A perfluoropolymer hollow fiber composite membrane preparation method includes the steps of (A) preparing a supporting layer of the perfluoropolymer hollow fiber composite membrane, (B) preparing a membrane casting solution, which includes obtaining a mixed solution by mixing a perfluoropolymer water dispersion emulsion, a spinning carrier and solvent, and defoaming the mixed solution at vacuum and a constant temperature, (C) preparing a nascent hollow fiber composite membrane, which includes compositing by uniformly coating the membrane casting solution on an outer surface of the supporting layer through an annular spinneret using chemical fiber concentric circle composite spinning technology, putting the supporting layer after compositing into a coagulant, solidifying and forming, and (D) drying after putting the nascent hollow fiber composite membrane to a hot air box, cleaning, sintering, and performing heat preservation. The prepared membrane has a thin wall, thermal and chemical resistance and good mechanical performance.

A membrane sorbent is described, which comprises 1-6 wt % silicon carbide nanoparticles dispersed in a polymer matrix. The polymer matrix may comprise polysulfone and polyvinylpyrrolidone. The membrane sorbent is used for separating oil from a contaminated water mixture. The silicon carbide nanoparticles of the membrane sorbent may be made from rice husk ash.

The present disclosure relates to a microporous hollow fiber filter membrane having a large inner diameter and a thin wall. The fiber can be used for sterile filtration of liquids or removal of particles from liquids. The disclosure further relates to a method for producing the membrane and a filter device comprising the membrane.

A porous membrane comprising a membrane-forming polymer (A) and a polymer (B) containing a methyl methacrylate unit and a hydroxyl group-containing (meth)acrylate (b1) unit. A flux of pure water to permeate the porous membrane is preferably 10 (m.sup.3/m.sup.2/MPa/h) or more and less than 200 (m.sup.3/m.sup.2/MPa/h). The contact angle of the bulk of the membrane-forming polymer (A) is preferably 60° or more. The membrane-forming polymer (A) is preferably a fluorine-containing polymer. The polymer (B) is preferably a random copolymer.

The invention is related to a super-hydrophilic/underwater super-oleophobic attapulgite separation membrane, and a preparation method and use thereof. Monodispersed hydrophilic nanoparticulates are loaded on a surface of nanoparticles, to obtain a super-hydrophilic nanocomposite material with a micro-nanostructure. The nanocomposite material is dispersed in a mixed aqueous solution of polyacrylamide and methyl cellulose, to obtain a membrane-forming slurry after vigorous stirring. A disc-shaped porous support is infiltrated with water and placed on a horizontal surface, and then a certain volume of the membrane-forming slurry is slowly and uniformly drip-coated on a surface of the support, dried and sintered to obtain a super-hydrophilic/underwater super-oleophobic microfiltration membrane layer.

The present invention deals with a method for obtaining membranes in the form of hollow fibers with application in the field of carbon dioxide removal from natural gas. The aforementioned membranes are obtained by means of heat treatment of polymeric membranes. In this method, polymeric membranes are obtained by a phase-inversion technique by immersion-precipitation and are subsequently subjected to a heat treatment, that is, that the membranes effectively become precursor membranes of the heat treatment. The heat treatment process involves the optimization of the heating rate, temperature, and stabilization time variables, aiming at the improvement of the transport properties of the polymeric membranes. After the heat treatment, it becomes possible to use the membranes in separation processes of gases which operate at pressures greater than 30 bar, with selectivity for carbon dioxide (CO.sub.2).

The invention is related to a super-hydrophilic/underwater super-oleophobic attapulgite separation membrane, and a preparation method and use thereof. Monodispersed hydrophilic nanoparticulates are loaded on a surface of nanoparticles, to obtain a super-hydrophilic nanocomposite material with a micro-nanostructure. The nanocomposite material is dispersed in a mixed aqueous solution of polyacrylamide and methyl cellulose, to obtain a membrane-forming slurry after vigorous stirring. A disc-shaped porous support is infiltrated with water and placed on a horizontal surface, and then a certain volume of the membrane-forming slurry is slowly and uniformly drip-coated on a surface of the support, dried and sintered to obtain a super-hydrophilic/underwater super-oleophobic microfiltration membrane layer.

The present invention relates to a method for the production of a positively charged membrane. Furthermore the present invention relates to a positively charged membrane obtainable by the methods of present invention and the use of these positively charged membranes.

Process for making membranes M comprising the following steps: a) providing a dope solution D comprising at least one polymer P and at least one solvent S, b) adding at least one coagulant C to said dope solution D to coagulate said at least one polymer P from said dope solution D to obtain a membrane M, wherein said at least one solvent S comprises more than 50% by weight of at least one compound according to formula (I) (I), wherein R.sup.1 and R.sup.2 are independently C.sub.1 to C.sub.20 alkyl, R.sup.3 is selected from H or an aliphatic rest, 20 R.sup.4 is selected from H or an aliphatic rest, AO represents at least one alkylene oxide, n is a number from 0 to 100. ##STR00001##

A polysulfone-urethane copolymer is disclosed, which can be used as a membrane polymer, e.g., a matrix polymer, a pore forming agent, or both, while enhancing a membrane's blood compatibility. Methods are disclosed for forming the copolymer and incorporating the copolymer in membranes (e.g., spun hollow fibers, flat membranes) and other products.