, anthrylene, or phenanthrylene. In some embodiments, the arylene group is a C.sub.4-18, C.sub.4-14, C.sub.4-12, C.sub.4-10, C.sub.6-18, C.sub.6-14, C.sub.6-12, or C.sub.6-10 arylene group. In some embodiments, the arylene group is branched or unbranched. In some embodiments, the arylene group is further substituted or unsubstituted. For example, In some embodiments, the arylene group is substituted with one or more substitution groups, as described herein for alkyl or aryl.

    [0401] By aryloxy is meant-OR, where R is an optionally substituted aromatic or aryl group, as described herein. In some embodiments, an unsubstituted aryloxy group is a C.sub.4-18 or C.sub.6-18 aryloxy group.

    [0402] By arylalkoxy is meant an alkyl-aryl group, as defined herein, attached to the parent molecular group through an oxygen atom. In some embodiments, the arylalkoxy group is O-L-R, in which L is an alkylene group, as defined herein, and R is an aryl group, as defined herein.

    [0403] By aryloxycarbonyl is meant an aryloxy group, as defined herein, that is attached to the parent molecular group through a carbonyl group. In some embodiments, an unsubstituted aryloxycarbonyl group is a C.sub.5-19 aryloxycarbonyl group. In other embodiments, the aryloxycarbonyl group is C(O)OR, in which R is an aryl group, as defined herein.

    [0404] By aryloyl is meant an aryl group that is attached to the parent molecular group through a carbonyl group. In some embodiments, an unsubstituted aryloyl group is a C.sub.7-11 aryloyl or C.sub.5-19 aryloyl group. In other embodiments, the aryloyl group is C(O)R, in which R is an aryl group, as defined herein.

    [0405] By (aryl) (alkyl) ene is meant a bivalent form including an arylene group, as described herein, attached to an alkylene or a heteroalkylene group, as described herein. In some embodiments, the (aryl) (alkyl) ene group is -L-Ar or -L- Ar-L- or Ar-L-, in which Ar is an aromatic or arylene group and each L is, independently, an optionally substituted aliphatic, alkylene group, heteroaliphatic, or heteroalkylene group.

    [0406] By borono is meant a B(OH).sub.2 group.

    [0407] By carbonyl is meant a C(O)-group, which can also be represented as >CO, or a CO-group.

    [0408] By carboxyl or carboxylic acid is meant a CO.sub.2H group or a compound including such a group, including deprotonated and protonated forms thereof.

    [0409] By carboxyalkyl is meant an alkyl group, as defined herein, substituted by one or more carboxyl groups, as defined herein.

    [0410] By carboxyaryl is meant an aryl group, as defined herein, substituted by one or more carboxyl groups, as defined herein.

    [0411] By cyclic anhydride is meant a 3-, 4-, 5-, 6- or 7-membered ring (e.g., a 5-, 6- or 7-membered ring), unless otherwise specified, having a C(O)OC(O)-group within the ring. The term cyclic anhydride also includes bicyclic, tricyclic, and tetracyclic groups in which any of the above rings is fused to one, two, or three rings independently selected from the group consisting of an aryl ring, a cyclohexane ring, a cyclohexene ring, a cyclopentane ring, a cyclopentene ring, and another monocyclic heterocyclic ring. Exemplary cyclic anhydride groups include a radical formed from succinic anhydride, glutaric anhydride, maleic anhydride, phthalic anhydride, isochroman -1,3-dione, oxepanedione, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, pyromellitic dianhydride, naphthalic anhydride, 1,2-cyclohexanedicarboxylic anhydride, etc., by removing one or more hydrogen. Other exemplary cyclic anhydride groups include dioxotetrahydrofuranyl, dioxodihydroisobenzofuranyl, etc. The cyclic anhydride group can also be substituted or unsubstituted. For example, the cyclic anhydride group can be substituted with one or more groups including those described herein for heterocyclyl.

    [0412] By cycloaliphatic is meant an aliphatic group, as defined herein, that is cyclic.

    [0413] By cycloalkoxy is meant a cycloalkyl group, as defined herein, attached to the parent molecular group through an oxygen atom. In some embodiments, the cycloalkoxy group is OR, in which R is a cycloalkyl group, as defined herein.

    [0414] By cycloalkylalkoxy is meant an alkyl-cycloalkyl group, as defined herein, attached to the parent molecular group through an oxygen atom. In some embodiments, the cycloalkylalkoxy group is O-L-R, in which L is an alkylene group, as defined herein, and R is a cycloalkyl group, as defined herein.

    [0415] By cycloalkyl is meant a monovalent saturated or unsaturated non-aromatic cyclic hydrocarbon group of from three to eight carbons, unless otherwise specified, and is exemplified by cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, bicyclo[2.2.1.heptyl], and the like. The cycloalkyl group can also be substituted or unsubstituted. For example, the cycloalkyl group can be substituted with one or more groups including those described herein for alkyl.

    [0416] By cycloheteroaliphatic is meant a heteroaliphatic group, as defined herein, that is cyclic.

    [0417] By disulfide is meant-SSR, where R is selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, as defined herein, or any combination thereof.

    [0418] By formyl is meant a C(O)H group.

    [0419] By halo is meant F, Cl, Br, or I.

    [0420] By haloaliphatic is meant an aliphatic group, as defined herein, substituted with one or more halo.

    [0421] By haloalkyl is meant an alkyl group, as defined herein, substituted with one or more halo.

    [0422] By haloalkenyl is meant an alkenyl group, as defined herein, substituted with one or more halo.

    [0423] By haloalkynyl is meant an alkynyl group, as defined herein, substituted with one or more halo.

    [0424] By haloalkylene is meant an alkylene group, as defined herein, substituted with one or more halo.

    [0425] By halocarbonyl is meant a C(O) X group, in which X is halo, as defined herein.

    [0426] By haloheteroaliphatic is meant a heteroaliphatic, as defined herein, in which one or more hydrogen atoms, such as one to 10 hydrogen atoms, independently is replaced with a halogen atom, such as fluoro, bromo, chloro, or iodo.

    [0427] By heteroaliphatic is meant an aliphatic group, as defined herein, including at least one heteroatom to 20 heteroatoms, such as one to 15 heteroatoms, or one to 5 heteroatoms, which can be selected from, but not limited to boron, halo, nitrogen, oxygen, phosphorus, selenium, silicon, sulfur, and, if applicable, oxidized forms thereof within the group.

    [0428] By heteroalkyl, heteroalkenyl, and heteroalkynyl is meant an alkyl, alkenyl, or alkynyl group (which can be branched, straight-chain, or cyclic), respectively, as defined herein, including at least one heteroatom to 20 heteroatoms, such as one to 15 heteroatoms, or one to 5 heteroatoms, which can be selected from, but not limited to, boron, halo, nitrogen (e.g., as present in imino), oxygen, phosphorus, selenium, silicon, sulfur, and, if applicable, oxidized forms thereof within the group.

    [0429] By heteroalkylene is meant a multivalent (e.g., bivalent) form of a heteroaliphatic or heteroalkyl group, as described herein. The heteroalkylene group can be substituted or unsubstituted. For example, in some embodiments the heteroalkylene group is substituted with one or more substitution groups, as described herein for alkyl.

    [0430] By heteroalkenylene is meant a multivalent (e.g., bivalent) form of a heteroalkenyl group, which is an optionally substituted heteroalkyl group having one or more double bonds. The heteroalkenylene group can be cyclic or acyclic. The heteroalkenylene group can be substituted or unsubstituted. For example, the heteroalkenylene group can be substituted with one or more substitution groups, as described herein for alkyl.

    [0431] By heteroalkynylene is meant a multivalent (e.g., bivalent) form of a heteroalkynyl group, which is an optionally substituted heteroalkyl group having one or more triple bonds. The heteroalkynylene group can be cyclic or acyclic. The heteroalkynylene group can be substituted or unsubstituted. For example, the heteroalkynylene group can be substituted with one or more substitution groups, as described herein for alkyl.

    [0432] By heteroaromatic is meant an aromatic group, as defined herein, including at least one heteroatom to 20 heteroatoms, such as one to 15 heteroatoms, or one to 5 heteroatoms, which can be selected from, but not limited to boron, nitrogen, oxygen, phosphorus, selenium, silicon, sulfur, and oxidized forms thereof within the group.

    [0433] By heteroaryl is meant an aryl group including at least one heteroatom to six heteroatoms, such as one to four heteroatoms, which can be selected from, but not limited to, boron, nitrogen, oxygen, phosphorus, selenium, silicon, sulfur, and oxidized forms thereof within the ring. Such heteroaryl groups can have a single ring or multiple condensed rings, where the condensed rings may or may not be aromatic or may contain a heteroatom, provided that the point of attachment is through an atom of the aromatic heteroaryl group. Heteroaryl groups may be substituted with one or more groups other than hydrogen, such as alkyl, as well as any substitution groups described herein for alkyl. A non-limiting example of heteroaryl includes a subset of heterocyclyl groups, as defined herein, which are aromatic, e.g., they contain 4n+2 pi electrons within the mono- or multicyclic ring system.

    [0434] By heteroarylene is meant a multivalent (e.g., bivalent) form of a heteroaromatic or heteroaryl group, as described herein. Exemplary heteroarylene groups include pyridinylene and the like. In some embodiments, the heteroarylene group is a C.sub.4-18, C.sub.4-14, C.sub.4-12, C.sub.4-10, C.sub.6-18, C.sub.6-14, C.sub.6-12, or C.sub.6-10 heteroarylene group. In some embodiments, the heteroarylene group is branched or unbranched. In some embodiments, the heteroarylene group is further substituted or unsubstituted. For example, in some embodiments, the heteroarylene group is substituted with one or more substitution groups, as described herein for alkyl or aryl.

    [0435] By heterocyclyl is meant a 3-, 4-, 5-, 6- or 7-membered ring (e.g., a 5-, 6- or 7-membered ring), unless otherwise specified, containing one, two, three, or four non-carbon heteroatoms (e.g., independently selected from the group consisting of nitrogen, oxygen, phosphorus, selenium, silicon, or sulfur). The 3-membered ring has zero to one double bonds, the 4- and 5-membered ring has zero to two double bonds, and the 6- and 7-membered rings have zero to three double bonds. The term heterocyclyl also includes bicyclic, tricyclic, tetracyclic, or other multicyclic groups. Heterocyclics include acridinyl, adenyl, alloxazinyl, azaadamantanyl, azabenzimidazolyl, azabicyclononyl, azacycloheptyl, azacyclooctyl, azacyclononyl, azahypoxanthinyl, azaindazolyl, azaindolyl, azecinyl, azepanyl, azepinyl, azetidinyl, azetyl, aziridinyl, azirinyl, azocanyl, azocinyl, azonanyl, benzimidazolyl, benzisothiazolyl, benzisoxazolyl, benzodiazepinyl, benzodiazocinyl, benzodihydrofuryl, benzodioxepinyl, benzodioxinyl, benzodioxanyl, benzodioxocinyl, benzodioxolyl, benzodithiepinyl, benzodithiinyl, benzodioxocinyl, benzofuranyl, benzophenazinyl, benzopyranonyl, benzopyranyl, benzopyrenyl, benzopyronyl, benzoquinolinyl, benzoquinolizinyl, benzothiadiazepinyl, benzothiadiazolyl, benzothiazepinyl, benzothiazocinyl, benzothiazolyl, benzothienyl, benzothiophenyl, benzothiazinonyl, benzothiazinyl, benzothiopyranyl, benzothiopyronyl, benzotriazepinyl, benzotriazinonyl, benzotriazinyl, benzotriazolyl, benzoxathiinyl, benzotrioxepinyl, benzoxadiazepinyl, benzoxathiazepinyl, benzoxathiepinyl, benzoxathiocinyl, benzoxazepinyl, benzoxazinyl, benzoxazocinyl, benzoxazolinonyl, benzoxazolinyl, benzoxazolyl, benzylsultamyl, benzylsultimyl, bipyrazinyl, bipyridinyl, carbazolyl (e.g., 4H-carbazolyl), carbolinyl (e.g., -carbolinyl), chromanonyl, chromanyl, chromenyl, cinnolinyl, coumarinyl, cytdinyl, cytosinyl, decahydroisoquinolinyl, decahydroquinolinyl, diazabicyclooctyl, diazetyl, diaziridinethionyl, diaziridinonyl, diaziridinyl, diazirinyl, dibenzisoquinolinyl, dibenzoacridinyl, dibenzocarbazolyl, dibenzofuranyl, dibenzophenazinyl, dibenzopyranonyl, dibenzopyronyl (xanthonyl), dibenzoquinoxalinyl, dibenzothiazepinyl, dibenzothiepinyl, dibenzothiophenyl, dibenzoxepinyl, dihydroazepinyl, dihydroazetyl, dihydrofuranyl, dihydrofuryl, dihydroisoquinolinyl, dihydropyranyl, dihydropyridinyl, dihydroypyridyl, dihydroquinolinyl, dihydrothienyl, dihydroindolyl, dioxanyl, dioxazinyl, dioxindolyl, dioxiranyl, dioxenyl, dioxinyl, dioxobenzofuranyl, dioxolyl, dioxooxolanyl, dioxotetrahydrofuranyl, dioxothiomorpholinyl, dithianyl, dithiazolyl, dithienyl, dithiinyl, furanyl, furazanyl, furoyl, furyl, guaninyl, homopiperazinyl, homopiperidinyl, hypoxanthinyl, hydantoinyl, imidazolidinyl, imidazolinyl, imidazolyl, indazolyl (e.g., 1H-indazolyl), indolenyl, indolinyl, indolizinyl, indolyl (e.g., 1H-indolyl or 3H-indolyl), isatinyl, isatyl, isobenzofuranyl, isochromanyl, isochromenyl, isoindazoyl, isoindolinyl, isoindolyl, isopyrazolonyl, isopyrazolyl, isoxazolidiniyl, isoxazolyl, isoquinolinyl, isoquinolinyl, isothiazolidinyl, isothiazolyl, morpholinyl, naphthindazolyl, naphthindolyl, naphthiridinyl, naphthopyranyl, naphthothiazolyl, naphthothioxolyl, naphthotriazolyl, naphthoxindolyl, naphthyridinyl, octahydroisoquinolinyl, oxabicycloheptyl, oxauracil, oxadiazolyl, oxazinyl, oxaziridinyl, oxazolidinyl, oxazolidonyl, oxazolinyl, oxazolonyl, oxazolyl, oxepanyl, oxetanonyl, oxetanyl, oxetyl, oxtenayl, oxindolyl, oxiranyl, oxobenzoisothiazolyl, oxochromenyl, oxoisoquinolinyl, oxolanyl, oxoquinolinyl, oxothiolanyl, phenanthridinyl, phenanthrolinyl, phenazinyl, phenothiazinyl, phenothienyl (benzothiofuranyl), phenoxathiinyl, phenoxazinyl, phthalazinyl, phthalazonyl, phthalidyl, phthalimidinyl, piperazinyl, piperidinyl, piperidonyl (e.g., 4-piperidonyl), pteridinyl, purinyl, pyranyl, pyrazinyl, pyrazolidinyl, pyrazolinyl, pyrazolopyrimidinyl, pyrazolyl, pyridazinyl, pyridinyl, pyridopyrazinyl, pyridopyrimidinyl, pyridyl, pyrimidinyl, pyrimidyl, pyronyl, pyrrolidinyl, pyrrolidonyl (e.g., 2-pyrrolidonyl), pyrrolinyl, pyrrolizidinyl, pyrrolyl (e.g., 2H-pyrrolyl), pyrylium, quinazolinyl, quinolinyl, quinolizinyl (e.g., 4H-quinolizinyl), quinoxalinyl, quinuclidinyl, selenazinyl, selenazolyl, selenophenyl, succinimidyl, sulfolanyl, tetrahydrofuranyl, tetrahydrofuryl, tetrahydroisoquinolinyl, tetrahydroisoquinolyl, tetrahydropyridinyl, tetrahydropyridyl (piperidyl), tetrahydropyranyl, tetrahydropyronyl, tetrahydroquinolinyl, tetrahydroquinolyl, tetrahydrothienyl, tetrahydrothiophenyl, tetrazinyl, tetrazolyl, thiadiazinyl (e.g., 6H-1,2,5-thiadiazinyl or 2H,6H-1,5,2-dithiazinyl), thiadiazolyl, thianthrenyl, thianyl, thianaphthenyl, thiazepinyl, thiazinyl, thiazolidinedionyl, thiazolidinyl, thiazolyl, thienyl, thiepanyl, thiepinyl, thietanyl, thietyl, thiiranyl, thiocanyl, thiochromanonyl, thiochromanyl, thiochromenyl, thiodiazinyl, thiodiazolyl, thioindoxyl, thiomorpholinyl, thiophenyl, thiopyranyl, thiopyronyl, thiotriazolyl, thiourazolyl, thioxanyl, thioxolyl, thymidinyl, thyminyl, triazinyl, triazolyl, trithianyl, urazinyl, urazolyl, uretidinyl, uretinyl, uricyl, uridinyl, xanthenyl, xanthinyl, xanthionyl, and the like, as well as modified forms thereof (e.g., including one or more oxo and/or amino) and salts thereof. The heterocyclyl group can be substituted or unsubstituted. For example, the heterocyclyl group can be substituted with one or more substitution groups, as described herein for alkyl.

