This invention provides a polymeric separation membrane that has excellent durable antibacterial effect and stain resistance, and a preparation method thereof. The polymeric separation membrane can be widely applied for water treatment, which belongs to the field of water treatment and membrane separation science and technology. The polymeric separation membrane containing quaternary ammonium salt is prepared by the immersion precipitation phase inversion method, using quaternary ammonium salt mixed with polymer and additives. This modification method effectively improves the antibacterial and antifouling ability of the polymeric separation membrane prolongs the service life of membranes and significantly inhibits the reproduction of bacterial and microbial. The preparation method has the advantages of simple process, easy operation, easy for promotion, and also avoids expensive equipment. The polymeric separation membrane has great antibacterial ability and stain resistance, therefore, it has potential application in the field of water treatment.

The invention relates to a method for creating a porous film through aqueous phase separation, the method comprising: i) providing an aqueous solution comprising a responsive copolymer, and optionally a charged polymer, wherein at least one of the monomers in the responsive copolymer is a responsive monomer; ii) forming the aqueous solution into a thin layer and contacting the thin layer of aqueous solution with an aqueous coagulation solution in which the responsive copolymer is not soluble, or contacting the thin layer of aqueous solution with an aqueous coagulation solution in which a complex comprising the responsive copolymer and the charged polymer is not soluble; and iii) allowing solvent exchange between the aqueous solution and the aqueous coagulation solution to produce a porous film. The invention further relates to porous films or membranes thus obtained.

An object is to realize a novel reverse osmosis membrane (more specifically, reverse osmosis composite membrane) that is capable of suppressing biofouling. The object is attained with use of a reverse osmosis composite membrane which is obtained by chemically modifying a surface thereof with a compound that has an amino group and that is obtained by modifying the amino group with two molecules of -picolyl group and has a dipicolylamine structure.

A method for coating hollow fiber membranes is disclosed. The method includes preparing a continuous circulating circuit, which includes a membrane contactor module, two liquid reservoirs containing a solvent, two pipeline paths, and at least one injector. The membrane module include a plurality of hollow fiber membranes with an inside area and an outside area, and a housing, where the plurality of hollow fiber membranes are extended inside the housing. The method further include forming a plurality of wetted hollow fiber membranes with the solvent by circulating the solvent through the continuous circulating circuit, filling at least one of the two liquid reservoirs with a coating solution, forming a coating layer on a surface of at least one of the inside area or the outside area of the plurality of wetted hollow fiber membranes by circulating the coating solution through the continuous circulating circuit, and forming a uniform coating layer by injecting the coating solution by the injector for intrusion of the coating solution through the coating layer.

A hollow fiber membrane fluid transport device is disclosed wherein the fibers are comprised of Polytetrafluoroethylene (PTFE), and the potting materials are comprised of fluorocopolymer and or fluoroterpolymer based materials. The potting of the device utilizes a compressed chemically resistant fluorocopolymer and or fluoroterpolymer film, allows for ease of manufacture without destruction of the PTFE hollow fibers, with high packing densities, and without the processing complexity of pre-melting, extruding, or chemical crosslinking of any polymeric adhesives. Furthermore, the PTFE hollow fibers can be treated with a fluoropolymeric solvent solution before the chemically resistant film is applied to enhance the adhesion of the PTFE fiber to the film. PTFE hollow fibers, and its respective fluoro-co and terpolymers as potting films impart high packing densities, superb chemical resistance and temperature resistance without membrane contamination, or low fiber pull strength, as is sometimes observed with standard potting materials such as polyurethane and epoxy.

A hollow fiber membrane fluid transport device is disclosed wherein the fibers are comprised of Polytetrafluoroethylene (PTFE), and the potting materials are comprised of fluorocopolymer and or fluoroterpolymer based materials. The potting of the device utilizes a compressed chemically resistant fluorocopolymer and or fluoroterpolymer film, allows for ease of manufacture without destruction of the PTFE hollow fibers, with high packing densities, and without the processing complexity of pre-melting, extruding, or chemical crosslinking of any polymeric adhesives. Furthermore, the PTFE hollow fibers can be treated with a fluoropolymeric solvent solution before the chemically resistant film is applied to enhance the adhesion of the PTFE fiber to the film. PTFE hollow fibers, and its respective fluoro-co and terpolymers as potting films impart high packing densities, superb chemical resistance and temperature resistance without membrane contamination, or low fiber pull strength, as is sometimes observed with standard potting materials such as polyurethane and epoxy.

An ultrafiltration membrane comprising: (i) a first polymer, and (ii) a second, charged polymer wherein the first polymer and second polymer have different hydrophobicities.

This invention provides a polymeric separation membrane that has excellent durable antibacterial effect and stain resistance, and a preparation method thereof. The polymeric separation membrane can be widely applied for water treatment, which belongs to the field of water treatment and membrane separation science and technology. The polymeric separation membrane containing quaternary ammonium salt is prepared by the immersion precipitation phase inversion method, using quaternary ammonium salt mixed with polymer and additives. This modification method effectively improves the antibacterial and antifouling ability of the polymeric separation membrane prolongs the service life of membranes and significantly inhibits the reproduction of bacterial and microbial. The preparation method has the advantages of simple process, easy operation, easy for promotion, and also avoids expensive equipment. The polymeric separation membrane has great antibacterial ability and stain resistance, therefore, it has potential application in the field of water treatment.

A porous asymmetric membrane comprises a hydrophobic polymer comprising a poly(phenylene ether) or poly(phenylene ether) copolymer; and a polymer additive. A separation module can be fabricated from the porous asymmetric membrane. A method of forming the porous asymmetric membrane comprises: dissolving a hydrophobic polymer comprising a poly(phenylene ether) or poly(phenylene ether) copolymer and, a polymer additive in a water-miscible polar aprotic solvent to form a porous asymmetric membrane-forming composition; and phase-inverting the porous asymmetric membrane forming-composition in a first non-solvent composition to form the porous asymmetric membrane. The polymer additive comprises hydrophilic functional groups, copolymerized hydrophilic monomers, or blocks of hydrophilic monomer repeat units. For example, the polymer additive can comprise a hydrophilic polymer or amphiphilic polymer. The porous asymmetric membrane can be a flat membrane or hollow fiber.

Provided is a hydrophilic porous membrane including a porous membrane and a hydroxyalkyl cellulose (preferably, hydroxypropyl cellulose) retained in the porous membrane, the hydroxyalkyl cellulose having a weight-average molecular weight of 10,000 or more and less than 110,000. The hydrophilic porous membrane of embodiments of the invention has high water permeability and can pass an integrity test in the case of being used as a filtration membrane of a filter cartridge. Also provided is a method for producing the above-mentioned hydrophilic porous membrane, the method comprising causing a hydrophilizing liquid including 0.005% to 0.500% by mass of a hydroxyalkyl cellulose having a weight-average molecular weight of 10,000 or more and less than 110,000, to permeate a porous membrane.