The present invention refers to a surface coating of commercial polyamide (PA) membranes with graphene oxide (GO) using a technology that involves spin-coating with specific sequence of low and high rotation, interface phenomena provided by a set of materials containing ethyl alcohol in high concentration, as well as morphological characteristics and customized surface chemistry of GO, among other conditions that allow a differentiated technology to obtain an effective coating of GO on PA membrane.

Apparatuses and methods for fabricating thin film composite hollow fiber membranes. In some implementations, an apparatus is used to remove excess first solution from a hollow fiber that has been immersed in a first solution. In some implementations, the method and apparatuses include flowing a gas, for example, compressed gas or ambient air, past a surface of a hollow fiber that has been immersed in a first solution prior to immersion in a second solution. In some implementations, the gas is flowed past the surface under positive pressure, while in other implementations the gas is flowed under negative pressure, for example, vacuum. The apparatuses and devices can be used to produce thin film composite hollow fiber membranes without pressing or damaging the hollow fiber.

Novel low-pressure nanofiltration membrane composites for rejecting organic compounds are prepared by interfacial polymerization on a microporous hollow fiber supporting membrane. The interfacial polymerization reaction is carried out using an essentially monomeric polyamine reactant having at least two amine functional groups per molecule, and an essentially monomeric amine-reactive polyfunctional aromatic or cycloaliphatic acyl halide having at least two acyl halide groups per molecule. The composite can be fabricated by stepwise polymerization reactions with different reactant recipes at each step.

A method for the repair of defects in a graphene or other two-dimensional material through interfacial polymerization.

A method for making metal organic frameworks (MOFs) includes the step of dissolving metal salts in deionized water to form first solution, followed by adding a cyclic propyl phosphonic anhydride reagent to the first solution to form a second solution. The second solution is heated to form a reaction mixture containing MOF crystals, and is then cooled. The MOF crystals are filtered therefrom, washed and dried. To make metal organic framework-based thin film nanocomposite membranes, the MOF crystals are mixed with an m-phenylene diamine aqueous solution to form a mixture, which is then poured on a top surface of an ultrafiltration membrane substrate to form a first intermediate membrane structure. The first intermediate membrane structure is dried, and trimesolyl chloride in n-hexane solution is poured thereon to form a second intermediate membrane structure, which is cured to form an MOF-based thin film nanocomposite membrane, which is then rinsed and dried.

A hand-carry gravity-driven water filter with high throughput and water disinfection performance is formed. Membranes used for this water filter can be fabricated using electrospun method and non-solvent induced phase inversion method. A novel composite membrane structure (interwoven composite structure) was designed for further enhances water permeability and mechanical strength. The composite membrane can be composed of nanofibers with different diameter from the same polymer or different polymers. Membrane porosity and surface pore size can be controlled. Silver nanoparticles can be in-situ loaded on the surface of the membranes. The developed filter is effective for removal of a wide range of contaminants (e.g., pathogens, suspended solids and heavy metals). The purification process can be carried out under the drive of gravity (with an option for mechanically-enhanced filtration) without electricity.

A hydrophobic-oleophilic and hollow fiber composite membrane includes hollow tubular braids and surface separation layers coated on the outer surfaces of the hollow tubular braids. Membrane-forming polymers in the surface separation layers are polyvinylidene fluoride, and all other components are hydrophobic ingredients, including graphene. A preparing method includes preparing hollow tubular braids by two-dimensional braided technique using polyester filaments, wherein the hollow tubular braids are used as the reinforcements. The method further includes mixing polyvinylidene fluoride, hydrophobic pore-forming agent, and the rest of solvent to prepare a casting solution of surface separation layer. The method further includes pre-treatment processing of the reinforcements; and coating the casting solution of surface separation layer on the outer surface of the processed reinforcements through a spinning spinneret to form a primary membrane. The reinforcements are replaced by the primary after post-processing, and repeating the coating process.

The present invention relates to a gas separation membrane for separating a target gas species from a mixture of gas species, the membrane comprising: (i) a porous substrate having a first and second surface region between which the mixture of gas species will flow; (ii) a sealing polymer layer of different composition to the porous substrate that (a) forms a continuous coating across the second surface region of the substrate, and (b) is permeable to the mixture of gas species; and (iii) a selective polymer layer in the form of a cross linked macromolecular film that (a) is located on and covalently coupled to the sealing polymer layer, and (b) has a higher permeability to the target gas species relative to other gas species present in the mixture of gas species that is to be subjected to separation.

Membranes are provided for use in reverse osmosis applications. Such membranes include a nanofibrous scaffold in combination with a barrier layer. The barrier layer is formed of a polymeric matrix having functionalized cellulose nanofibers incorporated therein. The membranes may, in embodiments, also include a substrate.

A method for making a composite polyamide membrane including a porous support and a thin film polyamide layer, wherein the method includes: (i) applying a polar solution comprising a polyfunctional amine monomer and a non-polar solution comprising a polyfunctional acyl halide monomer to a surface of a porous support and interfacially polymerizing the monomers to form a thin film polyamide layer; (ii) treating the thin film polyamide layer with a polyfunctional arene compound; and (iii) exposing the thin film polyamide layer to nitrous acid; wherein the polar and non-polar solutions further comprises at least one of the following: (A) at least one of the solutions further comprises a tri-hydrocarbyl phosphate compound represented by Formula (I): and (B) the non-polar solution further comprises an acid-containing monomer comprising a C.sub.2-C.sub.20 hydrocarbon moiety substituted with at least one carboxylic acid functional group or salt thereof and at least one amine-reactive functional group. ##STR00001##