    [0436] By heterocyclyloxy is meant a heterocyclyl group, as defined herein, attached to the parent molecular group through an oxygen atom. In some embodiments, the heterocyclyloxy group is OR, in which R is a heterocyclyl group, as defined herein.

    [0437] By heterocyclyloyl is meant a heterocyclyl group, as defined herein, attached to the parent molecular group through a carbonyl group. In some embodiments, the heterocyclyloyl group is C(O)R, in which R is a heterocyclyl group, as defined herein. By hydroxy is meant-OH.

    [0438] By hydroxyalkyl is meant an alkyl group, as defined herein, substituted by one to three hydroxy groups, with the proviso that no more than one hydroxy group may be attached to a single carbon atom of the alkyl group and is exemplified by hydroxymethyl, dihydroxypropyl, and the like.

    [0439] By hydroxyaryl is meant an aryl group, as defined herein, substituted by one to three hydroxy groups, with the proviso that no more than one hydroxy group may be attached to a single carbon atom of the aryl group and is exemplified by hydroxyphenyl, dihydroxyphenyl, and the like.

    [0440] By imido is meant aNR group, where R is selected from H, aliphatic, alkyl, heteroaliphatic, heteroalkyl, aromatic, or aryl, as defined herein, or any combination thereof.

    [0441] By imino is meantNR, in which R can be H, optionally substituted aliphatic, alkyl, heteroaliphatic, heteroalkyl, aromatic, or aryl.

    [0442] By isocyanato is meant a NCO griyo.

    [0443] By nitro is meant anNO.sub.2 group.

    [0444] By nitroalkyl is meant an alkyl group, as defined herein, substituted by one to three nitro groups. In some embodiments, the nitroalkyl group is -L-NO, in which L is an alkylene group, as defined herein. In other embodiments, the nitroalkyl group is -L-C(NO)(R.sub.1)R.sub.2, in which L is a covalent bond or an alkylene group, as defined herein, and each of R.sup.1 and R.sup.2 is, independently, H or alkyl, as defined herein.

    [0445] By oxiranyl is meant a

    ##STR00043##

    group or a

    ##STR00044##

    group, in which one or more hydrogen atoms can be optionally substituted with another functional group (e.g., halo, alkyl, or any described herein as a substituent for alkyl).

    [0446] By oxo or oxide is meant an O group.

    [0447] By oxy is meant O.

    [0448] By phosphono or phosphonic acid is meant a P(O)(OH).sub.2 group or a compound including such a group, including deprotonated and protonated forms thereof.

    [0449] By perfluoroalkyl is meant an alkyl group, as defined herein, having each hydrogen atom substituted with a fluorine atom. Non-limiting examples of perfluoroalkyl groups include trifluoromethyl, pentafluoroethyl, etc. In some embodiments, the perfluoroalkyl group is (CF.sub.2).sub.nCF.sub.3, in which n is an integer from 0 to 20, 1 to 20, 1 to 18, 1 to 16, 1 to 14, 1 to 12, 1 to 10, 1 to 8, 2 to 20, 2 to 18, 2 to 16, 2 to 14, 2 to 12, 2 to 10, 2 to 8, and ranges therebetween.

    [0450] By perfluoroalkoxy is meant an alkoxy group, as defined herein, having each hydrogen atom substituted with a fluorine atom. In some embodiments, the perfluoroalkoxy group is OR, in which R is a perfluoroalkyl group, as defined herein.

    [0451] By salt is meant an ionic form of a compound or structure (e.g., any formulas, compounds, or compositions described herein), which includes a cation or anion compound to form an electrically neutral compound or structure. Salts are well known in the art. For example, non-toxic salts are described in Berge S. M. et al., Pharmaceutical salts, J. Pharm. Sci. 1977 January; 66 (1): 1-19; and in Handbook of Pharmaceutical Salts: Properties, Selection, and Use, Wiley-VCH, April 2011 (2nd rev. ed., eds. P. H. Stahl and C. G. Wermuth. The salts can be prepared in situ during the final isolation and purification of the compounds of the invention or separately by reacting the free base group with a suitable organic acid (thereby producing an anionic salt) or by reacting the acid group with a suitable metal or organic salt (thereby producing a cationic salt). Representative anionic salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bicarbonate, bisulfate, bitartrate, borate, bromide, butyrate, camphorate, camphorsulfonate, chloride, citrate, cyclopentanepropionate, digluconate, dihydrochloride, diphosphate, dodecylsulfate, edetate, ethanesulfonate, fumarate, glucoheptonate, gluconate, glutamate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, hydroxyethanesulfonate, hydroxynaphthoate, iodide, lactate, lactobionate, laurate, lauryl sulfate, malate, maleate, malonate, mandelate, mesylate, methanesulfonate, methylbromide, methylnitrate, methylsulfate, mucate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, polygalacturonate, propionate, salicylate, stearate, subacetate, succinate, sulfate, tannate, tartrate, theophyllinate, thiocyanate, triethiodide, toluenesulfonate, undecanoate, valerate salts, and the like. Representative cationic salts include metal salts, such as alkali or alkaline earth salts, e.g., barium, calcium (e.g., calcium edetate), lithium, magnesium, potassium, sodium, and the like; other metal salts, such as aluminum, bismuth, iron, and zinc; as well as nontoxic ammonium, quaternary ammonium, and amine cations, including, but not limited to ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, pyridinium, and the like. Other cationic salts include organic salts, such as chloroprocaine, choline, dibenzylethylenediamine, diethanolamine, ethylenediamine, methylglucamine, and procaine. Yet other salts include ammonium, sulfonium, sulfoxonium, phosphonium, iminium, imidazolium, benzimidazolium, amidinium, guanidinium, phosphazinium, phosphazenium, pyridinium, etc., as well as other cationic groups described herein (e.g., optionally substituted isoxazolium, optionally substituted oxazolium, optionally substituted thiazolium, optionally substituted pyrrolium, optionally substituted furanium, optionally substituted thiophenium, optionally substituted imidazolium, optionally substituted pyrazolium, optionally substituted isothiazolium, optionally substituted triazolium, optionally substituted tetrazolium, optionally substituted furazanium, optionally substituted pyridinium, optionally substituted pyrimidinium, optionally substituted pyrazinium, optionally substituted triazinium, optionally substituted tetrazinium, optionally substituted pyridazinium, optionally substituted oxazinium, optionally substituted pyrrolidinium, optionally substituted pyrazolidinium, optionally substituted imidazolinium, optionally substituted isoxazolidinium, optionally substituted oxazolidinium, optionally substituted piperazinium, optionally substituted piperidinium, optionally substituted morpholinium, optionally substituted azepanium, optionally substituted azepinium, optionally substituted indolium, optionally substituted isoindolium, optionally substituted indolizinium, optionally substituted indazolium, optionally substituted benzimidazolium, optionally substituted isoquinolinum, optionally substituted quinolizinium, optionally substituted dehydroquinolizinium, optionally substituted quinolinium, optionally substituted isoindolinium, optionally substituted benzimidazolinium, and optionally substituted purinium).

    [0452] By silane is meant-SiR.sup.S1R.sup.S2R.sup.S3, SiR.sup.S1R.sup.S2, or a compound having such groups, where each of R.sup.S1, R.sup.S2, and R.sup.S3 is, independently, H, optionally substituted aliphatic, alkyl, heteroaliphatic, heteroalkyl, aromatic, aryl, amine, or others described herein; or R.sup.S1 and R.sup.S2, taken together with the silicon atom to which each are attached, form a heterocyclyl group.

    [0453] By silyl ether is meant a functional group including a silicon atom covalently bound to an alkoxy group, as defined herein. In some embodiments, the silyl ether is SiOR or SiOR, in which R is an alkyl group, as defined herein.

    [0454] By sulfinyl is meant an S(O)-group.

    [0455] By sulfo or sulfonic acid is meant an S(O).sub.2OH group or a compound including such a group, including deprotonated and protonated forms thereof.

    [0456] By sulfonyl or sulfonate is meant an S(O).sub.2-group or a SO.sub.2R, where R is selected from hydrogen, aliphatic, alkyl, heteroaliphatic, heteroalkyl, haloaliphatic, haloheteroaliphatic, aromatic, aryl, as defined herein, or any combination thereof. By thio is meant S.

    [0457] By thiol is meant an SH group.

    [0458] By thioalkoxy is meant an alkyl group, as defined herein, attached to the parent molecular group through a sulfur atom. Non-limiting examples of unsubstituted thioalkoxy groups include C.sub.1-6 thioalkoxy. In some embodiments, the thioalkoxy group is SR, in which R is an aliphatic or alkyl group, as defined herein.

    [0459] By thioalkoxyalkyl is meant an alkyl group, as defined herein, which is substituted with a thioalkoxy group, as defined herein. Non-limiting examples of unsubstituted thioalkoxyalkyl groups include between 2 to 12 carbons (C.sub.2-12 thioalkoxyalkyl), as well as those having an alkyl group with 1 to 6 carbons and a thioalkoxy group with 1 to 6 carbons (i.e., C.sub.1-6 thioalkoxy-C.sub.1-6 alkyl). In some embodiments, the thioalkoxyalkyl group is -L-SR, in which L is alkylene, as defined herein, and R is an alkyl group, as defined herein.

    II. Methods of Forming a Functionalized Material

    [0460] A functionalized material can be prepared in any useful manner. In some embodiments, a functionalization mixture is prepared, in which this mixture includes the substrate, a solvent, and one or more compounds to provide a functional portion. In some embodiments, at least one of the compounds includes an amine moiety, and at least one of the compounds includes a silane moiety. In particular embodiments, at least one compound includes both an amine moiety and a silane moiety. In other embodiments, at least one compound includes a crosslinking agent.

    [0461] The polymer coating, chelating agent(s), and/or antioxidant(s) are introduced at any useful operation described herein. For example and without limitation, in some embodiments a polymer for the polymer coating is introduced to the substrate prior to, during, or after the functionalization mixture is provided to the substrate. In another example, the chelating agent(s) is introduced to the substrate prior to, during, or after the functionalization mixture is provided to the substrate. In yet another example, the antioxidant(s) is introduced to the substrate prior to, during, or after the functionalization mixture is provided to the substrate. Optionally, in some embodiments, the chelating agent(s) and/or antioxidant(s) is introduced with the polymer of the polymer coating. In another option, the chelating agent(s) and/or antioxidant(s) is introduced with the functionalization mixture.

    [0462] In some embodiments the functionalization mixture is prepared in any useful manner. In one non-limiting example, a suspension mixture is prepared including the substrate and a solvent. To this suspension mixture, a compound (to provide a functional portion) is added to provide a functionalization mixture. Non-limiting examples of compounds include a silane coupling material, an aminosilane, a polyamine, or a combination of any of these compounds. In some embodiments, functionalization is conducted using solution-based reaction conditions.

    [0463] In some embodiments A crosslinking agent (to provide a linking moiety) is added to provide a crosslinking mixture. In some embodiments, the crosslinking agent is added to the functionalization mixture to provide a crosslinking mixture.

    [0464] Various methods are employed to provide the functionalized materials described herein. In some embodiments, the material is produced using solution-based reaction methods in which a silane-containing compound (e.g., an aminosilane compound with an amine moiety and a silane moiety) is solvated and a substrate (e.g., porous silica, MOF, or resin) is added. The silane moiety binds to the surface, and the amine moieties extend from the silane moiety. In some embodiments the resultant substrate is filtered from the solvent, washed, and dried. In some embodiments, such a material is further reacted with a polymeric/oligomeric amine compound. In some embodiments the mixture is stirred and then dried, thereby functionalizing the substrate with both the silane-containing compound and the polymeric/oligomeric amine.

    [0465] In other embodiments, a functionalized material is produced using solvent-based reaction methods in which a polyamine (e.g., a compound with a plurality of amine moieties) or an oligomeric ethylene amine compound (e.g., a compound with a plurality of ethylene groups and amine moieties, as well as mixtures of such compounds, including any described herein) with an optional aminosilane compound (e.g., a compound with an amine moiety and a silane moiety) is solvated (e.g., water-based reaction methods when the aminosilane compound is absent), and a substrate (e.g., porous silica, MOF, or resin) is added. When polyamine is used alone, in some embodiments, the polyamine has an increased number of amine moieties for increased carbon capture (e.g., >2 mol/kg) in the functionalized material. When both a polyamine and an aminosilane is employed, the polyamine and aminosilane compounds react to form a complex network, which in turn is bonded to a surface of the substrate. When the oligomeric ethylene amine compound or mixture thereof is used alone, in some embodiments, the oligomeric ethylene amine compound or a mixture thereof has an increased number of amine moieties for increased carbon capture (e.g., >1 mol/kg) in the functionalized material. The resulting material is stirred, optionally filtered from the solvent, optionally washed, and dried in some embodiments.

    [0466] Any method described herein (e.g., such as the process in FIGS. 3A-3E) provides any functionalized material described herein (e.g., a functionalized material 100A-100E in FIGS. 1A-1E).

    [0467] FIGS. 3A-3E are non-limiting flow chart diagrams showing examples of steps for producing a functionalized material. These diagrams are further described below.

    [0468] In some embodiments, the synthesis of the functionalized material is done under industrially applicable reaction conditions, such as liquid application to particles undergoing tumbling or mixing motion. After synthesis, the adsorbent can be optionally purified, dried, and optionally activated before using it as a CO.sub.2 adsorbent, such as coated particle 100. FIGS. 3A-E collectively illustrate examples processes 300 for making functionalized material, in accordance with some embodiments of the present disclosure. For example, FIGS. 3A-B collectively illustrate flow chart diagrams detailing a process 300 for making functionalized particles for use in a reversible adsorbent material, e.g., synthesizing a reversible CO.sub.2 adsorbent, such as coated particle 100.

    [0469] Referring to FIG. 3A, in some implementations, the process 300A is performed at large scale, e.g., producing 1 kilogram or more of functionalized crosslinked particles in a single process. In some implementations, the process 300A produces 100 kilograms or more of functionalized crosslinked particles (e.g., up to 10,000 kg). To maintain the original particle size distribution and reduce further attrition, in some embodiments agitation methods in which the particles are subjected to comparatively low friction or stirring forces are preferred, such as overhead stirring, gentle tumbling, slow and periodic stirring, or vibration.

    [0470] In some embodiments, the process produces at least 10, at least 20, at least 50, at least 100, at least 500, at least 1000, at least 2000, at least 5000, at least 10,000, or at least 100,000 kg of functionalized crosslinked particles. In some embodiments, the process produces no more than 500,000, no more than 100,000, no more than 10,000, no more than 5000, no more than 1000, no more than 500, no more than 100, or no more than 50 kg of functionalized crosslinked particles. In some embodiments, the process produces from 10 to 500, from 100 to 1000, from 500 to 2000, from 1000 to 10,000, from 5000 to 50,000, or from 50,000 to 500,000 kg of functionalized crosslinked particles. In some embodiments, the process produces another range of functionalized crosslinked particles starting no lower than 10 kg and ending no higher than 500,000 kg of functionalized crosslinked particles.

    [0471] In some embodiments, the process 300A includes preparing a functionalization mixture with a crosslinking agent to form a crosslinked mixture (step 302A).

