摘要:
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.
摘要:
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.
摘要:
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
摘要:
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 µm; 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.
摘要:
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 (ζ1) at one surface and a zeta potential value (ζ2) at the other surface, which are represented by the formula (1). ζ 1 - ζ 2 / ζ 1 0.5 ζ 1 ≥ ζ 2
摘要:
A vinyl alcohol polymer-containing coating agent for paper is provided that allows a curing step to be omitted after a paper surface is coated therewith and makes it possible to form a layer (for example, a coating layer or a color developing layer) that is excellent in water resistance and is subjected to less yellowing over time. It is an aqueous composition containing a vinyl alcohol polymer (A) in which the content X of vinyl alcohol units (mol%) and the content Y of ethylene units (mol%) satisfy a formula X+0.2Y>95, where X
摘要:
This invention provides a vinyl alcohol polymer-containing coating agent for paper, which, despite the fact that a curing step after coating the coating agent onto a paper surface can be omitted, can form a layer (for example, a coating layer or a color developing layer) having excellent water resistance and having no significant susceptibility to yellowing with the elapse of time. The coating agent is an aqueous composition comprising a vinyl alcohol polymer (A) satisfying a formula “X + 0.2Y > 95”, wherein X represents the content of vinyl alcohol units, % by mole; and Y represents the content of ethylene units, % by mole, and an addition condensation product (B) between ethylene urea and glyoxal. In the addition condensation product (B), the content of the terminal aldehyde group per g of the solid is 1.2 to 3.0 (mmol). The weight ratio on a solid basis between the vinyl alcohol polymer (A) and the addition condensation product (B) is in the range of (A) : (B) = 99 : 1 to 50 : 50. In the above formula, X
摘要:
The present invention provides an electrode comprising a current collector layer, a porous electrode layer and an ion exchange layer which are arranged in this order, wherein the ion exchange layer contains a vinyl alcohol copolymer (P) copolymerized with 0.1 to 50 mol% of a monomer having an ionic group and the porous electrode layer contains a carbon material. This electrode has a low electrode resistance, and, therefore, is useful as an electrode for a flow-through capacitor.
摘要:
There is provided an anion exchange membrane comprising, as a main element, a block copolymer having a vinyl alcohol polymer block and a cationic-group containing polymer block as components and which is subjected to a crosslinking treatment. An anion exchange membrane is produced by heating a film obtained from a solution of the block copolymer at a temperature of 100 °C or more, crosslinking the film with a dialdehyde compound in water, an alcohol or a mixture of these under an acidic condition and then washing the film with water. Thus, there can be provided an anion exchange membrane in which organic fouling can be prevented and which exhibiting excellent basic properties such as a membrane resistance and an ionic transport number and excellent membrane strength.