The invention is in the field of methods for preparing polymer films, and of such polymer films. The method involves phase separation and requires only aqueous solution, eliminating the need for organic solvents. The aqueous phase separation involves contacting a polymer solution comprising a trigger-responsive polymer with an aqueous coagulation solution in which the trigger-responsive polymer is not soluble.

An anion exchange membrane is composed of a copolymer of 1,1-diphenylethylene and one or more styrene monomers, such as 4-tert-butylstyrene. The copolymer includes a backbone substituted with a plurality of ionic groups coupled to phenyl groups on the backbone via hydrocarbyl tethers between about 1 and about 7 carbons in length. High-temperature conditions enabled by these copolymers enhance conductivity performance, making them particularly suitable for use in anion exchange membranes in fuel cells, electrolyzers employing hydrogen, ion separations, etc. The properties of the membranes can be tuned via the degree of functionalization of the phenyl groups and selection of the functional groups, such as quaternary ammonium groups. Several processes can be used to incorporate the desired ionic functional groups into the polymers, such as chloromethylation, radical bromination, Friedel-Crafts acylation and alkylation, sulfonation followed by amination, or combinations thereof.

Ion exchange membranes obtainable by curing a composition comprising: (a) a monomer comprising an aromatic group and at least one polymerisable ethylenically unsaturated group; (b) a photoinitiator which has an absorption maximum at a wavelength longer than 380 nm when measured in one or more of the following solvents at a temperature of 23° C.: water, ethanol and toluene; and (c) at least one co-initiator.

Cationic polymers are provided that comprise monomeric units of Formula (V). (V) Each asterisk (*) indicates an attachment position to another monomeric unit; R is hydrogen or methyl; each R.sup.2 is each independently an alkyl, aryl, or a combination thereof; L is a linking group comprising an alkylene group; and +R.sup.3 is a cationic nitrogen-containing group free of any N—H bonds. Membranes formed from said cationic polymers, devices including such membranes, and methods of making such cationic polymers are also provided.

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A functional polymer membrane having a pore volume fraction of 0.6% or more and 3.0% or less by allowing a reaction of curing a composition containing a polymerizable compound (A) and a copolymerizable monomer (B).

Provided is a cation exchange membrane having a stable ion exchange performance during usage, being excellent in basic properties such as membrane resistance and ion transportation as well as strength, and useful for electrodialysis and a method for producing the same. The cation exchange membrane is composed of a polyvinyl alcohol copolymer including an anionic group-containing anionic polymer segment and a vinyl alcohol polymer segment, and having a microphase separation structure having a domain size (X) in a range from 0 nm<X≦150 nm. The method is composed of forming a membrane from a polyvinyl alcohol copolymer which is adjusted to contain salts in a proportion that the salt weight (C) relative to the polyvinyl alcohol copolymer weight (P) is [(C)/(P)] of 4.5/95.5 or lower.

An anion exchange membrane is made by mixing 2 trifluoroMethyl Ketone [nominal] (1.12 g, 4.53 mmol), 1 BiPhenyl (0.70 g, 4.53 mmol), methylene chloride (3.0 mL), trifluoromethanesulfonic acid (TFSA) (3.0 mL) to produce a pre-polymer. The pre-polymer is then functionalized to produce an anion exchange polymer. The pre-polymer may be functionalized with trimethylamine in solution with water. The pre-polymer may be imbibed into a porous scaffold material, such as expanded polytetrafluoroethylene to produce a composite anion exchange membrane.

The composite anion exchange membrane includes: a surface layer on a single surface or both surfaces of an anion exchange membrane substrate, in which the above-described surface layer contains a copolymer of a monomer A which is a water-soluble polyfunctional monomer and a monomer B which is a cationic monomer, an anion exchange capacity of the above-described surface layer is 0.05 meq/cm.sup.3 to 0.50 meq/cm.sup.3, and an anion exchange capacity of the above-described anion exchange membrane substrate is 1.0 meq/cm.sup.3 to 5.0 meq/cm.sup.3.

A cation-exchange membrane using a polyolefin-based substrate with reduced swelling of an ion-exchange resin and a low electrical resistance is provided. The cation-exchange membrane of the present invention includes a substrate made of polyolefin-based woven fabric, and a sulfonic acid group-containing cation-exchange resin. A portion of the cation-exchange membrane other than the substrate has 23 mass % or more to 35 mass % or less of polyvinyl chloride.

The present invention is directed to compositions useful for use in separators for use in lithium ion batteries, and membranes, separators, and devices derived therefrom.