    [0472] In some embodiments functionalizing the particles includes exposing the particles to a functionalization mixture. In some embodiments the functionalization mixture includes any compound(s) herein to provide a functional portion (e.g., one or more of amines, aminosilanes, polyamines, monoamines, or any combination of any of these), any compounds herein to provide a linking moiety (e.g., one or more crosslinking agents), any compound(s) herein to provide a polymer coating (e.g., one or more polymers, such as PVA), any chelating agent(s) herein, or any antioxidant(s) herein, as well as combinations of any of these.

    [0473] In one non-limiting embodiment, creating the functionalization mixture includes introducing a first reagent including a polyamine and a second reagent comprising a silane moiety and an amine functional group (e.g., an aminosilane) into a solvent to form a functionalization mixture. The solvent is an organic solvent in some embodiments. For example, in some embodiments the solvent is selected such that the polymer used to coat the particles is not miscible in the solvent, thereby minimizing removal of the protective polymer coating from the coated particles while introducing the polyamine and aminosilane. As used herein, the terms reagent and compound are used interchangeably. In some embodiments the reagent includes one or more solvents, salts, or other compounds. While an example of a functionalization mixture includes a polyamine and an aminosilane, any useful combination of compounds can be employed (e.g., any combination of one or more of an aminosilane, a silane, a polyamine that can include non-polymeric or polymeric amines, a monoamine, and the like).

    [0474] The first reagent, the second reagent, and the volume of solvent are dispensed and mixed. In some embodiments the first reagent is a polyamine (e.g., a polymeric amine), such as any polyamine described herein. In some embodiments the solvent is dispensed to fully suspend the polyamine, for example, by dispensing 20 mL/g of the solvent to polyamine (e.g., 10 mL/g, 15 mL/g, or 25 mL/g). In some embodiments the polyamine is added to the solvent in a range between 5% (wt/wt) and 60% (wt/wt) of the substrate to be functionalized in step 302A (e.g., 6% (wt/wt), 8% (wt/wt), 10% (wt/wt), 12% (wt/wt), 14% (wt/wt), 16% (wt/wt), or 18% (wt/wt), 20% (wt/wt), 30% (wt/wt), 40% (wt/wt), or 50% (wt/wt)).

    [0475] Alternatively, the solvent is dispensed to entirely cover the substrate within the vessel, for example, by dispensing from 1 mL/g to 15 mL/g of the solvent to the substrate (e.g., 1 mL/g, 5 mL/g, 8 mL/g, 15 mL/g, 2 to 2 mL/g, 2 to 2.5 mL/g, or other ranges herein). The solvent is any described herein (e.g., a neutral aprotic organic solvent, such as toluene, hexane, cyclohexane, or tetrahydrofuran (THF), as well as combinations of any of these).

    [0476] In some embodiments the second reagent is a silane coupling material, which can include a silane moiety (e.g., as in an amino silane or a silane, such as any described herein). In some embodiments the silane coupling material is dispensed in a range between 20% (wt/wt) to 80% (wt/wt) of a loading silane to the substrate to be functionalized in step 302A (e.g., 25% (wt/wt), 30% (wt/wt), 35% (wt/wt), 45% (wt/wt), 50% (wt/wt), or 60% (wt/wt)).

    [0477] In some embodiments the second reagent is an adsorbing moiety material, which can include one or more adsorbing moieties (e.g., one or more amine moieties, such as any described herein). In some embodiments the adsorbing moiety material is dispensed in a range between 20% (wt/wt) to 80% (wt/wt) of a loading silane to the substrate to be functionalized in step 302A (e.g., 25% (wt/wt), 30% (wt/wt), 35% (wt/wt), 45% (wt/wt), 50% (wt/wt), or 60% (wt/wt)).

    [0478] In some embodiments the liquid mixture is stirred until the polyamine and the silane coupling material are fully suspended in the solvent. In some examples, mechanical stirring with a propeller, a magnetic stirrer, or sonication disperses the polyamine in a time range from about 5 minutes (min) to 60 min (e.g., from 10 min to 30 min, from 5 min to 30 min, from 10 min to 45 min).

    [0479] In some implementations, one or more additives is included in the functionalization mixtures to extend the operational lifetime of the functionalized material. For example, in some embodiments the addition of bis[3-(trimethoxysilyl)propyl]amine) (BTMSPA) to the functionalization mixture increases the operational lifetime of the functionalized material. BTMSPA is an aminosilane having two ends, in which each end has a trimethoxysilyl reactive group. The BTMSPA bonds on the silica substrates with six binding points, as contrasted with the three binding points for an aminosilane with a single reactive group, such as would be present in a compound having a methoxydialkylsilyl reactive group. The increased number of binding points increases binding stability with the silica substrate. The BTMSPA forms a network with other aminosilanes and polyamines on the surface that increases binding stability of the overall network in some embodiments. In some embodiments, the addition of a chelator to the polymer used during coating increases the operational lifetime of the functionalized material. In yet other embodiments, the addition of an antioxidant with the polyamine and/or aminosilane used during functionalization increases the operational lifetime of the functionalized material.

    [0480] Optionally, the functionalization mixture is agitated for a duration to allow hydrolysis of and fully dissolve the silane coupling material and polyamine. In some non-limiting examples, the first time period is in a range from 1 min to 10 min (e.g., 5 min). Optionally, the functionalization mixture is heated (e.g., to a heating temperature above ambient temperature and below 90 C.) and/or cooled (e.g., passively, for example, by way of radiant cooling) to any useful temperature, such as room temperature).

    [0481] In the functionalization mixture, any useful crosslinking agent is introduced in some embodiments. In some embodiments, the crosslinking agent is introduced at a weight ratio of 5% or less wt/wt to another reagent present in the functionalization mixture (e.g., 4% or less, 3% or less, 2% or less, or 1% or less). In some embodiments, the crosslinking agent is present in an amount of about 0.1 mol % to 50 mol % of the crosslinking agent to the number of moles of amines present.

    [0482] In some examples, optional activation steps are performed to cause the crosslinking agent to be reactive and form the crosslinking network on the substrate and/or the surface modification layer. In some embodiments the optional steps include modulating a temperature, a pressure, an acidity, a humidity of one or more of the coating liquid, the porous particles, the first reagent, the second reagent, the third reagent, or the crosslinking agent. The optional activation steps are specific to the crosslinking agent of the material.

    [0483] In processes in which the optional activation steps are performed, the crosslinking agent is brought to (or below) the gelation point, e.g., the gel point. The gel point is specific a characteristic of crosslinker polymerizations that form networks over the surface of the substrate. The gel point and coating parameters to achieve the gel point, is specific to respective crosslinking agents. The gel point describes the point at which the network formation is substantially complete e.g., the majority of the components have been converted to a network.

    [0484] In some embodiments, the process 300A further include introducing porous particles (e.g., porous silica particles) to the functionalization mixture to provide a plurality of functionalized crosslinked particles (step 306A). In some embodiments the porous particles are provided by particles 102A-E of FIGS. 1A-1E.

    [0485] In some embodiments a crosslinking agent is added in any useful manner. As seen in FIG. 3B, a non-limiting process 300B for making functionalized material includes preparing a functionalization mixture (step 302B) and then introducing a crosslinking agent to the functionalization mixture to form a crosslinked mixture (step 302B). Then, the process 300B includes introducing porous particles to the crosslinked mixture to provide functionalized crosslinked particles (step 306B).

    [0486] As seen in FIG. 3C, a non-limiting process 300C for making functionalized material includes preparing a functionalization mixture (step 302C) and then introducing porous particles to the functionalization mixture to form functionalized particles (step 302C). Then, the process 300C includes introducing a crosslinking agent to the functionalized particles to provide functionalized crosslinked particles (step 306C).

    [0487] In some embodiments a polymer is employed in the process. As seen in FIG. 3D, in some embodiments the process 300D includes introducing porous particles (e.g., porous silica particles) to a crosslinking agent and a first reagent including a polymer to provide a plurality of crosslinked particles (step 302D). If a chelating agent is desired within the polymer coating, then any useful chelating agent (e.g., any described herein) is included with the first reagent.

    [0488] In some embodiments, the porous particles is provided by particle 102A-E of FIG. 1A-1E. In some embodiments a solvent into which the porous particles and the first reagent are introduced solvates the polymer and crosslinking agent into a coating liquid and provides the dissolved molecules to the porous particles. The dissolved molecules adsorb to the surfaces and pores of the particles to form crosslinked particles.

    [0489] In some embodiments the crosslinking agent is introduced at a ratio to the first reagent to crosslink a portion of the first reagent, e.g., less than all of the first reagent. In some embodiments, the crosslinking agent is introduced at a weight ratio of 5% or less wt/wt to the first reagent (e.g., 4% or less, 3% or less, 2% or less, or 1% or less). In some embodiments, the crosslinking agent is present in an amount of about 0.1 mol % to 50 mol % of the crosslinking agent to the number of moles of amines present.

    [0490] In some examples, optional activation steps are performed to cause the crosslinking agent to be reactive and form the crosslinking network on the substrate. In some embodiments the optional steps include modulating a temperature, a pressure, an acidity, and/or a humidity of one or more of the coating liquid, the porous particles, the first reagent, and the crosslinking agent. The optional activation steps are specific to the crosslinking agent of the material. Some of the crosslinking agents described herein may be heated (e.g., curing) to completely react. An example optional activation step is raising the temperature of the mixtures described herein to a temperature threshold for a duration. In one embodiment, the crosslinking agent is brought to a temperature threshold of 80 C. for a duration of 4 hours or less.

    [0491] In processes in which the optional activation steps are performed, the crosslinking agent is brought to (or below) the gelation point, e.g., the gel point. The gel point is a specific characteristic of crosslinker polymerizations that form 2- or 3-dimensional networks over the surface of the substrate. The gel point and coating parameters to achieve the gel point are specific to respective crosslinking agents.

    [0492] In one embodiment, the crosslinking agent is terephthalaldehyde and the crosslinking agent is applied to the substrate and dried. Then the amine-containing materials are applied to the substrate and the amines react with the terephthalaldehyde as it is heated and dried to form the crosslinked sorbent. If the crosslinked sorbent is exposed to water, less amines are removed compared to un-crosslinked sorbents as the amines are crosslinked into a network and are less soluble.

    [0493] In one embodiment, the crosslinking agent is terephthalaldehyde and the crosslinking agent and the solvent is a mixture of hexane/IPA. The amine-containing materials and the crosslinking agent are mixed in the solvent. Some crosslinking can occur in the mixture, e.g., the mixture does not fully crosslink, though additional steps of heating and/or drying the mixture on the substrate surface completes the crosslinking reaction. The solvent for step 302D depends on the polymer and crosslinking agent to be suspended. Using the example polymer provided herein, PVA is water-soluble and therefore an example of the solvent is water. In other embodiments, other solvents are selected based on the criteria of the polymer and crosslinking agent that creates the crosslinking coating.

    [0494] In an example, the process 300D can be a wet method, such as dip-coating, in which the volume of solvent is much larger than the volume of liquid the porous particles are capable of adsorbing. In some embodiments, the porous substrate particles are introduced to the solvent such that the particles are fully submerged in the solvent and at a wt:wt ratio in a range from 1.5 to 4:1 solvent to substrate (e.g., porous substrate particles). In some embodiments, the solvent to particle ratio is at least 0.5:1, at least 1:1, at least 1.5:1, at least 2:1, at least 2.5:1, at least 3:1, at least 3.5:1, or at least 4:1 wt/wt. In some embodiments, the solvent to particle ratio is no more than 5:1, no more than 4:1, no more than 3:1, no more than 2:1, or no more than 1:1 wt/wt. In some embodiments, the solvent to particle ratio falls within another range starting no lower than 0.5:1 wt/wt and ending no higher than 5:1 wt/wt.

    [0495] In some embodiments of the batch method, the polymer is introduced to the solvent at a ratio sufficient that the polymer is fully dissolved in the solvent, e.g., no precipitation occurs, no precipitant is present. In some embodiments, the quantity of polymer introduced to the solvent is sufficient to coat the quantity of porous substrate particles to be coated in the process 300D to achieve the desired characteristics described herein. In the example of PVA (or any other polymer), the polymer is introduced in a (wt/wt) percentage of up to 20% of the polymer to the substrate (e.g., porous substrate particles), such as, e.g., up to 18% (wt/wt), up to 12% (wt/wt), up to 8% (wt/wt), less than 12% (wt/wt), or less than 9% (wt/wt). In some embodiments, the polymer is introduced (e.g., to a first solvent) in a (wt/wt) percentage from about 1% to 20% (wt/wt) of the polymer to the substrate (e.g., from about 1% to 5%, 1% to 10%, 1% to 15%, 3% to 5%, 3% to 10%, 3% to 15%, 3% to 20%, 5% to 10%, 5% to 15%, 5% to 20%, 7% to 10%, 7% to 15%, 7% to 20%, 10% to 15%, 10% to 20%, 1 3% to 15%, 13% to 20%, or 15% to 20% (wt/wt)).

    [0496] Furthermore, in some embodiments one or more chelating agent(s) is introduced to a coating liquid including the polymer used to coat the substrate. In some embodiments, the chelating agent(s) is introduced in a (wt/wt) percentage of up to 5% of the chelating agent(s) to the substrate (e.g., porous particles), such as, e.g., from about 0.1% to 5% (wt/wt) to the substrate.

    [0497] In some embodiments, the process 300D is a spray method in which the volume of solvent is similar to the volume of liquid the porous particles are capable of adsorbing. In such an example, the solvent is introduced to the particles such that the particles are wetted by the solvent and at a wt:wt ratio in a range from 0.2 to 2.3:1 solvent to substrate (e.g., porous particles).

    [0498] In one embodiment, the crosslinking agent is applied in a separate step from the amine containing materials. In an embodiment of the spray method, the crosslinking agent is applied to (e.g., sprayed on) the silica substrate first and then the amine-containing materials are added. Alternatively, the amine-containing materials are added first and then the crosslinking agent. In one embodiment, the amine-containing materials and crosslinking agent are applied separately (e.g., from separate streams) and coincidentally (e.g., at substantially similar times) onto the substrate. In such an embodiment, the crosslinking reaction begins when the materials and agents mix on substrate surface.

    [0499] In some embodiments, the process 300D includes introducing a second reagent comprising at least one adsorbing moiety to the crosslinked particles, thereby providing a plurality of functionalized crosslinked particles (step 304D).

    [0500] Introducing the second reagent functionalizes the surfaces and pores of the coated particles with an adsorbing moiety (e.g., one or more amine moieties provided by a compound, such as an amine, an aminosilane, a polyamine, a monoamine, and the like). This also generates the plurality of functionalized coated particles for adsorbing CO.sub.2.

    [0501] In some embodiments the process 300D includes introducing an optional antioxidant, and a third reagent comprising at least one interaction moiety to the functionalized crosslinked particles (step 306D).

    [0502] In some embodiments, introducing the third reagent functionalizes the surfaces and pores of the coated particles with an interaction moiety (e.g., a silane moiety provided by a compound, such as a silane, an aminosilane, and the like). In some embodiments, the second reagent is a polyamine, and the third reagent is an aminosilane. Other combinations are possible (e.g., any described herein). For example, and without limitation, in some embodiments the second reagent is an amine (e.g., a polyamine, a monoamine, or an aminosilane), and the third reagent is an aminosilane or a silane (e.g., any described herein). In some embodiments, the second reagent includes both an adsorbing moiety and an interaction moiety (e.g., as in aminosilane), and the third reagent is omitted.

    [0503] Introducing the antioxidant(s) provides compounds to scavenge oxygen or other oxidative species, which in turn results in reduced oxidation of amine-containing functional groups of the adsorbing species.

    [0504] In some embodiments, the polymer coating, interaction moiety, and adsorbing moiety to create a functionalized coated material is done before the crosslinking agent is introduced. As seen in FIG. 3E, such a process 300E includes introducing porous particles (e.g., porous silica particles) to a first reagent including a polymer to provide a plurality of coated particles (step 302E). Any useful chelating agent in any useful amount (e.g., any described herein) can be included with the first reagent.

    [0505] The process 300E further includes functionalizing the coated particles by exposing the particles to a functionalization mixture (step 304E). In turn, the functionalization mixture includes a second reagent and a third reagent. Details regarding the second and third reagents are as provided herein for process 300A.

    [0506] Optionally, an antioxidant (e.g., any useful antioxidant in any useful amount, such as described herein) is introduced in step 302E or 304E.

