A composite membrane comprising: a) a first layer comprising a first porous support and a first ionic polymer present in the pores of the first porous support; b) a second layer comprising a second porous support and a second ionic polymer present in the pores of the second porous support; c) a third layer comprising a third porous support, a third ionic polymer and a fourth ionic polymer, wherein the third ionic polymer is present in the pores of the third porous support; wherein: (i) one of the first ionic polymer and the second ionic polymer is a cationic polymer and the other is an anionic polymer; (ii) the third layer c) is interposed between the first layer a) and the second layer b); (iii) the third ionic polymer comprises a network of pores and the fourth ionic polymer is present within the pores of the third ionic polymer; and (iv) one of the third ionic polymer and the fourth ionic polymer is a cationic polymer and the other is an anionic polymer.

A polymer film obtainable by curing a composition comprising a compound of Formula (I) wherein: R′ is vinyl, epoxy C.sub.1-3_alkylenethiol: n has a value of 1 or 2; m has a value of 1, 2 or 3; M′.sup.+ is a cation; wherein X is as defined in the claims; and wherein the molar fraction of the compound of Formula (I) in relation to all curable compounds in the composition is greater than 0.25. Also claimed are compositions, processes membranes and their uses.

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A membrane comprising: a) a first layer comprising a first polymer or a fourth polymer having ionic groups of polarity opposite to the polarity of the ionic groups of the third polymer; b) a second layer comprising a second polymer having ionic groups of polarity the same as the polarity of the ionic groups of the third polymer; and c) a third layer comprising a co-continuous polymeric network of (i) a third polymer having ionic groups and a network of pores; and (ii) a fourth polymer having ionic groups of polarity opposite to the polarity of the ionic groups of the third polymer; wherein layer c) is interposed between layer a) and layer b) and the third polymer is obtainable by a process comprising phase separation of the third polymer from a curable composition used to prepare the third polymer.

Multicomponent copolymers including two or more types of repeat units is presented. In one example, the multicomponent copolymer includes at least one repeat unit AC having a structure (I), at least one repeat unit DC having a structure (II), and at least one repeat unit BC having a structure (III) or (V). The multicomponent copolymer may be cross-linked via a cross-linking agent. A polymer blend including the multicomponent copolymer or a cross-linked copolymer and a second polymer is also provided. The multicomponent copolymer may be a random or a block copolymer. The structural units of the multicomponent copolymers provide improved, tunable properties, such as improved biocompatibility and hydrophilicity, protein fouling, and mechanical properties, to the copolymers and/or the membranes fabricated from the copolymers.

Disclosed is a statistical copolymer that includes both zwitterionic repeat units and hydrophobic repeat units, and a filtration membrane that contains a selective layer formed of the statistical copolymer. Also disclosed are methods of preparing the above-described filtration membrane.

Provided are a monovalent anion selective ion exchange membrane and a method of manufacturing the ion exchange membrane. In regard to the monovalent anion selective ion exchange membrane, a surface portion thereof has a high amount ratio of a cation exchange polymer electrolyte, a central portion thereof has a high amount ratio of an anion exchange polymer electrolyte, and an amount ratio of the anion exchange polymer electrolyte with respect to the cation exchange polymer electrolyte continuously increases in the thickness direction thereof from the surface toward the center. Due to this structure, compared to monovalent anions, polyvalent anions may permeate much less through the exchange membrane. Thus, high selectivity for monovalent anions may be obtained.

Multicomponent copolymers including two or more types of repeat units is presented. In one example, the multicomponent copolymer includes at least one repeat unit AC having a structure (I), at least one repeat unit DC having a structure (II), and at least one repeat unit BC having a structure (III) or (V). The multicomponent copolymer may be cross-linked via a cross-linking agent. A polymer blend including the multicomponent copolymer or a cross-linked copolymer and a second polymer is also provided. The multicomponent copolymer may be a random or a block copolymer. The structural units of the multicomponent copolymers provide improved, tunable properties, such as improved biocompatibility and hydrophilicity, protein fouling, and mechanical properties, to the copolymers and/or the membranes fabricated from the copolymers.

Disclosed are linear/random/statistical copolymers comprising three types of monomeric units: hydrophobic monomeric units, zwitterionic monomeric units, and charged or ionizable monomeric units. Also provided are thin film composite membranes whose selective layer is comprised of the copolymers disclosed herein, and the methods of use thereof.

The present disclosure provides a porous polymeric membrane that is coated with a cross-linked polymerized monomer. The coating on the porous polymeric membrane has a charge when it is immersed in an organic liquid. The coated porous polymeric membrane, a filter utilizing the membrane, and a method for treating an organic liquid used for photoresist with the coated porous polymeric membrane to remove metal contaminants from the organic liquid are disclosed.

A membrane filter is provided. The membrane filter including an ordered functional nanoporous material (OFNM) defining a layer and a membrane support. The layer having a two-dimensional structure and defining a plurality of pores and imparting to the membrane filter a permeance of at least 900 Lm.sup.−2h.sup.−1bar.sup.−1 and a rejection of at least 60% as to a solvent containing a filterable species.