The present disclosure provides the synthesis of an imidazolium-based functional ionic liquid copolymer (PMMA-b-PIL-R*) and a preparation method of an alloy ultra-filtration membrane. Firstly, PMMA-b-PIL-R* is prepared from methyl methacrylate (MMA) and polymerizable imidazolium-based functional ionic liquid (IL-R*) containing double bonding as the reactive monomers through sequential radical polymerization. With the use of a non-solvent induced phase separation method, PMMA-b-PIL-R* is introduced into the body of a polymeric membrane material, so as to prepare an alloy ultra-filtration membrane. A hydrogen-bond interaction is generated between the carbonyl in the molecular chain of PMMA-b-PIL-R* and the H . . . C—Cl structure in the molecular chain of the polymeric membrane material, which enhances the compatibility between the molecular chains of PMMA-b-PIL-R* and the polymeric membrane material, so that it can be stable in the ultra-filtration membrane; the imidazole groups and functional groups in the molecular chain of PMMA-b-PIL-R* can provide a good hydrophilicity.

Described herein is a solution including at least one sulfone polymer, at least one water-soluble polymer, and gamma-valerolactone. Also described herein is a process of making a membrane using the solution, and a method of using the membrane for water ultrafiltration and/or dialysis.

Disclosed are compositions that may be useful for forming synthetic membranes, methods of forming membranes therefrom, and membranes. In an embodiment, a membrane comprises a free hydrophilic polymer comprising a polyoxazoline, and a polyurethane, the polyurethane comprising a backbone comprising the reaction product of a diisocyanate, a polymeric aliphatic 5 diol, and optionally a chain extender.

The present disclosure discloses an asymmetric electrolyte membrane, a membrane electrode assembly including the same, a water electrolysis apparatus including the same and a method for manufacturing the same. More particularly, it discloses an asymmetric electrolyte membrane having a porous layer and a dense layer at the same time, a membrane electrode assembly including the same, a water electrolysis apparatus including the same and a method for manufacturing the same.

An object of the present invention is to provide a hollow fiber membrane with enhanced phosphorus-removing performance without impairing antithrombogenicity in order to inhibit in vivo accumulation of phosphate ions in living body that might cause bone metabolism disorders. The present inventors have found that a hollow fiber membrane having a specific membrane structure and a specific membrane composition possesses a very useful range for inner surface charges of the membrane. More particularly, the inventors have discovered that the above object can be achieved in a limited range in which the zeta potential on the inner surface of a hollow fiber membrane measured under given certain conditions is greater than −3.0 mV but less than 0 mV. This finding has led to the completion of the present invention.

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 invention relates to a method for producing a polyelectrolyte complex (PEC) membrane having a predetermined porosity via salt dilution induced phase separation, in which a liquid polymer solution (P) containing polyanions (A) and polycations (C) dissolved in an aqueous medium at an overcritical salt concentration is exposed to an aqueous medium.

Hydrophobic flat membrane made from a vinylidene fluoride polymer with a wall, a first surface, and a second surface. The membrane has on its first surface a network structure with open pores and on its second surface a continuous skin in which pores are formed, and adjacent to the skin of the second surface a supporting layer with an isotropic pore structure across the wall thickness, wherein the supporting layer extends over at least 80% of the wall thickness and wherein the pores of the supporting layer have an average diameter of less than 1 μm. The weight average of the molecular weight M.sub.W of the vinylidene fluoride polymer lies in the range from 300 000 to 500 000 daltons, and the polydispersivity M.sub.W/M.sub.N is greater than 5.5.

The pores in the skin of the second surface have a closed perimeter in the plane of the skin and an average ratio of the extension in the direction of the longest axis thereof to the extension in the direction of the shortest axis thereof of at most 5. The pores in the first surface and second surface have an essentially isotropic distribution of their orientation. The porosity of the membrane lies in the range from 50 to 90 vol. % and the wall thickness in the range from 50 to 300 μm. The membrane has a maximum separating pore diameter d.sub.max in the range from 0.05 to 1.5 μm.

The present invention discloses a polyvinylidene fluoride hollow fiber membrane and a preparation method thereof. The hollow fiber membrane comprises 30%-50% of polyvinylidene fluoride resin, 40%-60% of inorganic molecular solution in-situ pore-forming agent and 5%-20% of organic diluent. The preparation method comprises preparing the inorganic molecular solution in-situ pore-forming agent formed from organic sol, mixing the inorganic molecular solution in-situ pore-forming agent formed from the organic sol with high-molecular polymer resin and the organic diluent to obtain a material A,extruding hollow fibers through a forming mold, stretching on line by 2-3 times to obtain hollow fiber filaments, extracting the hollow fiber filaments with an organic solvent to remove all organic matters, removing inorganic matters dispersed in the hollow fiber filaments by using an acid or alkaline solution to form a porous membrane and cleaning the porous membrane, setting and performing heat treatment to obtain the polyvinylidene fluoride hollow fiber membrane.

The present invention relates to a porous membrane including a polymer including a polyvinylidene fluoride-based resin as a main component, and a branched polyvinylidene fluoride-based resin as the polyvinylidene fluoride-based resin, in which the polymer has a value of a of 0.32 to 0.41 and a value of b of 0.18 to 0.42, each of which is determined by approximation according to the formula 1 below from a radius of gyration <S.sup.2>.sup.1/2 and an absolute molecular weight M.sub.w of the polymer which are measured by GPC-MALS (gel permeation chromatograph equipped with a multi-angle light scattering detector). <S.sup.2>.sup.1/2=bM.sub.w.sup.a (Formula 1)