    [0507] The process 300E further includes crosslinking the coated particles by exposing the particles to a crosslinking agent (step 306E). Any useful crosslinking agent in any useful amount (e.g., any described herein) is included. In some examples, optional activation steps are performed to cause the crosslinking agent to be reactive and form the crosslinking network on the substrate. The optional steps include modulating a temperature, a pressure, an acidity, a humidity of one or more of the coating liquid, the porous particles, the first reagent, or the crosslinking agent. The optional activation steps are specific to the crosslinking agent of the material.

    [0508] The steps of the process 300A-300E, e.g., steps 302A-E, 304B-E, or 306A-E, can be performed in any order, e.g., in other examples, the particles are crosslinked and then functionalized; the particles are functionalized and then crosslinked; the particles are functionalized, chelated, and then coated; the particles are coated, functionalized, and then crosslinked; or the particles are functionalized, crosslinked, and then coated; or the particles are functionalized and then coated, with optional drying separating the steps.

    [0509] Optionally, the process 300A-E includes one or more steps (e.g., a separate step or a step combined with another step present in the process) for introducing a fifth reagent comprising an antioxidant. Examples of antioxidants for use in the method include sacrificial antioxidants and cyclic antioxidants. In some examples, more than one antioxidant is introduced. In some embodiments, the antioxidant(s) are added during steps 302A-E, 304B-E, or 306A-E of the process 300A-E, or afterward.

    [0510] Optionally, the process 300A-E includes one or more steps for washing the surface of the porous particles to minimize the presence of one or more metals. In some embodiments, washing includes the use of an acid (e.g., a dilute acid).

    [0511] Optionally, any of processes 300A-E include one or more steps for oxidizing metals present in porous particles by raising the temperature of the particles above a threshold for a duration before the first, second, third, fourth, or fifth reagents are introduced. Metals found on the surfaces and pores of porous particles are available for oxygenation during the lifetime of the functionalized particles. By raising the temperature of the porous particles, the metals are completely- or near-completely oxidized, in some embodiments, thereby reducing the effects of oxidation on the functionalized particles during carbon capture processes when the functionalized particles are exposed to atmospheric oxygen. One non-limiting example of the temperature threshold is 300 C. (e.g., 400 C., 500 C.). One non-limiting example of the duration is at least one hour (e.g., at least two hours, at least three hours).

    [0512] The temperature to which the porous silica particles are raised depends on the composition of metals that are determined to be present in the porous silica particles, in some embodiments. Iron and copper are examples of metal contaminants that can be oxidized by raising the temperature of the porous silica particles in the presence of an oxygen-containing gas, e.g., air.

    [0513] Optionally, any of the processes 300A-E includes one or more steps for filtering the coated particles, functionalized coated particles, or both. In some embodiments filtering is performed using methods known in the art for separating solid phase from liquid phase. This includes, but is not limited to, vacuum filtration, centrifugation, vacuum evaporation, or a combination of these or other methods. The volume of solvent separated from the coated particles or functionalized particles is discarded, stored, or recycled, in some embodiments.

    [0514] Optionally, any of processes 300A-E includes washing the substrate, coated particles, and/or functionalized coated particles in at least one wash volume of fresh (e.g., a new volume) solvent medium. For example, in some embodiments, the functionalized material is immersed in a wash volume of fresh solvent medium (e.g., 40 mL of solvent for 4 g of functionalized material), in which a single wash or a plurality of washes is performed. In some embodiments, the wash solvent dissolves the silane moiety to remove moieties coated on the surface of functionalized substrate but not reacted.

    [0515] Optionally, any of processes 300A-E includes one or more steps for drying the coated particles, functionalized coated particles, or both. In some embodiments, drying the particles includes increasing the temperature, reducing the atmospheric pressure, passing an inert dry gas over the sample, passing a heated dry gas over the sample, or a combination of these. In some embodiments, drying occur after the particles are introduced to the coating mixture, after the particles are introduced to the functionalization mixture, or both, in order to remove substantially all of the first solvent, or the second solvent entrained in or on the particles. In the case of drying the enhanced particles, the coating is strengthened during drying in some embodiments.

    [0516] For example, in some embodiments, the functionalized material is dried in an oven (e.g., a vacuum oven) at 50 C. for 12 hours, e.g., overnight, or at 70 C. for between 5 minutes and 20 minutes. Drying times longer than 60 minutes at elevated temperatures reduce the adsorption capacity of the final product in some embodiments. However, the drying time is scale- or condition(s)-dependent in some embodiments. For example, drying under N.sub.2 or vacuum, the drying time is longer in some embodiments. In examples in which batch drying is performed, even with N.sub.2 or vacuum, drying times is longer than 60 minutes in some embodiments, depending on the scale of the functionalized particles that are being dried. Alternatively, in some embodiments the functionalized material is dried until a hydration threshold is reached. As non-limiting examples, the drying threshold is a weight lost by the sample of 15% (e.g., weight lost to solvent removal) or having minimal weight loss (e.g., a weight loss of less than about 5% over a period of about 2 hours at 100 C.) with an inert gas flow (e.g., 50 mL/minute of N.sub.2 flow) through the sample (e.g., as measured on TGA)). In some embodiments, the functionalized material is dried until a hydration threshold is reached, e.g., such as <5% (wt/wt) solvent to functionalized material remains. In some embodiments the functionalized material is then be prepared for use as a reversible sorbent material.

    [0517] In some embodiments the sorbent particles are reused through the desorption process. For example, in some embodiments the adsorbent is reused 100 times or more (e.g., 1000 times or more, 10000 times or more). For the desorption process, in some embodiments samples are heated to 70 C. or higher under vacuum for 30 minutes (the duration may change based on temperature and/or vacuum level). Without wishing to be limited by theory, in some embodiments, this facilitates release of CO.sub.2 captured during the adsorption process, in which release CO.sub.2 is collected for further sequestration, described with reference to the systems for direct air capture herein. A non-limiting aspect of the desorption process is to maintain the sorbent heated under a water vapor filled vacuum environment (e.g., >10% relative humidity) in some embodiments. Without wishing to be limited by mechanism, this can reduce sorbent degradation.

    III. Production Systems

    [0518] Any useful component can be used to form a functionalized material. In some embodiments, one or more components can be employed in a dip coating system. FIGS. 4-9 are example systems by which a functionalized material can be produced in coating and functionalization methods, such as process 300A-E, described herein.

    [0519] FIGS. 4A-4B shows a double cone tumble mixing system 400 which includes a tumbler 402 having an inlet 404, outlet 406, and an inner volume 408. The double cone mixing system 400 results in a high degree of particle mobility during mixing when the substrate is added to the inner volume 408 through the inlet 404. In general, the contents of the tumbler 402 are mixed by rotating the tumbler 402 around a central horizontal axis.

    [0520] The double cone tumble mixing system 400 is an efficient machine for mixing of dry powders and granules homogeneously. All of the surfaces that contact the contents can be manufactured from non-reactive metal, such as stainless steel, glass, or glass-coated interior, to prevent interaction with the polymer for coating, silane compounds, the polyamines, or the substrate (e.g., silica particles). In general and without wishing to be bound by theory, the effective volume for optimum homogeneity is between 35-70% of the inner volume 408 of the tumbler 402. The double cone tumble mixing system 400 is advantageous for use with fragile substrates (e.g., fragile silica particles) as the cone-shapes and smooth inner walls of the tumbler 402 reduce attrition of the substrate during agitation.

    [0521] In general, the coating liquid components (e.g., including a polymer to provide a polymer coating) and/or functionalization mixture components are poured into the inlet 404 and allowed to form the coating liquid/functionalization mixture. In other words, the polymer, aminosilanes, the polyamines, and/or a volume of solvent (e.g., water) water are sprayed into the inner volume 408 of the mixing system 400, shown in the left-most image of FIG. 4A. Spraying can be conducted within components in multiple steps (e.g., in which the coating liquid is first formed and then functionalization mixture components are provided; or in which the functionalization mixture is first formed and then the polymer for coating is provided). If necessary, the inlet 404 is sealed and the components agitated within the mixing system 400 to form, or hasten the formation of, the coating liquid/functionalization mixture.

    [0522] The substrate (e.g., porous silica particles) are added to the coating liquid/functionalization mixture through the inlet 404 and the tumbler 402 is sealed and agitated, shown in the central image of FIG. 4A.

    [0523] The coated material can be separated from the coating by opening the outlet 406 and decanting the coating (the right-most image of FIG. 4A) from the coated particles through filtration or other means.

    [0524] Similarly, the functionalized material can be separated from the functionalization mixture by opening the outlet 406 and decanting the functionalization mixture (the right-most image of FIG. 4A) from the functionalized material through filtration or other means. In some examples, the tumbler 402 does not include an outlet 406, and the inlet 404 is instead used to decant the functionalization mixture and separate the functionalized material. In one example, the porous substrate is added into the mixing system 400 first. Then a functionalization mixture is sprayed over the substrate as the mixing system 400 spins so that a uniform coating is obtained. Then heat and vacuum are applied to remove the solvent.

    [0525] In some examples, the mixing system 400 is used to coat, functionalize, and dry the particles. In FIG. 4B, the mixing system 400 applies heat 418 to the inner volume 408 of the tumbler 402 which causes excess solvent used coating liquid/functionalization mixture absorbed by the coated and/or functionalized material to evaporate. The tumbler 402 is rotated to agitate the coated and/or functionalized material, which increases the evaporation rate of the absorbed coating liquid/functionalization mixture during heating.

    [0526] FIG. 5 is three images of an example Nutsche filter mixing system 500 that effectively performs the separation of solid matter from a liquid under pressure or vacuum in a closed system. The left-most image of FIG. 5 shows a cut-away view of the mixing system 500. The mixing system 500 includes a vessel 502 having an inlet 504, filter discharge 510, and outlet 514. Some examples of the vessel 502 are jacketed for temperature control. An agitator 506 is rotatable within the vessel 502 by a drive motor 508 around the drive motor 508 shaft. The inlet 504 receives the coating liquid (e.g., including a polymer to provide a polymer coating), functionalization mixture components including the silane compounds, polyamines, volume of solvent (e.g., water), and/or substrate (e.g., particles).

    [0527] The drive motor 508 rotates the agitator 506 such that the mixture is stirred and shear forces are applied to the substrate and functionalization mixture. The substrate is mobilized within the coating liquid/functionalization mixture. The vessel 502 includes a filter 512 sized to separate the solid particles and the coating liquid/functionalization mixture during agitation, coating, and/or functionalization. When the discharge 510 and outlet 514 are open, the liquids are removed from the vessel 502 and discarded while the filter 512 separates the coated and/or functionalized material. The filter 512 can be wire mesh, a cloth layer, or a perforated metal layer.

    [0528] Some examples of the mixing system 500 include a heating mechanism integrated into the filter 512 such that, following decanting of the coating liquid/functionalization mixture in the right-most image of FIG. 5, the separated coated and/or functionalized material can be dried within the vessel 502.

    [0529] FIG. 6 is three images of a filtration bag dip-coating method used to produce a functionalized material. An open-topped container 602, e.g., a vat, is filled with the liquid components of the coating liquid/functionalization mixture and allowed to produce a homogeneous mixture. In some examples, the liquid components are agitated to produce the homogeneous mixture. In the left-most image, a mesh filtration bag 604 is filled with the substrate (e.g., silica particles) to be coated and/or functionalized. The mesh of the filtration bag 604 is sufficiently small to permit liquid ingress while withholding the substrate (e.g., particulates of the silica particles). In some cases, the mesh is large enough to permit fine dust to be separated from the substrate when the filtration bag 604 is submerged.

    [0530] In the central image of FIG. 6, the filtration bag 604 is submerged within the liquid components and rested for a duration. The filtration bag 604 can be moved within the container 602 to facilitate uniform contact between the coating liquid/functionalization mixture and the substrate contained within the filtration bag 604. The uniform contact produces homogenous coated and/or functionalized material when the filtration bag 604 is withdrawn and the coated and/or functionalized material is dried.

    [0531] In the right-most image of FIG. 6, the filtration bag 604 is withdrawn from the container 602 and the excess coating liquid/functionalization mixture decanted, e.g., drained, such that the coated and/or functionalized material is maintained in the filtration bag 604. The coated and/or functionalized material (e.g., functionalized silica particles) can then be removed from the filtration bag 604 and dried to complete the coating and/or functionalization process.

    [0532] FIGS. 7 and 8 show two different examples of drum mixers which can be used for mixing the coating liquid/functionalization mixture, exposing the particles to the coating liquid/functionalization mixture thereby coating and/or functionalizing the particles, and/or drying of the coated and/or functionalized particles. In the left image of FIG. 7, a paddle mixer 700 includes a cylindrical drum 702 in which mixing occurs. A paddle agitator 704 rotates independently of the drum 702 to mix the coating liquid/functionalization mixture with the substrate. the substrate is dispensed into the drum 702, and the paddle agitator 704 rotates to agitate the substrate (e.g., silica particles) in the coating liquid/functionalization mixture.

    [0533] In the left image of FIG. 8, a ribbon mixer 800 includes cylindrical drum 802 in which mixing occurs by a ribbon agitator 804, which rotates independently of the drum 802.

    [0534] The substrate (e.g., silica particles) is dispensed into the drum 802, and the ribbon agitator 804 rotates to agitate the substrate (e.g., silica particles) in the coating liquid/functionalization mixture.

    [0535] Examples of the paddle mixer 700 and ribbon mixer 800 can include heating mechanisms, such as jacketed drums 702 and 802, or forced gas venting to flow heated gas over the coated and/or functionalized material after separating the solid substrate from the coating liquid/functionalization mixture. In some examples, the heated gas can be air, or an inert gas (e.g., nitrogen, N.sub.2). If a heat carrier is flown through a jacket of the paddle mixer 700 or ribbon mixer 800, the heat carrier can be heated oil, steam, or hot water. If the heat carrier is flown inside the vessel (e.g., forced gas venting), an inert gas such as N.sub.2 can be used. However, in examples of forced gas venting air should be avoided to prevent oxidation. In this way, the paddle mixer 700 and ribbon mixer 800 can be used to coat/functionalize and dry the coated and/or functionalized material. The mixers 700 and 800 apply heat to the inner volume of the mixers, which causes solvent from the coating liquid/functionalization mixture absorbed by the functionalized material to evaporate. As the agitators 704 and 804 are rotated to agitate the coated and/or functionalized material, the evaporation rate of the absorbed coating liquid/functionalization mixture increases during heating.

    [0536] FIGS. 9A-9B illustrate an example dip-coating conveyor system 900 in which silica particles to be functionalized are placed in a container 902 and conveyed through the dip-coating process by a conveyor 904. The container 902 shown is an open-top vessel, though in other examples a mesh bag containing the substrate is functional with the conveyor system 900. The container 902 can be solid or perforated to facilitate rapid and complete absorption of the coating liquid/functionalization mixture by the substrate.

    [0537] FIG. 9A illustrates the container 902 arranged on the conveyor 904. The conveyor is operated by a controller, which causes the container 902 to enter a dip tank 906. The dip tank 906 contains the coating liquid/functionalization mixture including the polymer for the polymer coating, aminosilanes, and/or polyamines to coat and/or functionalize the substrate (e.g., silica particles). Some examples of the dip tank 906 include agitation elements, such as mixing or stirring blades, or pumps.

    [0538] The conveyor 904 transports the container 902 into the dip tank 906. The conveyor 904 operates continuously, or intermittently, so the container 902 spends sufficient time within the coating liquid/functionalization mixture to coat and/or functionalize the substrate. The conveyor 904 operates to remove the container 902 from the coating liquid/functionalization mixture.

    [0539] The conveyor system 900 includes a dryer 908 after the dip tank 906 for removing excess coating liquid/functionalization mixture from the coated and/or functionalized material (e.g., functionalized silica particles). The dryer 908 can raise the temperature of the substrate by blowing heated gas, through passive heating elements, or both.

    [0540] FIG. 9B illustrates the conveyor system 900 operating in a continuous mode in which multiple containers 902 are transported by the conveyor 904 concurrently. FIG. 9B illustrates containers 902a, 902b, and 902c each at different stages of the dip-coating process. In this manner, the conveyor system 900 can be operated efficiently to dip-coat and dry batches of the silica particles sequentially.

    IV. Methods of Using or Testing a Functionalized Material

    [0541] The functionalized material may be used as a sorbent. Described herein are methods and systems to test such materials.

    i. Methods of Using a Functionalized Material

    [0542] The present disclosure encompasses methods of using a functionalized material to remove atmospheric CO.sub.2 from air by direct air capture. In addition to air, the functionalized material can be used to remove CO.sub.2 from a fluid.

