The present invention relates to a radiation-resistant microporous membrane having a hydrophobicity gradient, to a method for the preparation thereof, and to the use of the membrane in the sterilizing filtration of gaseous fluids or as a liquid barrier in liquid-containing systems to be vented.

Disclosed are copolymers, comprising a plurality of zwitterionic repeat units, and a plurality of hydrophobic repeat units, wherein the hydrophobic repeat units each independently comprises a cross-linkable moiety; the cross-linked copolymer network, comprising such copolymer; as well as thin film composite membrane comprising such cross-linked copolymer network.

Membranes, methods of making the membranes, and methods of using the membranes are described herein. The membrane can include a support layer, and a selective polymer layer disposed on the support layer. The selective polymer layer can include a selective polymer matrix (e.g., hydrophilic polymer, a cross-linking agent, an amino compound, a CO.sub.2-philic ether, or a combination thereof), and optionally graphene oxide dispersed within the selective polymer matrix. The membranes can be used to separate carbon dioxide from hydrogen. Also provided are methods of purifying syngas using the membranes described herein.

Provided herein are gas permeable membranes comprising an amine-containing selective layer on top of a gas permeable polymer support as well as methods of making and using thereof. The membranes are useful for the separation of CO.sub.2 from N.sub.2-containing gases.

Provided are processes of removing particulate fouling from a filtration membrane or for preventing membrane fouling by particulate matter. A process capitalizes on reversal of a naturally occurring diisophoretic particle deposition to actively move particulate material away from a membrane. A process includes placing a microparticle including a salt in proximity to a membrane such that the microparticle creates a gradient generated spontaneous electric field or a gradient generated spontaneous chemiphoretic field in the solvent proximal to the membrane that actively draws charged particles away from the membrane thereby removing charged particulate matter away from the membrane or preventing its deposition.

A crosslinked copolymer is provided, which includes a copolymer crosslinked by a crosslinking agent. The copolymer is copolymerized of (a) styrene-based monomer, (b) monomer having conjugated double bonds or acrylate ester monomer, and (c) ammonium-containing heterocyclic monomer. The crosslinking agent is (d) ##STR00001##
or the product of the reaction between ##STR00002##
and (e) ##STR00003##
or a combination thereof. Z is ##STR00004##
wherein each R.sup.1 is independently H or C.sub.1-4 alkyl group, each R.sup.2 is independently H or C.sub.1-4 alkyl group, R.sup.3 is single bond, —O—, —S—, —CH.sub.2—, or —NH—. n is a positive integer. x is 1 to 12, y is 1 to 5, and z is 1 to 5.

Membranes comprising graphene oxide sheets and associated filter media and methods are provided. In some embodiments, a membrane may comprise graphene oxide sheets that have undergone one or more chemical treatments. The chemical treatment(s) may impart beneficial properties to the membrane, such as a relatively small d-spacing, compatibility with a broad range of environments, physical stability, and charge neutrality. For example, the graphene oxide sheets may undergo one or more chemical treatments that form chemical linkages between at least a portion of the graphene oxide sheets in the membrane. Such chemical linkages may impart a small d-spacing, broad compatibility, and/or allow relatively thick membranes to be formed. In certain embodiments, the graphene oxide sheets may undergo one or more chemical treatment that imparts relative charge neutrality to the membrane by altering the ionizability of certain functional groups. Graphene oxide membranes, described herein, can be used for a wide range applications.

A gas separation membrane, a method for making the gas separation membrane, and a method for using the gas separation membrane are provided. An exemplary gas separation membrane includes a polyether-block-polyamide (PEBA) matrix and a cross-linked network including functionalized polyhedral oligomeric silsesquioxane (POSS) nanoparticles dispersed through the PEBA matrix.

A steam permselective membrane containing a crosslinked hydrophilic polymer is provided. The steam permselective membrane may further contain at least one alkali metal compound selected from the group consisting of a cesium compound, a potassium compound and a rubidium compound.

The present disclosure discloses a method of fabrication of free standing open pore membranes with uniform pore size and shape and ordered pore distribution, and its use for synthesis of nanoparticle patterns. The method includes applying a photoresist layer to the top surface of a substrate, heating the photoresist layer for a period of time, and exposing the photoresist layer to a dose of ultraviolet radiation through a mask having a predetermined pattern. The dose of ultraviolet radiation is controlled in intensity and time and the photoresist layer is exposed such that a top portion of the photoresist layer through which the dose of ultraviolet radiation enters the photoresist layer undergoes greater cross linking than a bottom portion of the photoresist layer immediately adjacent to the top surface of the substrate such that a cross linking gradient develops through a thickness of the photoresist layer. The mask is removed and the membrane is readily detached from the top surface of the substrate since the portion of the membrane adjacent to the top surface is less cross linked than the top surface of the membrane. The detached membrane forms a free standing patterned membrane having a preselected pattern of open pores. The method can be used with positive photoresist materials as well when deposited on a UV transparent substrate so that the photoresist can be exposed to UV from its top with photomask and UV exposure from its back of the transparent substrate without the photomask.