A membrane for separating organic solvents such as methanol and toluene is provided. A plurality methacrylate polymer brushes, e.g., composed of hydroxyethyl methacrylate (HEMA) monomers or aminoethyl methacrylate (AEMA) monomers, are grafted from a crosslinked polyimide support using Single Electron Transfer-Living Radical Polymerization (SET-LRP). The polymer brushes themselves are also crosslinked by ethylene glycol dimethacrylate (EGDMA), triethylene glycol dimethacryalte (TEGDMA) trimesic acid, and/or itaconic acid. These hydrophilic polymeric brush membranes demonstrate pore stiffening and yet also opening, obtaining high selectivity at reasonable permeability and reduced energy requirements for commercially relevant separations, e.g., methanol/toluene. The addition of the crosslinker prevents loss of selectivity as a result of imparting increased rigidity, enabling the membranes to be operated at higher operating pressures for increased throughput. These membranes would be beneficial for use in pharmaceutical, chemical, petroleum, food, and biotechnology industries, e.g., in the manufacture of polymethacrylic acid, the manufacture of paraxylene, etc.

The invention concerns the field of polymer chemistry and relates to membranes, such as those used as membranes for the preparation of aqueous solutions by means of reverse osmosis or microfiltration, ultrafiltration or nanofiltration, for example.

The object of the present invention is the specification of membranes that exhibit a reduced fouling tendency with equally suitable or improved filtration properties, as well as the specification of a simple and cost-effective method for the production thereof.

The object is attained with membranes comprising a substrate on which a porous supporting layer is arranged, on which supporting layer a separation-active layer is arranged, and on which separation-active layer a cover layer is also arranged, wherein the material of the separation-active layer comprises functional groups which primarily have carbon-carbon triple bonds and/or carbon-nitrogen triple bonds, and wherein the material of the cover layer has functional groups which are primarily at least azide groups, and the functional groups having at least carbon-carbon triple bonds and/or carbon-nitrogen triple bonds are chemically coupled covalently with the azide groups.

A virus removal membrane is formed from a hydrophilized synthetic polymer, in which, when a solution containing gold colloids having a diameter of 20 nm is applied through a primary surface to the virus removal membrane to allow the virus removal membrane to capture the gold colloids for measurement of brightness in a cross section of the virus removal membrane, a value obtained by dividing a standard deviation of a value of an area of a spectrum of variation in the brightness by an average of the value of the area is 0.01 or more and 1.5 or less; and a thickness of a portion, where gold colloids having a diameter of 20 nm or more and 30 nm or less are captured, in the cross section of the virus removal membrane in a wet state is 10 m or more and 30 m or less.

Methods for hydrophilizing porous PTFE membranes, and hydrophilized membranes, are disclosed.

A membrane assembly is provided. The membrane assembly comprises a membrane having a first surface and an opposing second surface, and a layer of anti-fouling polymer selected from the group consisting of an optionally functionalized hyperbranched polyglycerol, a hyperbranched polyimine, a zwitterionic copolymer obtainable by polymerizing 2-methacryloyloxyethyl lipoate with at least one of [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl) ammonium hydroxide or 2-methacryloyloxyethylphosphorylcholine, and combinations thereof arranged on the first surface of the membrane. A method of manufacturing a membrane assembly is also provided.

A membrane including a support and an active layer. The active layer includes reacted units of a polyamine compound, a polyfunctional acid halide compound, and nickel oxide (NiO) nanoparticles (NPs). A surface of the NiO NPs is functionalized with an amino silane compound. The polyamine compound, the polyfunctional acid halide compound, and the amino silane compound are interfacially polymerized on the support to form the membrane.

The present disclosure relates to a scaling-resistant and yellowing-resistant composite reverse osmosis membrane and a preparation method thereof. By modifying the stability and yellowing of a coating of the reverse osmosis membrane, and grafting 2-(methacryloyloxy)ethyl)dimethyl-3-sulphoproyl) ammonium hydroxide (MEDSAH) and ethylene glycol methacrylate (EGMA) as amphoteric monomers and N-(isobutoxymethyl)acrylamide (IBMA) as yellowing-resistant particles on a surface of the reverse osmosis membrane using active polymerization, the present disclosure forms a three-network high-performance PMEDSAH/PEGMA/PIBMA composite coating. By active regulation of a polyamide (PA) layer through the three systems, the reverse osmosis membrane has high compatibility due to PMEDSAH, and stability, high hydrophilicity and anti-protein fouling property due to PEGMA, as well as yellowing-resistant property by coating PIBMA on the surface. The test results show that the reverse osmosis membrane prepared by the present disclosure has excellent stability and yellowing-resistant property. And the flux and salt rejection are also higher than those of the existing reverse osmosis membranes.

A problem to be solved by the present invention is to provide an ion exchange membrane that can increase the surface area of a membrane effective for ion permeation, properly decreases the electric resistance of a flow passage between membranes and the attachment of a contaminating substance thereto, also enhances the mechanical strength of the membrane itself, and further, is less deformed or damaged due to swelling over a wide range of salt concentrations and even if there is a large difference in salt concentration between two solutions contacted with the membrane. The present invention provides an ion exchange membrane having a concavo-convex shape, wherein the ion exchange membrane has a flat portion in the vicinity of ends, and a convex curve and a concave curve resulting from curvatures of the ion exchange membrane itself form a convex part and a concave parts, respectively, in the concavo-convex shape of the ion exchange membrane, wherein the convex part extends linearly or curvedly, the concave part between the convex parts is flat, the concave part includes a first concave part adjacent to the convex part in the lateral direction of the convex part, along the longitudinal direction of the convex part, the convex part has an apex and a side face in the longitudinal direction, and the side face is inclined from the apex toward the first concave part.

Adsorptive membranes with sponge-like structures for direct recovery of lithium from geothermal brines and recycling of water from geothermal evaporation ponds are disclosed. The membrane surfaces are functionalized with task-specific chemicals capable of selective separation of lithium through host-guest complexation mechanism. The sponge-like structure provides high surface area resulting in an enhanced lithium adsorption capacity. The technology disclosed here aims to reduce the time required for lithium enrichment by evaporative concentration of geothermal brines and address the water loss problem thereof through enhanced solar-driven recycling of water.

A method for preparing a durably hydrophilic and uniform-pore ultrafiltration membrane is disclosed herein. Chemical reactions between the functional groups and the active bonds of the molecular chains in the membrane materials are initiated perform the grafting of hydrophilic chains on the polymer chains under conventional dissolution conditions of the polymer membrane material (dissolution with synchronized hydrophilization), so as to realize durable hydrophilization of the membrane materials. The resulting hydrophilized polymer solution (a nascent-state membrane) is introduced into a coagulation bath to initiate a crosslinking reaction among the hydrophilic chains. The resulting crosslinking serves to synergistically regulate subsequent phase separation and membrane formation (phase separation under synergistic crosslinking).