The objective of the present invention is to provide a porous support that is unlikely to curl (the incidence of MD curling is low). This porous support has a polymer porous layer on one surface of a nonwoven cloth layer, the nonwoven cloth layer having an MD bend stiffness of 1.2 to 2.1 g.Math.cm.sup.2/cm, and an MD bend recovery of 0.3 to 0.6 g.Math.cm/cm. The nonwoven cloth layer is impregnated with a polymer that is the material for forming the polymer porous layer, the impregnation ratio of the polymer impregnated in the nonwoven cloth layer being 25 to 34% by weight of the total weight of the polymer in the polymer porous layer and the polymer impregnated in the nonwoven cloth layer.

A method for manufacturing a hollow fiber membrane has a spinning step of applying a first membrane forming stock solution and a second membrane forming stock solution for forming a porous membrane layer to the outer peripheral surface of a hollow porous base material using a nozzle for hollow fiber membrane spinning and solidifying these membrane forming stock solutions, wherein a draft ratio (V.sub.B/V.sub.A), which is the ratio of feed velocity V.sub.B for hollow porous base material fed out from a base material feed opening to linear velocity V.sub.A for the first membrane forming stock solution and the second membrane forming stock solution discharged from a membrane forming stock solution discharge opening of the nozzle for hollow fiber membrane spinning, is set to 1-6.

The invention relates to methods for the synthesis of a thin-film composite membrane, comprising the following steps: a) providing an ultrafiltration porous support membrane, coated at the outer surface with a thin film, synthesized through interfacial polymerisation or interfacial initiation of polymerisation, b) contacting the membrane with a first solution comprising a first monomer, and allowing the solution to impregnate inside the thin film of the membrane, c) discarding the first solution comprising the first monomer, d) contacting the membrane with a second solution comprising a second monomer, and allowing the solution to impregnate inside the thin film of membrane, whereby the second monomer reacts with the first monomer and optionally with reactive groups of the thin film, e) discarding the second solution comprising the second monomer.

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.

A method for preparing a high-selectivity lithium-magnesium separation membrane includes: (1) preparing an aqueous phase mixture containing aqueous phase monomer, crown ethers or aza-macrocycles, acid acceptor, surfactant and water; (2) preparing an organic phase mixture containing organic phase monomer, and organic solvent that is incompatible with water; (3) contacting the supporting membrane with the aqueous phase mixture to obtain an aqueous phase monomer-adsorbed supporting membrane; (4) contacting the aqueous phase monomer-adsorbed supporting membrane with an organic phase mixture for an interfacial polymerization reaction; and (5) placing a nascent membrane obtained into a drying oven and heat-treating the membrane to obtain a lithium-magnesium separation membrane. The present method is simple in preparation process, mild in preparation conditions, easy to scale up, and easy to realize industrial production. The prepared high-selectivity lithium-magnesium separation membrane is large in permeation flux, high in lithium-magnesium selectivity and good in long-term operation stability.

The present disclosure relates to a water-treatment separation membrane including: a porous support and a polyamide layer formed on the porous support, wherein the polyamide layer contains an antioxidant having a solubility parameter value of 9 (J/cm.sup.3).sup.1/2 to 22 (J/cm.sup.3).sup.1/2, and a method of manufacturing the same.

The present invention provides a method for the preparation of thin film composite (TFC) membranes, preferably solvent resistant TFC membranes, by interracial polymerization (IFP), more in particular solvent resistant TFC membranes wherein a thin PA-layer is deposited on a porous support membrane. Said method comprises the replacement of the aqueous and/or the organic solvent in the IFP method by an ionic liquid (IL) as solvent for the monomers which form said TFC membranes, to alter the top layer morphology, thickness and crosslinking degree.

An object of the present invention is to provide a composite reverse osmosis membrane having improved water permeability and antifouling performance, and a method for producing the same. The composite reverse osmosis membrane of the present invention includes: a porous support; and a skin layer formed on a surface of the porous support. The skin layer contains a polyamide resin. The polyamide resin is a modified polyamide resin modified with an alkylenediamine derivative.

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.

Disclosed is the preparation of composite membranes formed by a tailored selective chemical modification of an ultra-thin nanoporous surface layer of a semi-crystalline mesoporous poly (aryl ether ketone) membrane with graded density pore structure. The composite separation layer is synthesized in situ on the poly (aryl ether ketone) substrate surface and is covalently linked to the surface of the semi-crystalline mesoporous poly (aryl ether ketone) membrane. Hollow fiber configuration is the preferred embodiment of forming the functionalized the poly (aryl ether ketone) membranes. Composite poly (aryl ether ketone) membranes of the present invention are particularly useful for a broad range of fluid separation applications, including organic solvent ultrafiltration and nanofiltration to separate and recover active pharmaceutical ingredients.