One embodiment of the present invention provides a hydrophilic composite porous membrane including: a polyolefin microporous membrane, and an olefin/vinyl alcohol-based resin with which at least one main surface and inner surfaces of pores of the polyolefin microporous membrane are coated, in which a ratio t/x of a membrane thickness t (μm) to an average pore diameter x (μm), as measured with a perm porometer, is from 50 to 630.

The present invention provides a strong polymer electrolyte membrane which can provide a water electrolyzer operable at low electrolysis voltage. The polymer electrolyte membrane of the present invention comprises a fluorinated polymer and a woven fabric, wherein the weight of the woven fabric is from 20 to 95 g/m.sup.2, and the warp and weft of the woven fabric independently have a denier of from 30 to 100.

This invention discloses a method for separation of an aromatic compound from a mixture comprising an alkane using an improved thin-film composite membrane. The membrane is particularly useful for separation of benzene from cyclohexane, which have similar boiling points. The membrane comprises a more mechanically durable and defect-free separation layer as a result of its fabrication from an ionomer solution that is substantially free of dissolved ionic species not associated with the ionomer.

A plurality of membrane elements are arranged in series within a pressure vessel in which at least two of the elements exhibit different permeances or selectivities for a gas or gas pair respectively.

A crosslinkable copolymer is provided. The crosslinkable copolymer has pendant cationic nitrogen-containing groups with some, but not all, of these pendant groups further including a (meth)acryloyl group. The (meth)acryloyl groups can react to form a crosslinked copolymer that is ionically conductive. The crosslinked copolymer can be used to provide an anion exchange membrane that can be used in electrochemical cells such as fuel cells, electrolyzers, batteries, and electrodialysis cells.

A filtering device for obtaining a chemical liquid by purifying a liquid to be purified has an inlet portion, an outlet portion, a filter A, at least one filter B different from the filter A, and a flow path which includes the filter A and the filter B arranged in series between the inlet portion and the outlet portion and extends from the inlet portion to the outlet portion, in which the filter A has a porous base material made of polyfluorocarbon and a coating layer which is disposed to cover the porous base material and contains a first resin having a hydrophilic group.

Embodiments of the present disclosure feature an intrinsically microporous ladder-type Tröger's base polymer including a repeat unit based on a combination of W-shaped CANAL-type and V-shaped Tröger's base building blocks, methods of making the intrinsically microporous ladder-type Tröger's base polymer, and methods of using the intrinsically microporous ladder-type Tröger's base polymer to separate a chemical species from a fluid composition including a mixture of chemical species. Embodiments of the present disclosure further include ladder-type diamine monomers for reacting to form a Tröger's base in situ, and methods of making the ladder-type diamine monomers using catalytic arene-norbornene annulation.

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.

[Problem to be Solved]

Provided is a polyvinylidene fluoride resin-made porous membrane having excellent hydrophilicity, permeability, and fouling resistance and having suppressed elution of vinyl ether copolymer by using a small amount of vinyl ether copolymer.

[Means to Solve the Problem]

The porous membrane according to the invention comprises a polyvinylidene fluoride resin as a matrix material and a vinyl ether copolymer, wherein the vinyl ether copolymer is a copolymer of an oxyethylene group-containing vinyl ether monomer and a hydrocarbon group-containing vinyl ether monomer.

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.