    [0543] Methods of use can include providing a functionalized material for capturing (e.g., reversibly capturing) CO.sub.2. In general, the functionalized material is a layer of conventional or uniform beads, granules, pellets, fibers, membranes, or powders over which gaseous mixtures including CO.sub.2 are flowed. Gas exiting the layer of functionalized material has a lower concentration of CO.sub.2 than the entering gas.

    [0544] Capture of CO.sub.2 can be achieved by using a reactor or a sample holder, e.g., such as any described herein. Accordingly, methods of use can include: providing air to a reactor (e.g., any described herein) or a sample holder (e.g., any described herein) comprising a sorbent, where the sorbent can include a functionalized material (e.g., any described herein); and exposing the sorbent to conditions to adsorb CO.sub.2 from the air to form CO.sub.2-reduced air. In some embodiments, the sorbent is provided as a fluidized bed.

    [0545] Methods of use can further include: releasing adsorbed CO.sub.2 under certain conditions to desorb CO.sub.2 from the sorbent to form CO.sub.2-enriched air. Non-limiting conditions can include, e.g., a temperature swing adsorption process, a pressure swing adsorption, a vacuum swing adsorption process, or a combination of any of these.

    [0546] In some embodiments, the method includes: providing ambient air comprising CO.sub.2 to a reactor (e.g., any described herein) comprising one or more air chambers; blowing the ambient air so that it travels from the one or more air chambers into a reaction chamber; delivering a powdered sorbent material to the reaction chamber through an inlet; creating a fluidized bed of the powdered sorbent material and the air under conditions in which the powdered sorbent material adsorbs the CO.sub.2 from the air to form CO.sub.2-reduced air and used powdered sorbent material; continuously removing used powdered sorbent material from the reaction chamber; and continuously removing CO.sub.2-reduced air from the reaction chamber through one or more exhaust ports.

    ii. Sample Holder

    [0547] The functionalized material can be provided in a sample holder for testing and/or during use as a sorbent. FIG. 10A schematically illustrates an exploded view (left) and an assembled view (right) of a non-limiting sample holder 1000 for the sorbent. Functionalized material can be placed in a sample space 1006 arranged between two layers of filter 1004 (e.g., such as glass wool) in a sample holder 1000. The sealing ends 1002 of the sample holder 1000 can include an inlet 1008 and an outlet 1010 permissive to gas flow. The sealing ends 1002 can include reversible screw connections to assemble the sample holder 1000. When assembled (right), the sample holder 1000 was otherwise sealed against gaseous inflow.

    [0548] In FIG. 10B, a schematic diagram of the experimental setup 1020 is shown. Referring now to FIGS. 10A and 10B, a gas source, e.g., air compressor 1022, provided compressed environmental air to the inlet 1008 of the testing sample holder 1000. The air passes through the filters 1004, thereby exposing the functionalized material to the environmental air. Air can be exhausted from the outlet 1010. The concentration of CO.sub.2 in the compressed environmental air can be measured by a gas analyzer, e.g., CO.sub.2 gas analyzers 1024 and 1026, prior to entering the inlet 1008 and subsequent to exiting the outlet 1010.

    [0549] The samples of functionalized material were treated with an activation process before data collection. Samples were heated in a vacuum drier (e.g., vacuum heater 1028) to 70 C. for 30 minutes under vacuum (e.g., at 0.3 psi) to activate the sorbent, e.g., as the activation process. Alternatively, and as shown in FIG. 10B, the heating element 1028 and the vacuum system 1030 are separate elements of the setup 1020 and work in concert to heat and apply vacuum to the sample holder 1000. In some implementations, a cooling element 1032 is included in the setup 1020 to further control the temperature of the environment in the sample holder 1000. Both the heating element 1028 and the cooling element 1032 are integrated into the sample holder 1000 in the experimental setup 1020 to apply temperature control directly to the sorbent sample. The activation process can facilitate removal, e.g., evaporation, of residual solvent medium in the pores of the functionalized silica and desorbs CO.sub.2 molecules bonded during the synthesis process (e.g., processes 300A-B) for venting to the atmosphere.

    [0550] For a non-limiting adsorption procedure, samples of functionalized silica in a range between 0.5 g and 10 g were placed in between two layers of glass fiber filters 1004 in the testing sample holder 1000. Compressed environmental air (e.g., input air) from a gas source 1022 can be continuously fed through the testing sample holder 1000 at a rate in a range from 1 to 10 standard liters per minute (slpm), thereby exposing the activated functionalized material. The activated functionalized material was exposed for time periods in a range from 30 to 60 minutes. The humidity of the input air can be controlled to be in a range between 15% to 50% relative humidity (RH) at 21 C. As the activated functionalized material adsorbs CO.sub.2, the concentration of CO.sub.2 is measured both before the sample holder with CO.sub.2 gas analyzer 1024 and after the sample holder with CO.sub.2 gas analyzer 1026. The same sample holder can then be brought to vacuum by a vacuum system 1030 and heated by a heating element 1028 to extract the carbon dioxide from the sample. The amount of carbon dioxide extracted was also measured by gas analyzer 1026.

    [0551] The humidity can be controlled through blending of dry air and wet air with a flow meter (not shown). As an example, to produce input air having 50% relative humidity (RH) at a flow rate of 5 slpm, dry air (e.g., <10% RH) at 2.5 slpm and wet air (e.g., >95% RH or 100% RH) can be blended at 2.5 slpm each. The dry air and wet air flow control can be accomplished using a closed loop controller.

    [0552] The compressed environmental air including CO.sub.2 concentration can be monitored by gas analyzers 1024 and 1026 at the input and output of the testing sample holder 1000 during the experimental time period in units of mol CO.sub.2/kg of sorbent.

    V. Example Direct Air Capture Systems

    [0553] Disclosed herein are systems for employing a functionalized material. In some embodiments, the functionalized material is used as a sorbent in a fluidized bed reactor for use in direct air capture (DAC).

    [0554] Examples of DAC systems of CO.sub.2 using the sorbent of the present disclosure are described with reference to FIGS. 11A-11B and FIG. 12, examples of which are described in U.S. Pat. Pub. No. 2021/0300765 or Int. Pub. No. WO 2021/202499, the disclosure of which are hereby incorporated by reference in their entirety.

    [0555] FIG. 11A is a schematic illustration of an example implementation of a carbon dioxide extraction system 1100 that uses waste heat to provide energy for a carbon dioxide direct air capture (DAC) system 1115. As illustrated, the carbon dioxide extraction system 1100 includes an industrial process 1105 that generates waste heat 1102. In some implementations, the industrial process utilizes a power input 1103. The waste heat 1102 is supplied, in this example, to a thermal heat-reuse system 1110 that also utilizes a power input 1106.

    [0556] The thermal heat-reuse system 1110 provides a heated fluid 1104 to a carbon dioxide DAC system 1115. The carbon dioxide DAC system 1115 also receives a power input 1108 and an ambient airflow input 1111. The carbon dioxide DAC system 1115 outputs a carbon dioxide supply stream 1112, a carbon dioxide-reduced airflow output stream 1114, and demineralized water 1116. As will be discussed in greater detail herein, DAC system 1115 includes an adsorber system (e.g., that may optionally comprise a fluidized bed reactor or a silo adsorber) and a desorber system (e.g., that may optionally comprise a gravity fed desorption system).

    [0557] Generally, the carbon dioxide extraction system 1100 operates to utilize the heated fluid 1104 as thermal energy that is generated from the waste heat 1102 by the thermal heat-reuse system 1110. The thermal energy in the heated fluid 1104 is used by the carbon dioxide DAC system to separate carbon dioxide captured from the ambient airflow input 1111 and supply the separated carbon dioxide as the carbon dioxide supply stream 1112. The heated fluid 1104 is then returned via heated fluid return 1113 to the thermal heat-reuse system 1110, and the waste heat 1102 is returned to the industrial process 1105 via waste heat return 1117. In some aspects, the carbon dioxide supply stream 1112 can be provided as an injectant into a subterranean formation during hydrocarbon production operations. In some aspects, the injected carbon dioxide may be sequestered in the subterranean formation (with or without assisting in the hydrocarbon production operations).

    [0558] The industrial process 1105 may be any process that generates, as an output, thermal energy in the form of waste heat, e.g., energy, that, unless captured, that otherwise would be lost to, e.g., the ambient environment. As an example, the industrial process 1105 may be a computer data center that, generally, houses computer systems and associated components, such as telecommunications and storage systems. In some aspects, a data center includes tens, hundreds, thousands, or even more server devices that generate heat, such as hardware processors, voltage regulators, memory modules, switches, and other devices that operate to provide a particular amount of information technology (IT) power.

    [0559] Such devices, typically, utilize electrical power to operate and output heat during operation. In order for such devices to operate correctly, the output heat must be captured in a cooling fluid flow (e.g., air, water, refrigerant) and expelled from the data center. For instance, air handling systems (e.g., fans, cooling coils).sub.may operate to capture the output heat in an airflow circulated over the heat-generating components. The output heat now within the airflow is transferred to a cooling liquid, e.g., within a cooling coil. The heat transferred to the cooling liquid is then typically rejected to the ambient environment as waste heat, such as through evaporative cooling systems, chiller/cooling tower systems, or otherwise. In this example, this waste heat takes the form of waste heat 1102.

    [0560] The example thermal heat-reuse system 1110 utilizes the waste heat 1102 and power input 1108 to provide the heated fluid 1104. The thermal heat reuse system 1110 comprises a bank of heat pumps and a bank of heat exchangers to provide the heated fluid 1104. By balancing the use of passive and active heating, power can be saved to provide the carbon dioxide DAC system with the required temperatures of heated fluid 1104. Generally, the thermal heat-reuse system 1110 includes one or more vapor -compression cycles (heat pumps) to add thermal energy in the form of heat of compression to the waste heat 1102 and transfer the sum of such energy to a fluid to generate the heated fluid 1104 (e.g., a heated liquid). Generally, each heat pump and heat exchanger within the thermal heat-reuse system 1110 operates to transfer thermal energy from a heat sink to a heat source, i.e., in an opposite direction of spontaneous heat transfer. The one or more heat pumps of the thermal heat-reuse system 1110 use the power input 1106 to accomplish the work of transferring energy from the heat source to the heat sink. Each heat pump in the thermal heat-reuse system 1110 includes the primary components of two heat exchangers (one acting as an evaporator, one acting as a condenser), an expansion device (e.g., valve or fixed orifice), and a compressor (e.g., centrifugal, screw, reciprocating, scroll, or otherwise). Each of these components is fluidly coupled within a closed-loop refrigerant circuit in the heat pump.

    [0561] As is generally known, in a vapor -compression heat pump cycle, a refrigerant exits a first heat exchanger in which heat from the refrigerant is released to a first medium. The refrigerant then enters a compressor in which it is compressed, and a heat of compression is added thereto. The refrigerant then enters a second heat exchanger in which heat from a second medium is added. The refrigerant then enters an expansion device and undergoes an isenthalpic pressure drop. The refrigerant completes the cycle by entering the evaporator to release the heat of compression and the heat from the second medium to the first medium.

    [0562] Although the present disclosure describes a vapor -compression heat pump cycle as a heat transfer system between a source of waste heat and a carbon dioxide DAC system, other thermodynamic cycles may also be used in place of (or along with) the described vapor -compression heat pump cycle. For example, one or more vapor -adsorption cycles may be used in place of (or along with) the described vapor -compression heat pump cycle. A vapor -adsorption cycle, for example, consists of a cycle of desorption-condensation-expansion-evaporation, followed by adsorption.

    [0563] The carbon dioxide DAC system 1115, generally, operates to pass the ambient airflow input 1111 (which includes low concentrations of gaseous carbon dioxide) over or through one or more media (e.g., filters). In some aspects, one or more fans (not shown) utilize the power input 1108 to circulate the ambient airflow input 1111. The media or filter, in some aspects, includes a solid sorbent to which the atmospheric carbon dioxide in the airflow input 1111 bonds. The sorbent that is saturated with carbon dioxide may be referred to as rich sorbent.

    [0564] In the case of a solid sorbent, such as the sorbent described in the present disclosure, as the airflow input 1111 passes over the solid media or filter, atmospheric carbon dioxide within the airflow input 1111 bonds to the media or filter. When the media or filter is saturated with carbon dioxide, it can be heated (e.g., to 600-620 C. or to 60-100 C.) to release the carbon dioxide for collection (as described herein).

    [0565] Using thermal energy from the heated fluid 1104, heat is applied to the solid or liquid sorbent, which breaks the bonds between the carbon dioxide and the sorbent. The separated carbon dioxide is provided as the carbon dioxide supply stream 1112 from the carbon dioxide DAC system 1115. The now-lean adsorbent that is carbon dioxide free (e.g., the solid or liquid) is recycled back to capture more carbon dioxide from the ambient airflow input 1111. The airflow output 1114, typically, contains little to no carbon dioxide.

    [0566] FIG. 11B shows an example carbon dioxide DAC system 1115. The carbon dioxide DAC system 1115 includes an adsorber system 1126 and a desorber system 1128.

    [0567] The adsorber system 1126 generally operates to pass the ambient airflow input 1111 (which includes gaseous carbon dioxide) over or through one or more sorbents (e.g., in media or filters) under conditions at which the sorbent adsorbs CO.sub.2 from the air. In some embodiments, the sorbent is provided within a fluidized bed reactor, where air flows through an air inlet into a reaction chamber and will diffuse through a distribution plate to make contact with the sorbent. In some embodiments, the adsorber system can include any useful adsorber. In other embodiments, air can flow through one or more filter panels of a silo adsorber.

    [0568] The desorber system 1128 generally operates to remove adsorbed carbon dioxide from sorbent material. The desorber system can include, for example, any useful desorption system.

    [0569] In some aspects, one or more fans (not shown) utilize the power input 1108 to circulate the ambient airflow input 1111. For example, a blower can use the power input 1108 to circulate airflow input to a chamber of a silo adsorber.

    [0570] The media, filter, or sorbent, in some aspects, includes a solid sorbent to which the atmospheric carbon dioxide in the airflow input 1111 bonds. For example, the solid sorbent can be in a pelletized or powdered form. Alternatively, a liquid sorbent may be also passed over the media or filter to which the atmospheric carbon dioxide in the airflow input 1111 bonds. The sorbent that is saturated with carbon dioxide may be referred to as rich sorbent. Rich sorbent 1122 exits the adsorber system 1126 and enters the desorber system 1128. Carbon dioxide-reduced air exits the adsorber system 1126 through the airflow output 1114.

    [0571] As the airflow input 1111 passes over the sorbent (e.g., as a solid media and/or with a filter), atmospheric carbon dioxide within the airflow input 1111 bonds to the sorbent. The airflow output 1114 exits the system as carbon dioxide-reduced air and is released into the atmosphere. The airflow output 1114, typically, contains little to no carbon dioxide. When the sorbent is saturated with carbon dioxide, it can be heated (e.g., to 70-120 C.) to release the carbon dioxide for collection.

    [0572] In some aspects, a powdered sorbent material can be used. For example, silica -based sorbent powders are possible, e.g., porous silica functionalized with an amine compound. In some cases, metal oxide framework (MOF) powders can also be used. The degree of coarseness (granularity) of the powder can vary depending on the application. In some cases, particles with an average grain size in a range from 50 to 1,700 m or from 50 to 3,000 m can be used. In some examples, the sorbent powder is pelletized.

    [0573] In some aspects, for example, if liquid sorbent is used, such liquid has a high affinity for carbon dioxide and is circulated over a non-reactive metal (or other material) filter. Once saturated with carbon dioxide, the liquid can be heated (e.g., to 800 C.) to release the carbon dioxide (as described herein). The liquid can then be reused to capture more carbon dioxide in a continual cycle.

