Abstract: Provided is an ion exchange membrane including an ionic vinyl alcohol polymer having a cation exchange group or an anion exchange group. The ion exchange membrane 1 includes a porous support 3 and the ionic vinyl alcohol polymer. The porous support is provided, in a thickness direction from one surface thereof, with an impregnated layer 2 at least a part of which is impregnated with the ionic vinyl alcohol polymer. The ionic vinyl alcohol polymer includes an ionic vinyl alcohol polymer having an ion exchange group selected from a cation exchange group or an anion exchange group. The ion exchange membrane has a zeta potential value (?1) at one surface and a zeta potential value (?2) at the other surface, which are represented by the formula (1). (|?1|)?|?2|)/|?1|<0.

Abstract: 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.

Abstract: There is provided a multilayered charge-mosaic membrane having a porous supporting layer (A), a porous intermediate layer (B) and a charge-mosaic layer (C), wherein the porous supporting layer (A), the porous intermediate layer (B) and the charge-mosaic layer (C) are located in this order; the porous supporting layer (A) and/or the porous intermediate layer (B) are made of a fiber layer containing hydrophilic fibers; a thickness of the porous intermediate layer (B) is 0.1 to 100 ?m; a porosity of the porous supporting layer (A) is larger than a porosity of the porous intermediate layer (B); the cationic and/or the anionic polymers constituting the charge-mosaic layer (C) is a polyvinyl alcohol having an ionic group. Thus, there is provided a multilayered charge-mosaic membrane having a large salt permeation flux and excellent mechanical strength.

Abstract: There is provided an ion-exchange membrane comprising an ion-exchange layer made of a cationic polymer and/or an anionic polymer and a supporting layer, wherein the ion-exchange layer is formed on the supporting layer by printing. Such an ion-exchange membrane exhibits excellent anti-organic fouling and low membrane resistance, thereby high efficient and long-time stable electrodialysis can be achieved. Formation of the ion-exchange layer as a charge-mosaic layer consisting of the cationic polymer domains and the anionic polymer domains provides a charge-mosaic membrane exhibiting excellent electrolyte permselectivity and mechanical strength.

Abstract: Provided is an ion exchange membrane including an ionic vinyl alcohol polymer having a cation exchange group or an anion exchange group. The ion exchange membrane 1 includes a porous support 3 and the ionic vinyl alcohol polymer. The porous support is provided, in a thickness direction from one surface thereof, with an impregnated layer 2 at least a part of which is impregnated with the ionic vinyl alcohol polymer. The ionic vinyl alcohol polymer includes an ionic vinyl alcohol polymer having an ion exchange group selected from a cation exchange group or an anion exchange group. The ion exchange membrane has a zeta potential value (?1) at one surface and a zeta potential value (?2) at the other surface, which are represented by the formula (1). (|?1|)?|?2|)/|?1|<0.

Abstract: 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.

Abstract: A graft copolymer having a side chain graft-polymerized by atom transfer living radical polymerization (ATRP) on a main chain polymerized by organotellurium-mediated living radical polymerization (TERP), wherein the molecular weight distribution is such that Mw/Mn is 1.5 or less. The graft copolymer is also such that a main chain moiety mainly consisting of the main chain and a side chain moiety mainly consisting of the side chain have microphase-separated structures. The graft copolymer has a narrow molecular weight distribution and forms microphase-separated structures through self organization of hydrophobic and hydrophilic moieties.

Abstract: There is provided a multilayered charge-mosaic membrane having a porous supporting layer (A), a porous intermediate layer (B) and a charge-mosaic layer (C), wherein the porous supporting layer (A), the porous intermediate layer (B) and the charge-mosaic layer (C) are located in this order; the porous supporting layer (A) and/or the porous intermediate layer (B) are made of a fiber layer containing hydrophilic fibers; a thickness of the porous intermediate layer (B) is 0.1 to 100 ?m; a porosity of the porous supporting layer (A) is larger than a porosity of the porous intermediate layer (B); the cationic and/or the anionic polymers constituting the charge-mosaic layer (C) is a polyvinyl alcohol having an ionic group. Thus, there is provided a multilayered charge-mosaic membrane having a large salt permeation flux and excellent mechanical strength.

Abstract: There is provided a charge-mosaic membrane comprising a cationic block copolymer (P) having a vinyl alcohol polymer block (A) and a cationic-group containing polymer block (B) as components; and an anionic block copolymer (Q) having a vinyl alcohol polymer block (C) and an anionic-group containing polymer block (D) as components. Such a charge-mosaic membrane is useful as a charge-mosaic membrane for piezodialysis because it exhibits higher membrane strength and higher permselectivity and has a larger charge density and a larger salt permeation flux.

Abstract: There is provided an ion-exchange membrane comprising an ion-exchange layer made of a cationic polymer and/or an anionic polymer and a supporting layer, wherein the ion-exchange layer is formed on the supporting layer by printing. Such an ion-exchange membrane exhibits excellent anti-organic fouling and low membrane resistance, thereby high efficient and long-time stable electrodialysis can be achieved. Formation of the ion-exchange layer as a charge-mosaic layer consisting of the cationic polymer domains and the anionic polymer domains provides a charge-mosaic membrane exhibiting excellent electrolyte permselectivity and mechanical strength.

Abstract: This invention provides a novel graft polymer that has excellent proton conductivity, is capable of regulating hydrogen permeability, methanol permeability, and the like, and can serve as a starting material for a polymer electrolyte membrane, which facilitates moisture balance control and efficient operation of a fuel cell. A polymer electrolyte membrane composed of such graft polymer is also provided. This graft polymer comprises a main chain comprising a hydroxyl group-containing polymer and a graft chain comprising a polymer containing a sulfonic acid group-containing monomer.

Abstract: A graft copolymer having a side chain graft-polymerized by atom transfer living radical polymerization (ATRP) on a main chain polymerized by organotellurium-mediated living radical polymerization (TERP), wherein the molecular weight distribution is such that Mw/Mn is 1.5 or less. The graft copolymer is also such that a main chain moiety mainly consisting of the main chain and a side chain moiety mainly consisting of the side chain have microphase-separated structures. The graft copolymer has a narrow molecular weight distribution and forms microphase-separated structures through self organization of hydrophobic and hydrophilic moieties.

Abstract: This invention provides a novel graft polymer that has excellent proton conductivity, is capable of regulating hydrogen permeability, methanol permeability, and the like, and can serve as a starting material for a polymer electrolyte membrane, which facilitates moisture balance control and efficient operation of a fuel cell. A polymer electrolyte membrane composed of such graft polymer is also provided. This graft polymer comprises a main chain comprising a hydroxyl group-containing polymer and a graft chain comprising a polymer containing a sulfonic acid group-containing monomer.