A composite membrane comprising a supporting membrane that includes polyphenylene oxide and a separation layer that is disposed on one main surface of the supporting membrane, wherein the poiyphenylene oxide is sulfonated on the one main surface of the supporting membrane and the separation layer includes polyvinyl alcohol having an ionic functional group.

A reverse osmosis membrane is disclosed that has a hydrogel disposed on its surface, wherein the hydrogel is formed from a crosslinked polyvinylpyrrolidone or a copolymer of vinyl pyrrolidone. The hydrogel-coated membrane resists fouling by feed water contaminants. The permeate flux rate and salt rejection of the underlying membrane are not negatively affected by the hydrogel coating.

Described herein is a crosslinked graphene based composite membrane that provides selective resistance to fluids solutes while providing water permeability, such as a selectively permeable membrane comprising a crosslinked graphene with a polyvinyl alcohol and silica-nanoparticle layer that can provide enhanced water separation. Also described herein are methods for making such membranes and methods of using the membranes for dehydrating or removing solutes from water.

The present invention provides a method for manufacturing a porous membrane having high water permeability and hydrophilicity, which is not easily affected by a treatment such as washing, the method including: preparing, as a substrate, a membrane having a plurality of pores, which includes a water-insoluble resin such as polysulfone and a water-soluble resin including a monomer unit of polyvinylpyrrolidone or a monomer unit of polyvinyl alcohol; and irradiating the substrate with an electron beam in the presence of an aqueous solvent to crosslink at least a part of the water-soluble resin.

One aspect of the present invention is a composite hollow fiber membrane including: a semipermeable membrane layer; and a supporting layer that has a hollow fiber shape and is porous, wherein the semipermeable membrane layer contains a crosslinked polyamide polymer composed of a polyfunctional amine compound and a polyfunctional acid halide compound, the supporting layer has a gradient structure in which pores of the supporting layer gradually increase in size from one of an inner surface and an outer surface to the other, has a cut-off particle size of 0.001 to 0.3 μm, and contains a crosslinked hydrophilic resin on at least a dense surface having smaller pores of the inner surface and the outer surface, and the semipermeable membrane layer is in contact with the dense surface of the supporting layer.

Membranes, methods of making the membranes, and methods of using the membranes are described herein. The membranes can comprise a support layer, and a selective polymer layer disposed on the support layer. The selective polymer layer can comprise an oxidatively stable carrier and a borate additive dispersed within a hydrophilic polymer matrix. The oxidatively stable carrier can comprise a quaternaryammonium hydroxide carrier (e.g., a mobile carrier such as a small molecule quaternaryammonium hydroxide, or a fixed carrier such as a quaternaryammonium hydroxide-containing polymer), a quaternaryammonium fluoride carrier (e.g., a mobile carrier such as a small molecule quaternaryammonium fluoride, or a fixed carrier such as a quaternaryammonium fluoride-containing polymer), or a combination thereof. The borate additive can comprise a borate salt, a boric acid, or a combination thereof. The membranes can exhibit selective permeability to gases. As such, the membranes can be for the selective removal of carbon dioxide and/or hydrogen sulfide from hydrogen and/or nitrogen.

A bipolar membrane comprising a cation exchange mat of one or more cation exchange polymers, an anion exchange mat of one or more anion exchange polymers, and an internal 3D bipolar interface, disposed between the cation and anion exchange layers, including a mixture of at least one cation exchange polymer and at least one anion exchange polymer, such that an interface of the at least one cation exchange polymer and the at least one anion exchange polymer is the internal 3D bipolar interface that has a large area, and the at least one cation exchange polymer in the 3D bipolar interface is connected to the one or more cation exchange polymers of the cation exchange layer, and the at least one anion exchange polymer in the 3D bipolar interface is connected to the one or more anion exchange polymers of the anion exchange layer.

The present invention relates to polymeric membranes. In particular, the present invention relates to the use of membranes comprising polyvinyl alcohol in electrophoresis.

A reverse osmosis membrane is disclosed that has a hydrogel disposed on its surface, wherein the hydrogel is formed from a crosslinked polyvinylpyrrolidone or a copolymer of vinyl pyrrolidone. The hydrogel-coated membrane resists fouling by feed water contaminants. The permeate flux rate and salt rejection of the underlying membrane are not negatively affected by the hydrogel coating.

A method for synthesizing a nanocomposite membrane, and a synthesized nanocomposite membrane made thereby. The method may include steps of preparing Fe.sub.3O.sub.4-tolylene di-isocyanate (TDI) nanoparticles by reacting Fe.sub.3O.sub.4 nanoparticles and TDI powder, preparing Fe.sub.3O.sub.4-TDI-TiO.sub.2 nanoparticles, sulfonating the Fe.sub.3O.sub.4-TDI-TiO.sub.2 nanoparticles, preparing a first polymer solution, dispersing the Fe.sub.3O.sub.4-TDI-TiO.sub.2SO.sub.3H nanoparticles into the first polymer solution to obtain a second homogenous solution, and casting and drying the second homogenous solution to obtain the nanocomposite membrane.