    [0574] The desorber system 1128 uses thermal energy from the heated fluid 1104 to apply heat to the solid or liquid rich sorbent 1122. The heat dissolves the bonds between the carbon dioxide and the rich sorbent 1122. The heated fluid return 1113 exits the desorber system 1128 in order to collect more heat from a process outside of the carbon dioxide DAC system. The separated carbon dioxide is provided as the carbon dioxide supply stream 1112 from the carbon dioxide DAC system 1115. The heat also dissolves bonds between water molecules and the rich sorbent 1122, which exits the system as demineralized water output 1116. The sorbent exiting the desorber system 1128 may be referred to as lean sorbent, e.g., sorbent that is carbon dioxide free and, optionally, moisture free. Lean sorbent 1120 (e.g., as a solid or liquid) exits the desorber system 1128 and is recycled back to the adsorber system 1126. The lean sorbent 1120, in the filters of the adsorber system 1126, captures more atmospheric carbon dioxide from the ambient airflow input 1111. The demineralized water output 1116, typically, contains little to no carbon dioxide.

    [0575] FIG. 12 is a schematic illustration of an example implementation of an integrated power and carbon dioxide DAC system (integrated system) 1200. As illustrated, the integrated system 1200 includes a natural gas plant 1220 attached to a CCS flue gas carbon dioxide scrubber 1225 that generates waste heat 1202. The waste heat 1202 is supplied, in this example, to a thermal heat-reuse system 1210 that also utilizes a power input 1206. The thermal heat-reuse system 1210 provides a heated fluid 1204 to a carbon dioxide direct air capture (DAC) system 1215.

    [0576] A natural gas plant 1220 generates flue gas containing carbon dioxide and electrical power 1228 that is sent to the CCS flue gas carbon dioxide scrubber system 1225. The scrubber system 1225 separates out the carbon dioxide from the flue gas. The scrubber system 1225 provides waste heat 1202 to a carbon dioxide direct air capture (DAC) system 1215. The carbon dioxide DAC system 1215 also receives a power input 1208 and an ambient airflow input 1211. The carbon dioxide DAC system 1215 outputs a carbon dioxide supply stream 1212 and a carbon dioxide-reduced airflow output stream 1214.

    [0577] Generally, the integrated system 1200 operates to capture the waste heat 1202, generate the heated fluid 1204 that has a thermal energy that includes the waste heat 1202, as well as heat of compression from the thermal heat-reuse system 1210, and utilize such thermal energy in the heated fluid 1204 to separate carbon dioxide captured from the ambient airflow input 1211 to supply the separated carbon dioxide as the carbon dioxide supply stream 1212. In some aspects, the carbon dioxide supply stream 1212 can be provided as an injectant into a subterranean formation during hydrocarbon production operations. In some aspects, the injected carbon dioxide may be sequestered in the subterranean formation (with or without assisting in the hydrocarbon production operations).

    [0578] In this implementation, the industrial process 1205 is powered by the natural gas plant 1220 rather than the electrical power grid since the electrical power 1226 would be considered carbon negative electricity.

    [0579] The example thermal heat-reuse system 1210 utilizes the waste heat 1202 from the CCS Flue Gas CO.sub.2 Scrubber 1225 and power input 1206 to provide the heated fluid 1204. Generally, the thermal heat-reuse system 1210 includes one or more vapor -compression cycles (heat pumps) to add thermal energy in the form of heat of compression to the waste heat 1202 and transfer the sum of such energy to a fluid to generate the heated fluid 1204 (e.g., a heated liquid). Generally, each heat pump within the thermal heat-reuse system 1210 operates to transfer thermal energy from a heat sink to a heat source, i.e., in an opposite direction of spontaneous heat transfer. The one or more heat pumps of the thermal heat-reuse system 1210 use the power input 1206 to accomplish the work of transferring energy from the heat source to the heat sink. Each heat pump in the thermal heat-reuse system 1210 includes the primary components of two heat exchangers (one acting as an evaporator, one acting as a condenser), an expansion device (e.g., valve or fixed orifice), and a compressor (e.g., centrifugal, screw, reciprocating, scroll, or otherwise). Each of these components is fluidly coupled within a closed-loop refrigerant circuit in the heat pump.

    [0580] The carbon dioxide DAC system 1215, generally, operates to pass the ambient airflow input 1211 (which includes gaseous carbon dioxide) over or through one or more media (e.g., filters). In some aspects, one or more fans (not shown) utilize the power input 1208 to circulate the ambient airflow input 1211. The media or filter, in some aspects, includes a solid sorbent to which the atmospheric carbon dioxide in the airflow input 1211 bonds. The sorbent that is saturated with carbon dioxide may be referred to as rich sorbent.

    [0581] In the case of a solid sorbent, such as the sorbent described in the present disclosure, as the airflow input 1211 passes over the solid media or filter, atmospheric carbon dioxide within the input 1211 bonds to the media or filter. When the media or filter is saturated with carbon dioxide, it can be heated (e.g., to 100-120 C., to 60-100 C.) to release the carbon dioxide for collection (as described herein).

    [0582] Using thermal energy from the heated fluid 1204, heat is applied to the solid sorbent, which breaks the bonds between the carbon dioxide and the sorbent. The separated carbon dioxide is provided as the carbon dioxide output stream 1212 from the carbon dioxide DAC system 1215. The now-lean adsorbent that is carbon dioxide free (i.e., the solid or liquid) is recycled back to capture more carbon dioxide from the ambient airflow input 1211. The airflow output 1214, typically, contains little to no carbon dioxide. The carbon dioxide DAC system 1215 outputs carbon dioxide 1212 and demineralized water 1216.

    [0583] As further shown in the example embodiment of FIG. 12, the integrated system 1200 includes a power plant 1220 (e.g., a natural gas power plant 1220) and a scrubbing system 1225 (e.g., a CCS Flue Gas CO.sub.2 scrubbing system 1225). As shown in this example, the power plant 1220 may provide waste heat 1202 (e.g., as generated through the generation of electrical power by the power plant 1220) to the DAC system 1215. In this example, the power plant 1220 also generates electrical power 1222 and 1228. In some aspects, as shown, the electrical power 1222 goes through one or more switches 1230 (shown here as one, but more are possible) to provide electrical power 1224 to the DAC system 1215 and backup electrical power 1226 to the industrial process 1205.

    [0584] As shown in this example, the power output of the power plant 1220 may be sized to provide a sum of the electrical power 1224 to the DAC system 1215 and the electrical power 1228 to the scrubbing system 1225 for normal operation, as well as the backup electrical power 1226 to the industrial process 1205 when needed (i.e., when the industrial process 1205 loses or cannot use grid electrical power 1217). Thus, in some aspects, when the industrial process 1205 needs the backup electrical power 1226, electrical power 1228 and electrical power 1224 are still provided to their respective users. Alternatively, in some aspects, the power output of the power plant 1220 may be sized to provide a sum of the electrical power 1224 to the DAC system 1215 and the electrical power 1228 to the scrubbing system 1225 for normal operation, as well as the backup electrical power 1226 to the industrial process 1205 when needed (i.e., when the industrial process 1205 loses or cannot use grid electrical power 1217), as well as one or both of power inputs 1206 or 1208.

    [0585] Alternatively, in some aspects, the power output of the power plant 1220 may be sized only to provide the backup electrical power 1226 to the industrial process 1205 when needed (i.e., when the industrial process 1205 loses or cannot use grid electrical power 1217). Thus, during operational periods when the industrial process 1205 does not need backup electrical power 1226, the electrical power 1228 and/or the electrical power 1224 (as well as other power inputs).sub.may be provided by the power plant 1220. During operational periods when the industrial process 1205 does need backup electrical power 1226, the electrical power 1228 and/or the electrical power 1224 (as well as other power inputs).sub.may not be provided by the power plant 1220. For example, electrical power 1222 may be routed, in such operational periods, through the switch 1230 as backup electrical power 1226.

    [0586] In some aspects, the electrical power 1226 supplied from the power plant 1220 to the industrial process 1205 may not be backup power but instead may be a primary power source for the industrial process 1205. For example, in some aspects, the power plant 1220 may be sized to provide primary electrical power 1226 to the industrial process 1205, as well as, in some aspects, one or more other components shown in the integrated system 1200.

    [0587] As further shown in FIG. 12, in some aspects, waste heat 1202 that is generated from the scrubber system 1225 may be used by the thermal heat-reuse plant 1210 to provide heated fluid to the DAC system 1215. In some implementations, the heated fluid 1204 is then returned via heated fluid return 1213 to the thermal heat-reuse system 1210 and the waste heat 1202 is returned to the industrial process 1205 via waste heat return 1217.

    [0588] As shown in this example implementation, the scrubbing system 1225 also receives an exhaust fluid 1232 (e.g., the flue gas with 100% CO.sub.2) from the power plant 1220. For example, in some aspects, the power plant 1220 may be a natural gas power plant in which natural gas is combusted to drive electrical power generation equipment that operates to generate the electrical power shown in FIG. 12. In other aspects, the power plant 1220 may use other carbon-based fuel rather than natural gas. In still other aspects, the power plant 1220 may use non-carbon based fuels to generate electrical power (e.g., geothermal, solar, and other). For a natural gas power plant 1220, although not shown specifically here, such equipment may include, for example, a compressor rotatably coupled to a gas turbine that drives the compressor. The gas turbine receives combustion products fluid from a combustion chamber that receives compressed natural gas from the compressor. The combustion products fluid drives the gas turbine, which in turn is coupled to and drives a generator to produce electrical power.

    [0589] Output from such a gas turbine (at a lower pressure than the combustion products fluid) is exhaust fluid 1232 (e.g., as a flue gas). A difference in pressure between the combustion products fluid and the exhaust fluid 1232 drives the gas turbine to produce electrical power from the generator. As shown in this example, the exhaust fluid 1232 is separated by the scrubbing system 1225 into multiple output streams. For example, the flue gas with 100% CO.sub.2 1232 is separated into a carbon dioxide output and a flue gas stream 1236 with 5% CO.sub.2. The flue gas stream 1236 with 5% CO.sub.2 is sent to the DAC system 1215 to remove the remaining carbon dioxide from the output airflow of the natural gas plant 1220. This makes the resulting power generated from the natural gas plant carbon negative power. For example, similar to the DAC system 1215, outputs of a carbon dioxide supply stream 1212 and a carbon dioxide-reduced airflow output stream 1214 may be output from the scrubbing system 1225.

    [0590] In some aspects, the carbon dioxide supply streams 1212 may be sold (e.g., for CO.sub.2-EOR, sequestration, and/or other processes). For example, the carbon dioxide supply streams 1212 may generate revenue through emissions credits and federal tax credits. In some aspects, such revenue may offset capital and/or operations costs of the DAC system 1215, the power plant 1220, both, or other components of the system 1200.

    [0591] The integrated system 1200 may advantageously utilize the power plant 1220, which may normally be sitting idle, to produce a saleable product in the carbon dioxide fluid streams 1212, which also provide environmental benefits. Additionally, in the event of a power outage at the industrial process 1205, the power plant 1220 would already be running, meaning the delay between the outage and providing the process 1205 with power would be reduced. Further, by using the thermal energy 1202 from the waste heat 1202 from the scrubber 1225, operating costs of the DAC system 1215 may be significantly reduced, allowing for the carbon dioxide captured to finance the construction of the DAC system 1215 as well as help subsidize the cost of the industrial process's backup power. In addition, the integrated system 1200 may produce water from ambient humidity as the DAC system 1215 pulls carbon dioxide from the air. The water can be sold or used, e.g., at the industrial process 1205.

    [0592] In some embodiments, a DAC system comprises: a fluidized bed adsorption reactor configured to adsorb CO.sub.2 from ambient air using a sorbent material (e.g., any described herein); a desorption reactor configured to receive the sorbent material from the fluidized bed adsorption reactor and to desorb CO.sub.2 from the sorbent material; and an industrial process facility which produces waste heat that is provided to the desorption reactor to heat the sorbent material.

    [0593] In some embodiments, a DAC system comprises: a fluidized bed reactor or a silo adsorber configured to adsorb CO.sub.2 from ambient air using a sorbent material (e.g., any described herein). In some embodiments, the system further comprises a desorption system (e.g., a reactor, a desorber, a gravity fed desorption system, and the like) configured to receive the sorbent material from the fluidized bed reactor or the silo adsorber and to desorb CO.sub.2 from the sorbent material.

    [0594] In some embodiments, a DAC system comprises: a gravity fed desorption system configured to desorb CO.sub.2 from a sorbent material (e.g., any described herein). In some embodiments, the system further comprises an adsorption system (e.g., a reactor, an adsorber, a silo adsorber, and the like) configured to adsorb CO.sub.2 from ambient air using the sorbent material and configured to provide the sorbent material to the gravity fed desorption system.

    EXAMPLES

    Example 1Silane and Polymeric Amine Functionalized Porous Substrate for Carbon Capture

    [0595] Examples 1.1 to 1.3 generally relate to a functionalized porous silica and more specifically, to a functionalized porous silica for reversibly capturing carbon dioxide.

    Example 1.1N1-(3-Trimethoxysilylpropyl)diethylenetriamine and PEI Grafting

    [0596] In a three-necked round bottom flask, 4.85 g (80 mmol) of silica particles was added into 40 mL solvent (e.g., toluene, hexane, cyclohexane, and/or THF) at ambient temperature. The silica particles were stirred and soaked in the solvent for 2 hours. N1-(3-trimethoxysilylpropyl)diethylenetriamine, having the chemical formula:

    ##STR00045##

    was added into the above solution at a molar ratio in a range from 2.3 g to 4.7 g (e.g., 8 mmol to 16 mmol, e.g., a silica particle to amine material molar ratio in a range from 5:1 to 10:1). The mixture was heated and stirred at 60 C. or above (e.g., up to 90 C.). The temperature depends on the chosen solvent. The mixture was stirred for 18 hours (in some cases, the mixing continued for 24 hours). The mixture was cooled to room temperature. The functionalized silica particles were filtered from the solvent and washed twice while stirring with a 40 mL volume of solvent each time. The functionalized silica particles were dried in a vacuum oven at 50 C. for 12 hours. Alternatively, [3-(2-aminoethylamino)propyl]trimethoxysilane, having the chemical formula:

    ##STR00046##

    was added to the solution at 2.2 g to 4.5 g (e.g., 8 mmol to 16 mmol, e.g., a silica particle to amine material molar ratio in a range from 5:1 to 10:1).

    [0597] In a second round bottom flask, 30 mL of methanol or solvent mixture (e.g., cyclohexane:ethanol2:1), 5 g of silane-treated silica from the above step, and 1.5 g polyethylenimine (PEI) or other second amine (30 wt % to silica) was added. The mixture was stirred for 1 hour. The solvent was dried from the functionalized silica through evaporation, such as on a rotovap, to recover the functionalized silica. The functionalized silica particles were dried in a vacuum oven at 50 C. for 12 hours. The second step can be performed as a large scale process such as using vacuum drying together with an amine/solvent mixture spraying process.

    Example 1.2Bis[3-(trimethoxysilyl)propyl]amine Grafting

    [0598] Using a silane compound having two or more silane moieties (e.g., two trimethoxysilane or triethoxysilane functional groups) in the same molecule, such as for example bis[3-(trimethoxysilyl)propyl]amine, can facilitate a plurality of interactions between silane groups and silica, potentially improving binding stability of the silane bond to the silica surface.

    [0599] To add bis[3-(trimethoxysilyl)propyl]amine), having the chemical formula:

    ##STR00047##

    to the reaction, the same procedure as for [3-(2-aminoethylamino)propyl]trimethoxysilane grafting was followed.

    [0600] In a three-necked round bottom flask, 4.85 g (80 mmol) of silica particles was added into 40 mL solvent (e.g., toluene, hexane, cyclohexane, and/or THF) at ambient temperature. The silica particles were stirred and soaked in the solvent for 2 hours. [3-(2-aminoethylamino)propyl]trimethoxysilane, having the chemical formula:

    ##STR00048##

    was added into the above solution at 2.2 g to 4.5 g (e.g., 8 mmol to 16 mmol, e.g., a silica particle to amine material molar ratio in a range from 5:1 to 10:1). Bis[3-(trimethoxysilyl)propyl]amine) was added into the above solution at 0.68 g (e.g., 2 mmol, a silica particle to bisamine material ratio of 40:1). The mixture was heated and stirred at 60 C. or above (e.g., up to 90 C.). The temperature depends on the chosen solvent. The mixture was stirred for 18 hours. The mixture was cooled to room temperature. The functionalized silica particles were filtered from the solvent and washed twice while stirring with a 40 mL volume of solvent each time. The functionalized silica particles were dried in a vacuum oven at 50 C. for 12 hours.

