An asymmetric polyvinylidene chloride copolymer membrane is made by a method using a dope solution comprised of a polyvinylidene chloride copolymer and a solvent that solubilizes the polyvinylidene chloride copolymer that is shaped to form an initial shaped membrane. The initial shaped membrane is then quenched in a liquid comprised of a solvent that is miscible with the solvent that solubilizes the polyvinylidene chloride copolymer but is immiscible with the polyvinylidene chloride copolymer to form a wet asymmetric polyvinylidene chloride copolymer membrane. The solvents are removed from the wet membrane to form the asymmetric polyvinylidene chloride (PVDC) copolymer membrane. The membrane then may be further heated to form a carbon asymmetric membrane in which the porous support structure and separation layer of the PVDC membrane is maintained. The asymmetric carbon membrane may be useful to separate gases such as olefins from their corresponding paraffins, hydrogen from syngas or cracked gas, natural gas or refinery gas, oxygen/nitrogen, or carbon dioxide and methane.

A porous membrane includes a modacrylic copolymer. The modacrylic copolymer includes, with respect to 100 parts by mass of all structural units constituting the modacrylic copolymer, 15 to 85 parts by mass of a structural unit derived from acrylonitrile, 15 to 85 parts by mass of a structural unit derived from at least one halogen-containing monomer selected from the group consisting of vinyl halide and vinylidene halide, and 0 to 10 parts by mass of a structural unit derived from a vinyl monomer having an ionic substituent. The porous membrane can be produced by preparing a modacrylic copolymer solution by dissolving the modacrylic copolymer in a solvent, and bringing the modacrylic copolymer solution into contact with a non-solvent for the modacrylic copolymer such that the modacrylic copolymer solution is solidified.

Membranes having an average pore size of 5 nm to 5,000 nm and a porosity of 10% or more, said membrane being obtainable by a process comprising curing a composition comprising: (i) a cross-linking agent comprising at least one anionic group; and (ii) inert solvent(s).

The membranes are useful for detecting metal ions and for filtering and/or purifying biomolecules and compositions comprising metal-ions.

An asymmetric hollow fiber (CMS) carbon molecular sieve is made by providing a dope solution comprised of a polvimide and a solvent, at a temperature greater than 250° C. that is less than the storage modulus at a temperature of 250° C., but no more than ten times less as measured using dynamic mechanical thermal analysis from 250° C. to a temperature where the polyimide carbonizes. The polvimide is shaped into a hollow polvimide fiber, the solvent removed and the polyimide hollow fiber is heated to pyroiyze the polvimide and form the asymmetric hollow carbon molecular sieve. The asymmetric hollow fiber carbon molecular sieve has a wall that is defined by an inner surface and outer surface of said fiber and the wall has an inner porous support region extending from the inner surface to an outer raicroporous separation region that extends from the inner porous support region to the outer surface. Surprisingly, when the polyimide has the particular storage modulus characteristics, the method allows for the hollow fiber CMS to be made without any pre-treatmenis or additives to inhibit stractural collapse of the inner microporous region.

Embodiments of the present disclosure describe thin-film composite membranes comprising a crosslinked alginate layer on a surface of a porous woven or non-woven support. Embodiments of the present disclosure further describe methods of preparing membranes, methods of manufacturing membranes, methods of separating chemical species, methods of using the membranes for organic solvent nanofiltration, pervaporation, and the like.

Provided by the present invention is a method for preparing a porous polymer semipermeable membrane, wherein a hydrophobic polynorbornene polymer and a hydrophilic small-molecule crosslinking agent containing a thiol functional group are mixed and dissolved in a solvent capable of dissolving both of them to obtain a coating solution; the coating solution is applied onto the surface of a biosensor electrode and dried such that the hydrophobic component and the hydrophilic component undergo phase separation; then, a membrane is formed and crosslinking is carried out, the unreacted hydrophilic small-molecule crosslinking agent is removed, and re-drying is carried out to obtain a porous polymer semipermeable membrane; also disclosed is a product. For the product obtained by the preparation method of the present invention, the hydrophobicity of the polymer enables good adhesion of the porous polymer semipermeable membrane to the surface of the biosensor, and the porous structure ensures the diffusion of biological substances to the surface of the biosensor, and regulates the diffusion rate of the biological substances in the semipermeable membrane without changing the thickness of the polymer membrane significantly.

The invention relates to membranes, monomers and polymers. The monomers can form polymers, which can be used for membranes. The membranes can be used in alkaline fuel cells, for water purification, for electrolysis, for flow batteries, and for anti-bacterial membranes and materials, as well as membrane electrode assemblies for fuel cells. In addition to the membranes, polymers and monomers and methods of using the membranes, the present invention also relates to methods of making the membranes, monomers and polymers.

A method for forming an isoporous graded film comprising multiblock copolymers and isoporous graded films. The films have a surface layer and a bulk layer. The surface layer can have at least 1×10.sup.14 pores/m.sup.2 and a pore size distribution (d.sub.max/d.sub.min)) of less than 3. The bulk layer has an asymmetric structure. The films can be used in filtration applications.

The invention relates to a method for manufacturing a hollow fiber membrane bundle from a plurality of polysulfone and PVP-based hollow fiber membranes which encompasses the providing of a spinning solution comprising a polysulfone-based material, in particular polysulfone, a vinylpyrrolidone-based polymer, in particular polyvinylpyrrolidone, an aprotic solvent, in particular dimethylacetamide, providing a coagulant liquid comprising water and an aprotic solvent, in particular dimethylacetamide, co-extruding the spinning solution and the coagulant liquid through a concentric annular spinneret into a hollow strand, whereby the cavity of the strand is filled with coagulant liquid, conducting the strand through a precipitation gap, introducing the strand into a precipitating bath comprised substantially of water so as to obtain a hollow fiber membrane, conducting the hollow fiber membranes through at least one rinsing bath and drying the hollow fiber membrane obtained, arranging the resulting hollow fiber membranes into a hollow fiber membrane bundle, and treating the hollow fiber membrane bundle with water vapor.

The present invention relates to a separation membrane including a thermoplastic polymer selected from a cellulose ester and a polyamide, in which, when regions obtained by dividing a cross-sectional surface perpendicular to a longitudinal direction of the separation membrane into 5 at an equal interval are defined as regions 1 to 5, all the regions 1 to 5 have a number average pore diameter changing rate α.sub.i of −0.25 to 0.25, and at least one of the regions 1 to 5 is a region P that satisfies conditions (a) and (b): (a) a value of area average pore diameter D.sub.s/number average pore diameter D.sub.n is 2.50 to 6.00; and (b) a number average W of fine pores that are located at a distance smaller than L.sub.a from a center of respective coarse pores is 10 to 30.