A method for making a composite polyamide membrane including a porous support and a thin film polyamide layer including the steps of applying a polyfunctional amine monomer and a combination amine-reactive compounds to a surface of the porous support and reacting the constituents to form a thin film polyamide layer, wherein the amine-reactive compounds include: i) a polyfunctional amine-reactive monomer including two to three amine-reactive moieties selected from acyl halide, sulfonyl halide and anhydride, ii) a polyfunctional amine-reactive monomer including at least four amine-reactive moieties selected from acyl halide, sulfonyl halide and anhydride, and iii) an acid compound including at least on carboxylic acid moiety or salt thereof and at least one amine-reactive moiety selected from acyl halide and sulfonyl halide.

Provided herein are ion-selective separation membranes including a polymer matrix and a metal compound dispersed within the polymer matrix. The metal compound includes H.sub.aLi.sub.bX.sub.cO.sub.a, where a is from 1 to 1.5, b is from 0 to 0.1, c is from 1 to 2, d is from 4 to 4.5, and X includes manganese or titanium.

The purpose of the present invention is to provide a polyamide porous membrane that makes it possible to improve liquid permeability while suppressing deterioration of membrane separation performance. A polyamide porous membrane according to the present invention is formed from a polyamide resin, wherein in structural analysis by X-ray diffraction, the ratio of crystals with respect to the total amount of a crystals and crystals is not less than 38%.

The present invention relates to the field of composite membranes. More specifically, the present invention relates to a composite filter membrane comprising: a filtration layer, a support layer comprising at least one through-hole; and an intermediate layer sandwiched between said filtration layer and said support layer.

A composite polyamide reverse osmosis membrane comprising a polyamide layer; where the polyamide layer has a thickness in the range of 50-250 nm, and large open spaces (i.e., free volumes); where the open spaces are defined by a ratio of water flux, J.sub.w, (gfd) divided by the average surface roughness, Ra, (nm) of the polyamide layer; wherein the composite polyamide reverse osmosis membrane has the ratio of J.sub.w/Ra>0.35 gfd/nm when tested at 65 psi, using an aqueous solution containing 250 ppm of NaCl; and a microporous support with a thickness ranging from 100-150 m. The present invention also relates to processes of fabricating the composite polyamide reverse osmosis membrane.

The present invention refers to a process for obtaining reduced graphene oxide (rGO) porous membranes, homogeneous, without cracks, using very low quantities of graphene oxide (GO) nanosheets, highly adhered to the porous support and with high mechanical stability. The obtained rGO membranes present high quality and excellent operational efficiency and can be used in applications involving separation of ionic, molecular and biological species in liquid and gaseous phases, such as the treatment of water and industrial effluents and/or gas purification. Furthermore, the present invention also describes an ideal reactor to make it possible to obtain said reduced graphene oxide membranes obtained by the process described herein.

A method for separating bisphenol A (BPA) from an aqueous solution includes contacting an aqueous solution containing BPA with a polyimide polymer on a porous support; and passing at least a portion of the aqueous solution through the polyimide polymer to form a purified water permeate and a BPA residue retentate. The BPA residue retentate is present as a layer on an outside surface of the polyimide polymer. The polyimide polymer contains reacted units of a fluorinated phthalic monomer and one or more amino carboxyl aryl monomers.

The present disclosure describes a process of obtaining a carbon membrane derived from polymer polybenzoxazine, for improved separation of gases with different kinetic diameters such as helium (2.60 ), hydrogen (2.89 ), carbon dioxide (3,30 ), oxygen (3.46 ), nitrogen (3.64 ), carbon monoxide (3.70 ), methane (3.80 ), ethylene (4.23 ) and ethane (4.42 ) from the molecular sieving mechanism.

The present disclosure provides a high-temperature-resistant deep penetration molecular membrane acid copolymer and a preparation method thereof. The copolymer is formed by polymerizing four raw monomers including 2-acrylamido-2-methylpropanesulphonic acid, vinyl phosphonic acid, alkyl dimethylallyl ammonium chloride, and perfluoropolyether acrylate. The method comprises: S1: mixing and stirring solvent oil, an emulsifier, the alkyl dimethyl allyl ammonium chloride, and the perfluoropolyether acrylate to be dispersed homogeneously to obtain an oil phase; S2: mixing and stirring the 2-acrylamido-2-methylpropanesulphonic acid, the vinyl phosphonic acid, a complexing agent, and distilled water, and adjusting pH to obtain an aqueous phase; S3: slowly dropwise adding the aqueous phase to the oil phase; and S4: introducing nitrogen into the water-in-oil emulsion to remove oxygen, then adding an initiator and carrying out a heating polymerization reaction to obtain copolymer emulsion (i.e., a molecular membrane agent). The copolymer emulsion is added to an acid solution to obtain molecular membrane acid.

The present invention relates to a method for producing a porous membrane, the method being characterized in that a solvent system comprising 2-pyrrolidone and N-alkyl-2-pyrrolidone is used, wherein the content ratio of 2-pyrrolidone to N-alkyl-2-pyrrolidone in the solvent system is from 90%:10% to 10%:90%, based on mass %, and wherein N-alkyl-2-pyrrolidone is N-propyl-2-pyrrolidone and/or N-butyl-2-pyrrolidone. Furthermore, the present invention relates to a porous membrane obtainable by said method. Moreover, the present invention relates to the use of a specific solvent system for the production of a porous membrane.