    Example 1.3Experimental Results

    [0601] Functionalized silica produced using the processes described herein (e.g., in FIG. 3) was characterized by a CO.sub.2 uptake measurement (e.g., using a sample holder as illustrated in FIGS. 10A-10B). FIG. 14 is a line chart depicting CO.sub.2 uptake in mol CO.sub.2/kg (left y-axis) and against cycle number, e.g., the number of absorption and desorption cycles, (x-axis). The total CO.sub.2 uptake of the functionalized silica sample during a single desorption is indicated.

    Example 2CO.SUB.2 .Uptake Measurements for Functionalized Material

    [0602] Functionalized silica produced using the processes described herein (e.g., process 300 illustrated in FIG. 3) were characterized by a CO.sub.2 uptake measurement. FIG. 10A schematically illustrates an exploded view (left) and an assembled view (right) of the sample holder 1000 for a sorbent. Functionalized silica particles or granules were placed in a sample space 1006 arranged between two layers of filter 1004 (e.g., such as glass wool) in a sample holder 1000. The sealing ends 1002 of the sample holder 1000 included an inlet 1008 and an outlet 1010 permissive to gas flow. The sealing ends 1002 included reversible screw connections to assemble the sample holder 1000. When assembled (right), the sample holder 1000 was otherwise sealed against gaseous inflow.

    [0603] In FIG. 10B, a schematic diagram of the experimental setup 1020 is shown. Referring now to FIGS. 10A and 10B, a gas source, e.g., air compressor 1022, provided compressed environmental air to the inlet 1008 of a testing sample holder 1000, which was then passed through the filters 1004 and exposed the functionalized silica to environmental air. Optionally, air was exhausted from the outlet 1010. The concentration of CO.sub.2 in the compressed environmental air was measured by a gas analyzer, e.g., CO.sub.2 gas analyzers 1024 and 1026, prior to entering the inlet 1008 and/or subsequent to exiting the outlet 1010.

    [0604] The samples of functionalized silica were treated with an activation process before data collection. Samples were heated in a vacuum drier (e.g., vacuum heater 1028) to 70 C. for 30 minutes under vacuum (e.g., 0.3 psi) to activate the adsorbent, e.g., as the activation process. Alternatively, and as shown in FIG. 10B, the heating element and the vacuum system 1030 were separate elements of the setup 1020 and worked in concert to heat and apply vacuum to the sample holder 1000. In some implementations, a cooling element 1032 was included in the setup 1020 to further control the temperature of the environment in the sample holder 1000. The activation process facilitated removal, e.g., evaporation, of residual solvent medium in the pores of the functionalized silica and facilitated desorption of CO.sub.2 molecules bonded during a synthesis process (e.g., process 300) for venting to the atmosphere.

    [0605] For the adsorption procedure, samples of functionalized silica in a range between 0.5 g and 10 g were placed in between two layers of glass fiber filters 1004 in the testing sample holder 1000. Compressed environmental air (e.g., input air) from gas source 1022 were continuously fed through the testing sample holder 1000 at a rate 1 to 10 standard liters per minute (slpm), thereby exposing the activated functionalized silica. The activated functionalized silica was exposed for time periods 30 to 60 minutes. The humidity of the input air was controlled to be 15% to 50% RH at 21 C. The same sample holder was then brought to vacuum by vacuum system 1030 and heated by vacuum heater 1028 to extract the carbon dioxide from the sample.

    [0606] The amount of carbon dioxide extracted was measured by gas analyzer 1026. The humidity was controlled through blending of dry air and wet air with a flow meter (not shown). As an example, to produce input air having 50% RH at a flow rate of 5 slpm, dry air (e.g., <10% RH) at 2.5 slpm and wet air (e.g., >95% RH, 100% RH) was blended at 2.5 slpm each. The dry air and wet air flow control was performed using a closed loop controller.

    [0607] The compressed environmental air including CO.sub.2 concentration was monitored by gas analyzers 1024 and 1026 at the input and output of the testing sample holder 1000 during the experimental time period in units of mol CO.sub.2/kg of adsorbent.

    Example 3Agglomeration Trials for Functionalized Material

    [0608] Shown below in Tables 1 and 2 are two trials in which fine particles were agglomerated to a baseline silica to form recycled silica particles. The CO.sub.2 uptake (mol/kg), attrition loss (wt %), crush strength (MPa), and/or bulk density (g/L) were determined.

    [0609] A baseline raw silica product was used as a base for the agglomerated particles. The CO.sub.2 uptake of the baseline raw silica was determined using methods described herein to determine a normalized uptake with which to compare the agglomerated samples.

    [0610] The agglomerated samples were formed as described herein using the baseline silica. The agglomerated samples of Table 1 were agglomerated using dry roller compaction under a pressure according to the specific row, e.g., either 20 kilopounds per square inch (ksi) or 30 ksi. In the Condition column, the term Milled means the baseline material was less than 100 microns in size. The term Non-milled means the baseline material was up to 500 microns.

    [0611] Attrition testing was performed on the agglomerated samples. Briefly, 100 g of each sample was placed in a sieve shaker using a 20 mesh screen. The samples were agitated in the shaker for 5 minutes using a tapper. 50 g of the plus 20 mesh product was placed on the mesh 20 screen. 50 pieces of 9.5 mm ceramic beads were added to the 20 mesh screen. The samples were agitated for 5 minutes without the tapper. The weight percentage of fines found in the base pan following the agitation with the ceramic beads was determined compared to the original sample.

    [0612] Following agglomeration, the samples were coated with the functionalization mixture and tested for CO.sub.2 uptake, both methods as described herein. Briefly, for the functionalization/coating process, 7.7 wt % of PEI and 36 wt % of DAMO in 160 wt % of water were added to 100 g of the silica substrate by dip coating in the PEI/DAMO/Water solution. After the dip coating, the samples were dried under vacuum at 70 C. for 24 hrs. The samples were tested with the method described in Examples 1 and 2 to determine the uptake performance.

    TABLE-US-00001 TABLE 1 Uptake Attri- Trial 1 Condition Shape (mol/kg) tion Baseline Not from agglomeration Spherical 1.2 8.7% Silica granules BT1 Run1 Silica150A no-milled Flat chips 1.14 30.5% 20 ksi (70-200 um) BT1 Run2 Silica 150A milled 20 ksi Flat chips 0.67 6.9% BT1 Run3 Silica 150A milled 30 ksi Flat chips 0.53 7.7% BT1 Run4 Silica F1 milled 20 ksi Flat chips 0.64 11.3%

    [0613] The agglomerated samples for Table 2 (below) were produced using a liquid binding mixture of PVA and water at varying wt % (PVA to water wt %) as a binder. The samples from Table 2 were agglomerated using a mixer with the liquid binding mixture.

    [0614] The CO.sub.2 uptake capacity and attrition were determined using the same method as for the samples for Table 1. The agglomerated particles for Table 2 were characterized for compression strength. The bulk compression strength test utilizes a test fixture that consists of a lower crush platform and upper crusher head. The lower crush platform included a flat surface onto which samples are placed. The upper crush head included a crush head with a flat lower surface substantially parallel with the plane of surface such that force was applied evenly to particles between the crush head and surface during force application. The crush head had an outer diameter (OD) 72.6 mm and the surface was 124.5 mm in diameter. The crush platform had a diameter 125.4 mm. In another example, the crush platform had a diameter of 146 mm.

    [0615] During testing, a layer of particles, e.g., the sample, was packed closely on the crush platform and roughly aligned with the center of the crush head. The particle bed diameter was about 90 mm to about 2 mm in thickness. The samples were 3-6 g dry weight depending on particle coating components. The force applied to the crush head was recorded while displacement changed. The packed particle bed was crushed to achieve 50% of its compressive strain (e.g., displacement divided by initial sample bed thickness) and the stress (MPa) (e.g., force divided by contact area) is reported as 50% strain crush strength. Samples of uncoated, and coated particles were tested. For both types of particle, at least 3 samples were tested to get the average performance for the bulk compression strength.

    [0616] The bulk density was measured according to ASTM D1895 Method A. Briefly, fine granules were poured through a V shaped funnel. The material being tested were allowed to flow into a cylinder cup with a known volume of 100 mL. Testing results were averaged using more than 4 measurements.

    TABLE-US-00002 TABLE 2 Crush Bulk Uptake Strength Density Trial 2 Condition Shape (mol/kg) Attrition (MPa) (g/L) Baseline Not from Spherical 1.2 12% 1.14 260 Silica agglomeration granules BT1 7% PVA solution 1.35 5-7 wt % 1.04 262 Run1 as binder BT1 10% PVA solution 1.3 5-7 wt % 1.21 268 Run2 as binder BT1 3% PVA solution 1.35 5-7 wt % 0.87 255 Run3 as binder

    Example 4Experimental Results of Uncoated and Coated Functionalized Material

    [0617] Functionalized, coated particles produced using the process 300 described herein were characterized for compression strength and attrition resistance. The bulk compression strength test utilized the test fixture 1500 shown in FIG. 15. The test fixture 1500 consisted of a lower crush platform 1502 and upper crusher head 1506. The lower crush platform 1502 included a flat surface 1512 onto which samples are placed. The upper crush head 1506 included a crush head 1516 with a flat lower surface substantially parallel with the plane of surface 1512 such that force was applied evenly to particles between the crush head 1516 and surface 1512 during force application. The crush head 1516 had an outer diameter (OD) 72.6 mm and the surface 1512 was 124.5 mm in diameter. The crush platform 1502 had a diameter 125.4 mm. In another example, the crush platform had a diameter of 146 mm.

    [0618] During testing, a thin layer of particles, e.g., the sample, was packed closely on the crush platform 1502 and roughly aligned with the center of the crush head 1516. The particle bed diameter was 90 mm and about 2 mm in thickness. The samples were in a range from 3-6 g dry weight depending on particle coating components. The force applied to the crush head 906 was recorded while displacement changed. The packed particle bed was crushed to achieve 50% of its compressive strain (e.g., displacement divided by initial sample bed thickness) and the stress (MPa) (e.g., force divided by contact area) was reported as 50% strain crush strength. Samples of uncoated, and coated particles were tested. For both types of particle, at least 3 samples were tested to get the average performance for the bulk compression strength.

    [0619] Table 3 presents the bulk compression strength for the samples. Compression strength is also known as crush strength. Samples included no coating raw porous substrate, silica coated with amine only, and silica coated with various types of polymers. The particles of each sample had average radii in a range from 1 to 1.4 mm to ensure consistent particle size distribution.

    TABLE-US-00003 TABLE 3 Bulk Compression Strength Results. 50% Strain Compressive Normalized Strength % to Sample (MPa) Control Control No coating 1.29 100% 1 Amine coating 1.36 105% 2 Amine coating + 200K Mw PVA 2.09 162% 3 Amine coating + 30-50K Mw PVA 2.05 159% 4 Amine coating + 13-23K Mw PVA 1.73 134% 5 Amine coating + cellulose acetate 1.40 108% 6 Amine coating + PVP 1.59 123% 7 Amine coating + PVA 99% 1.77 137% Hydrolyzed

    [0620] PVA reinforcement (Sample 2) improved the crush strength by 162% (maximum) compared to baseline raw silica. Different molecular weight PVA resulted in different reinforcement effects. Lower molecular weight PVA (Sample 4) showed less reinforcement effect compared to Sample 2, e.g., the normalized improvement was about 134%. Other polymers such as cellulose acetate, PVP also provided a reinforcement effect. Cellulose acetate reinforcement (Sample 5) provided 108% reinforcement and PVP (Sample 7) provided 137% reinforcement. A bar chart of the compression strength results comparison is shown in FIG. 10.

    [0621] Attrition and abrasion resistance was determined according to the ASTM D4058-96 (Standard Test Method for Attrition and Abrasion of Catalysts and Catalyst Carriers) testing method. The testing fixture 1600 is shown in FIG. 16A and exploded diagram of the drum 1602 is shown in FIG. 16B. Samples of particles were placed inside the drum 1602 and the testing fixture 1600 rotated the drum 1602 for a 30 minute cycle. The particles within the drum 1602 interacted with a baffle 1604 that caused attrition loss. As the particles are tumbled, attrition occurred. The sample of particles were removed and the particles sieved to determine loss to attrition. Attrition is the process of breaking down, therefore loss to attrition refers to the amount of particles that have broken down to a standard definition. In the process described herein, particles broken down to <0.5 mm are no longer useful and will be collected, e.g., filtered, and discarded and would be defined as lost to attrition. Table 4 shows the results.

    TABLE-US-00004 TABLE 4 Attrition Loss Results Reduction in generated fines (%) particle particle particle particle Single cycle attrition size > size > size > size > (% loss) 0.71 mm 0.1 mm 0.71 mm 0.1 mm Raw silica 1.65% 1.33% PVA coated silica 0.91% 0.89% 45% 33% test 1 PVA coated silica 1.05% 1.04% 36% 22% test 2 PVA and amine 0.93% 0.93% 44% 30% coated silica

    [0622] As shown in Table 4, particles including the polymer reinforcement coating had improvement on the attrition loss resistance of between 36%-45% for particle size<0.71 mm.

    Example 5Sorbent Formulation

    [0623] This example provides a method of forming a plurality of functionalized crosslinked particles. In step 1, a plurality of porous particles were introduced to a third reagent comprising a polymer, thereby coating the plurality of porous particles. Then, in step 2, at least a portion of the surface of each of the coated porous particle in at least a subset of a plurality of porous particles was introduced to (i) a crosslinking agent and (ii) a first reagent comprising at least one adsorbing moiety. Further in step 2, the at least the portion of the surface of each porous particle in at least the subset of a plurality of porous particles was introduced to a second reagent comprising at least one interaction moiety and an antioxidant.

    [0624] In this example the plurality of porous particles were silica particles.

    [0625] In this example the polymer in the third reagent was 13K-23K MW polyvinylalcohol (PVA). The third reagent also included the chelating agent etridonic acid.

    [0626] In this example the at least one adsorbing moiety of the first reagent was the polyamine poly(ethyleneimine) (PEI).

    [0627] In this example the at least one interaction moiety of the second reagent was the aminosilane aminopropyltrimethoxysilane (DAMO).

    [0628] In this example the crosslinking agent was the dialdehyde terephthalaldehyde (TALD).

    [0629] In this example the antioxidant was Chimassorb 944 FDL (C.sub.944) (Poly [[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][imino (2,2,6,6-tetramethyl-4-piperidinyl)]-1,6-hexanediylimino (2,2,6,6-tetramethyl-4-piperidinyl)]]; BASF, Ludwigshafen am Rhein, 67056

    Germany).

    Step 1.

    [0630] Formation of third reagent. Slowly 15 g of 13-23K Mw PVA was charged into 60 mL of rapidly stirring cold water in a 500 mL flask with a condenser. The mixture was heated to 70-80 C. and stirred till a homogeneous solution was obtained, approximately 30 minutes. The solution was cooled to 60-70 C. under constant stirring. Slowly, 140 mL of hot ethanol (60 C.) was charged into the flask and mixed thoroughly till a uniform solution was obtained. 1.67 g of 60% etidronic acid (ETDA) solution was charged into the warm solution (50-60 C.) and mixed thoroughly till a uniform solution was obtained.

    [0631] Introducing a plurality of porous particles to the third reagent. The warm PVA-ETDA-ethanol-water solution was decanted over 100 g of silica in a 1 L rotary evaporation flask with mixing. The flask was placed on the rotary evaporator and set to 20 rotations per minute (rpm) till the mixture was observed to be homogenous with no dry particles. Once a uniform mixture was obtained the rotary evaporator was set to 70 C., 50 mbar, and 10 rpm. The mixture was dried till the sorbent contained 20-30 wt % volatiles as measured by a Mettler Toledo Halogen Moisture Analyzer HE73.

    Step 2.

    [0632] The PVA-ETDA-coated silica product from step 1 (141 g) was left in the 1 L rotary evaporator flask.

    [0633] Formation of a first and second reagent comprising at least one adsorbing moiety, at least one interaction moiety, crosslinking reagent, and antioxidant.

    [0634] 10 g of PEI (the adsorbing moiety) and 45 g of DAMO(the interaction moiety) was charged into a 500 mL beaker followed by 10 mL isopropyl alcohol (IPA). The PEI, DAMO, and IPA were mixed till a uniform solution was obtained.

    [0635] 1.1 g terephthalaldehyde (TALD) (the crosslinking agent) having the chemical structure:

    ##STR00049##

    was charged into a 250 mL beaker followed by 141 mL of hexane and 19 mL of IPA. 1 g Chimassorb 944 FDL (C944) (the antioxidant) was charged into the same 250 ml beaker and mixed till a uniform solution was obtained. The TALD-C944-hexane-IPA was warmed to 60 C. with mixing till a uniform solution was obtained.

    [0636] The DAMO-PEI-IPA solution was warmed to 40 C. with mixing. The warm TALD-C944-hexane-IPA solution was charged into the 500 ml beaker of DAMO-PEI-IPA. The temperature was maintained at 60 C. and mixed till a homogeneous solution was obtained.

    [0637] Introducing at least a portion of the surface of each of the coated porous particle in at least a subset of the plurality of coated porous particles to (i) a crosslinking agent, (ii) at least one adsorbing moiety, (iii) at least one interaction moiety, and (iv) an antioxidant. The warm PEI-DAMO-TALD-C944-Hexane -IPA solution was decanted over the 141 g of PVA-ETDA-coated silica product from step 1 in the 1 L rotary evaporation flask with mixing. The flask was placed on the rotary evaporator and spun at 20 rpm till the mixture was observed to be uniform. Once a uniform mixture was obtained, the rotary evaporator was set to 70 C., 50 mbar, and 10 rpm. The mixture was dried till the sorbent contained <5 wt % volatiles as measured by a Mettler Toledo Halogen Moisture Analyzer HE73.

    Example 6Procedures for Crosslinking with a Dialdehyde Crosslinker

    [0638] This example provides a method of forming a plurality of functionalized crosslinked particles. The method comprises introducing at least a portion of the surface of each porous particle in at least a subset of a plurality of porous particles to (i) a crosslinking agent and (ii) a first reagent comprising at least one adsorbing moiety. The method further comprises introducing the at least the portion of the surface of each porous particle in at least the subset of the plurality of porous particles to a second reagent comprising at least one interaction moiety.

    [0639] In this example the plurality of porous particles were silica particles.

    [0640] In this example the at least one adsorbing moiety of the first reagent was the polyamine poly(ethyleneimine) (PEI).

    [0641] In this example the at least one interaction moiety of the second reagent was the aminosilane aminopropyltrimethoxysilane (DAMO).

    [0642] In this example the crosslinking agent was the dialdehyde terephthalaldehyde (TALD).

    [0643] 10 g of dry beaded silica sorbent previously coated with 7.7 wt % polyethylenimine (PEI) and 36 wt % N-2-Aminoethyl-3-aminopropyltrimethoxysilane (DAMO) were charged into a solution containing 2 wt % T-ALD crosslinking agent relative to the sorbent mass dissolved in 10 mL 1:1 Hexane:IPA. The solution-silica mixture stirred until the silica was entirely wetted with no excess solvent visible and subsequently heated in a vacuum oven at 90 C. and 50 mbar for 12 hours. Table 5 below compares dry beaded silica sorbent previously coated with 7.7 wt % polyethylenimine (PEI) and 36 wt % N-2-Aminoethyl-3-aminopropyltrimethoxysilane (DAMO) to particles further treated with the T-ALD.

    TABLE-US-00005 TABLE 5 Crosslinker Group None Aldehyde Crosslinker N/A p-terephthaldehyde Crush Strength (N) 7.45 8.05 Uptake (mol/kg) 0.79 0.68

    [0644] Crush strength (N) was average single particle crush strength from 30 samples. The testing was done with Instron compression mode with constant displacement control (0.5 mm/minute strain rate) till the particle breaks. The testing fixture includes a platen and a compression pin. The plate was fixed on the Instron. A single sorbent particle was placed on the plate. The compression pin had a round flat contact surface with diameter 1 cm (>>single particle size). During the testing, the compression pin was pushed to the particle with a constant speed of 0.5 mm/min until the particle breaks. The contacting force was recorded by the Instron load cell. The crush strength was the peak force before the particle breaks.

    [0645] Uptake was measured with a home-made breakthrough instrument. The sorbent was packed in a packed bed with thickness 3 mm. Compressed environment air was fed through the sorbent at a constant flow rate. The CO.sub.2 concentration in the air feed in the sorbent and flow out of the sorbent was measured with an IR CO.sub.2 measuring device. Enough run time was given to allow the sorbent to be fully saturated. The uptake was calculated based on the breakthrough measurement. Table 5 shows that the addition of crosslinker improves the crush test performance without substantial expense on CO.sub.2 update.

    Example 7Procedures for Crosslinking with a Diacrylate Crosslinker

    [0646] This example provides a method of forming a plurality of functionalized crosslinked particles. The method comprises introducing at least a portion of the surface of each porous particle in at least a subset of a plurality of porous particles to (i) a crosslinking agent and (ii) a first reagent comprising at least one adsorbing moiety. The method further comprises introducing the at least the portion of the surface of each porous particle in at least the subset of the plurality of porous particles to a second reagent comprising at least one interaction moiety.

    [0647] In this example the plurality of porous particles were silica particles.

    [0648] In this example the at least one adsorbing moiety of the first reagent was the polyamine poly(ethyleneimine) (PEI).

    [0649] In this example the at least one interaction moiety of the second reagent was the aminosilane aminopropyltrimethoxysilane (DAMO).

    [0650] In this example the crosslinking agent was a diacrylate crosslinker.

    [0651] 10 g of dry beaded silica sorbent previously coated with 7.7 wt % PEI and 36 wt % N-DAMO were charged into a solution containing 5 wt % diacrylate crosslinking agent relative to the sorbent mass dissolved in 10 mL 1:1 Hexane:IPA. The solution-silica mixture stirred until the silica was entirely wetted with no excess solvent visible and subsequently heated in a vacuum oven at 90 C. and 50 mbar for 12 hours.

    TABLE-US-00006 TABLE 6 Crosslinker Group Acrylate Crosslinker N/A Proprietary Proprietary 1,6- Polyethylene urethane aliphatic Hexanediol Glycol 600 acrylate urethane Diacrylate Diacrylate oligomer acrylate Crush 7.45 6.68 7.31 9.72 9.57 Strength (N) Uptake 0.79 0.71 0.73 0.65 0.71 (mol/kg)

    [0652] Crush strength and uptake were as described in Example 6. Table 6 shows that the addition of the 1,6-hexanediol diacrylate and the polyethylene glycol 600 crosslinker improves the crush test performance without substantial expense on CO.sub.2 update.

    Example 8Procedures for Crosslinking with an Epoxy Crosslinker

    [0653] This example provides a method of forming a plurality of functionalized crosslinked particles. The method comprises introducing at least a portion of the surface of each porous particle in at least a subset of a plurality of porous particles to (i) a crosslinking agent and (ii) a first reagent comprising at least one adsorbing moiety. The method further comprises introducing the at least the portion of the surface of each porous particle in at least the subset of the plurality of porous particles to a second reagent comprising at least one interaction moiety.

    [0654] In this example the plurality of porous particles were silica particles.

    [0655] In this example the at least one adsorbing moiety of the first reagent was the polyamine poly(ethyleneimine) (PEI).

    [0656] In this example the at least one interaction moiety of the second reagent was the aminosilane aminopropyltrimethoxysilane (DAMO).

    [0657] In this example the crosslinking agent was an diepoxy crosslinker.

    [0658] 10 g of dry beaded silica sorbent previously coated with 7.7 wt % PEI and 36 wt % N-DAMO were charged into a solution containing 5 wt % diepoxide crosslinking agent relative to the sorbent mass dissolved in 10 mL 1:1 Hexane:IPA. The solution-silica mixture stirred until the silica was entirely wetted with no excess solvent visible and subsequently heated in a vacuum oven at 80 C. and 50 mbar for 12 hours.

    TABLE-US-00007 TABLE 7 Crosslinker Group Epoxy Crosslinker N/A polyethylene 1,4- polyethylene glycol diglycidyl butanediglycidyl glycol diglycidyl ether ether Crush Strength 7.45 15.05 10.15 11.28 (N) Uptake (mol/kg) 0.79 0.50 0.60 0.67

    [0659] Crush strength and uptake were as described in Example 6. Table 7 shows that the addition of the epoxy crosslinker improves the crush test performance without substantial expense on CO.sub.2 update.

    Example 9Procedures for Crosslinking with an Isocyanate Crosslinker

    [0660] This example provides a method of forming a plurality of functionalized crosslinked particles. The method comprises introducing at least a portion of the surface of each porous particle in at least a subset of a plurality of porous particles to (i) a crosslinking agent and (ii) a first reagent comprising at least one adsorbing moiety. The method further comprises introducing the at least the portion of the surface of each porous particle in at least the subset of the plurality of porous particles to a second reagent comprising at least one interaction moiety.

    [0661] In this example the plurality of porous particles were silica particles.

    [0662] In this example the at least one adsorbing moiety of the first reagent was the polyamine poly(ethyleneimine) (PEI).

    [0663] In this example the at least one interaction moiety of the second reagent was the aminosilane aminopropyltrimethoxysilane (DAMO).

    [0664] In this example the crosslinking agent was a blocked isocyanate crosslinker.

    [0665] 10 g of dry beaded silica sorbent previously coated with 7.7 wt % PEI and 36 wt % N-DAMO were charged into a solution containing 5 wt % blocked isocyanate crosslinking agent relative to the sorbent mass dissolved in 10 mL 1:1 Hexane:IPA. The solution-silica mixture stirred until the silica was entirely wetted with no excess solvent visible and subsequently heated in a vacuum oven at 80 C. and 50 mbar for 12 hours.

    TABLE-US-00008 TABLE 8 Crosslinker Group Blocked Isocyanate Crosslinker N/A Aliphatic blocked HDI Aliphatic blocked HDI biuret isocyanate biuret isocyanate Recipe Name Baseline No Trixene_BI_7960 Trixene_BI_7961 Crosslinker Crush Strength (N) 7.45 10.17 9.97 Uptake (mol/kg) 0.79 0.67 0.73

    [0666] Crush strength and uptake were as described in Example 6. Table 8 shows that the addition of the blocked isocyanate crosslinker improves the crush test performance without substantial expense on CO.sub.2 update. In Table 8 Trixene BI 7960 and Trixene B1 7961 are from Baxenden Chemicals Ltd., Lancashire, United Kingdom.

    Example 10Procedures for Crosslinking with an Acid Chloride Crosslinker

    [0667] This example provides a method of forming a plurality of functionalized crosslinked particles. The method comprises introducing at least a portion of the surface of each porous particle in at least a subset of a plurality of porous particles to (i) a crosslinking agent and (ii) a first reagent comprising at least one adsorbing moiety. The method further comprises introducing the at least the portion of the surface of each porous particle in at least the subset of the plurality of porous particles to a second reagent comprising at least one interaction moiety.

    [0668] In this example the plurality of porous particles were silica particles.

    [0669] In this example the at least one adsorbing moiety of the first reagent was the polyamine poly(ethyleneimine) (PEI).

    [0670] In this example the at least one interaction moiety of the second reagent was the aminosilane aminopropyltrimethoxysilane (DAMO).

    [0671] In this example the crosslinking agent was an acid chloride crosslinker.

    [0672] 10 g of dry beaded silica sorbent previously coated with 7.7 wt % PEI and 36 wt % N-DAMO were charged into a solution containing 2.5 wt % terephthaloyl chloride crosslinking agent relative to the sorbent mass dissolved in 10 mL tetrahydrofuran (THF). The solution-silica mixture stirred until the silica was entirely wetted with no excess solvent visible and subsequently heated in a vacuum oven at 80 C. and 50 mbar for 12 hours.

    TABLE-US-00009 TABLE 9 Crosslinker Group Acid Chloride Crosslinker N/A terephthaloyl chloride Crush Strength (N) 7.45 7.20 Uptake (mol/kg) 0.79 0.16

    [0673] Crush strength and uptake were as described in Example 6.

    Example 11Procedures for Crosslinking with an Alkyl Bromide Crosslinker

    [0674] This example provides a method of forming a plurality of functionalized crosslinked particles. The method comprises introducing at least a portion of the surface of each porous particle in at least a subset of a plurality of porous particles to (i) a crosslinking agent and (ii) a first reagent comprising at least one adsorbing moiety. The method further comprises introducing the at least the portion of the surface of each porous particle in at least the subset of the plurality of porous particles to a second reagent comprising at least one interaction moiety.

    [0675] In this example the plurality of porous particles were silica particles.

    [0676] In this example the at least one adsorbing moiety of the first reagent was the polyamine poly(ethyleneimine) (PEI).

    [0677] In this example the at least one interaction moiety of the second reagent was the aminosilane aminopropyltrimethoxysilane (DAMO).

    [0678] In this example the crosslinking agent was 1,4-bis(bromomethyl)benzene.

    [0679] 10 g of dry beaded silica sorbent previously coated with 7.7 wt % PEI and 36 wt % N-DAMO were charged into a solution containing 3.3 wt % 1,4-bis(bromomethyl)benzene crosslinking agent relative to the sorbent mass dissolved in 10 mL tetrahydrofuran (THF). The solution-silica mixture stirred until the silica was entirely wetted with no excess solvent visible and subsequently heated in a vacuum oven at 80 C. and 50 mbar for 12 hours.

    TABLE-US-00010 TABLE 10 Crosslinker Group Alkyl Bromide Crosslinker N/A alpha alpha dibromo-xylene Crush Strength (N) 7.45 8.32 Uptake (mol/kg) 0.79 0.68

    [0680] Crush strength and uptake were as described in Example 6. Table 10 shows that the addition of the alkyl bromide crosslinker improves the crush test performance without substantial expense on CO.sub.2 update.

    Example 12Procedures for Crosslinking with a Dianhydride Crosslinker

    [0681] This example provides a method of forming a plurality of functionalized crosslinked particles. The method comprises introducing at least a portion of the surface of each porous particle in at least a subset of a plurality of porous particles to (i) a crosslinking agent and (ii) a first reagent comprising at least one adsorbing moiety. The method further comprises introducing the at least the portion of the surface of each porous particle in at least the subset of the plurality of porous particles to a second reagent comprising at least one interaction moiety.

    [0682] In this example the plurality of porous particles were silica particles.

    [0683] In this example the at least one adsorbing moiety of the first reagent was the polyamine poly(ethyleneimine) (PEI).

    [0684] In this example the at least one interaction moiety of the second reagent was the aminosilane aminopropyltrimethoxysilane (DAMO).

    [0685] In this example the crosslinking agent was s-BPDA (3,3,4,4-biphenyltetracarboxylic dianhydride).

    [0686] 10 g of dry beaded silica sorbent previously coated with 7.7 wt % PEI and 36 wt % N-DAMO were charged into a solution containing 3.7 wt % s-BPDA crosslinking agent relative to the sorbent mass dissolved in 10 mL 1:1 methanol:THF. The solution-silica mixture stirred until the silica was entirely wetted with no excess solvent visible and subsequently heated in a vacuum oven at 80 C. and 50 mbar for 12 hours.

    TABLE-US-00011 TABLE 11 Crosslinker Group Anhydride Crosslinker N/A 3,3,4,4-biphenyltetracarboxylic dianhydride Crush Strength (N) 7.45 7.20 Uptake (mol/kg) 0.79 0.05

    [0687] Crush strength and uptake were as described in Example 6.

    CONCLUSION

    [0688] Embodiments of the subject matter and the operations described in this specification (e.g., for any system herein, such as a DAC system, a fluidized bed reactor, a silo adsorber, a gravity fed desorption system, as well as combinations and subcombinations thereof) can be implemented, in part, by digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them, in additional to the structures described herein.

    [0689] A computer storage medium can be, or be included in, a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination of one or more of them. Moreover, while a computer storage medium is not a propagated signal, a computer storage medium can be a source or destination of computer program instructions encoded in an artificially-generated propagated signal.

    [0690] The operations described in this specification can be implemented as operations performed by a data processing apparatus on data stored on one or more computer-readable storage devices or received from other sources. The term data processing apparatus encompasses all kinds of apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, a system on a chip, or multiple ones, or combinations, of the foregoing.

    [0691] The separation of various system modules and components in the embodiments described herein (e.g., for any system herein) should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. In certain circumstances, multitasking and parallel processing may be advantageous.

    [0692] While this specification contains many details, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of features specific to particular examples. Certain features that are described in this specification in the context of separate implementations can also be combined. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple embodiments separately or in any suitable subcombination.

    [0693] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other implementations are within the scope of the following claims.