Abstract: A process for preparing an ion-exchange membrane having a textured surface profile comprising the steps (i) and (ii): (i) screen-printing a radiation-curable composition onto a membrane in a patterned manner; and (ii) irradiating and thereby curing the printed, radiation-curable composition; wherein the radiation-curable composition has a viscosity of at least 30 Pa·s when measured at a shear rate of 0.1 s?1 at 20° C.

Abstract: A process for preparing an ion-exchange membrane having a textured surface profile comprising the steps (i) and (ii): (i) applying a radiation-curable composition to a membrane in a patternwise manner; and (ii) irradiating and thereby curing the radiation-curable composition present on the membrane; wherein the radiation-curable composition comprises: a) 10 to 65 wt % of curable ionic compound(s) comprising one ethylenically unsaturated group; b) 3 to 60 wt % of crosslinking agent(s) comprising at least two ethylenically unsaturated groups and having a number average molecular weight below 800; c) 0 to 70 wt % of inert solvent(s); d) 0 to 10 wt % of free-radical initiator(s); and e) 0.5 to 25 wt % of thickening agent(s).

Abstract: A membrane obtainable from curing a composition comprising: (i) a curable compound comprising at least two (meth)acrylic groups and a sulphonic acid group and having a molecular weight which satisfies the equation: MW<(300+300n) wherein: MW is the molecular weight of the said curable compound; and n has a value of 1, 2, 3 or 4 and is the number of sulphonic acid groups present in the said curable compound; and optionally (ii) a curable compound having one ethylenically unsaturated group; wherein the molar fraction of curable compounds comprising at least two (meth)acrylic groups, relative to the total number of moles of curable compounds present in the composition, is at least 0.25.

Abstract: A process for preparing an ion-exchange membrane having a textured surface profile comprising the steps (i) and (ii): (i) applying a radiation-curable composition to a membrane in a patternwise manner; and (ii) irradiating and thereby curing the radiation-curable composition present on the membrane; wherein the radiation-curable composition comprises: a) 10 to 65 wt % of curable ionic compound(s) comprising one ethylenically unsaturated group; b) 3 to 60 wt % of crosslinking agent(s) comprising at least two ethylenically unsaturated groups and having a number average molecular weight below 800; c) 0 to 70 wt % of inert solvent(s); d) 0 to 10 wt % of free-radical initiator(s); and e) 0.5 to 25 wt % of thickening agent(s).

Abstract: A process for preparing a membrane stack comprising the steps of: (i) interposing a curable adhesive between alternate anion exchange membranes and cation exchange; and (ii) curing the adhesive; CHARACTERIZED IN THAT said adhesive, when cured, has a Shore A hardness of less than 70 and an elongation at break of at least 50%.

Abstract: A disposable, crossflow membrane stack suitable for use in an ion exchange unit, the stack comprising alternate dilution compartments and concentration compartments, each compartment being defined by a flat cation-permeable membrane (2) and a flat anion-permeable membrane (1) and at least two edges along which the cation-permeable and an anion-permeable membranes are permanently secured together wherein the cation-permeable membranes and/or the anion-permeable membranes have a textured surface profile which keep said membranes apart and/or from touching each other and wherein the edges secured together define the direction in which liquid may flow through the compartments. Also claimed are ion exchange units comprising the stack, optionally comprising a quick-release securement means to allow facile attachment and release of modular units comprising the stacks.

Abstract: A process for preparing a membrane stack comprising the steps of (i) interposing a curable adhesive between alternate anion exchange membranes and cation exchange; and (ii) curing the adhesive; CHARACTERIZED IN THAT said membranes are in a swollen state when step (ii) is performed.

Abstract: A membrane obtainable from curing a composition comprising: (i) a curable compound comprising at least two (meth)acrylic groups and a sulphonic acid group and having a molecular weight which satisfies the equation: MW<(300+300n) wherein: MW is the molecular weight of the said curable compound; and n has a value of 1, 2, 3 or 4 and is the number of sulphonic acid groups present in the said curable compound; and optionally (ii) a curable compound having one ethylenically unsaturated group; wherein the molar fraction of curable compounds comprising at least two (meth)acrylic groups, relative to the total number of moles of curable compounds present in the composition, is at least 0.25.

Abstract: A membrane obtainable from curing a composition comprising: (i) a curable compound comprising at least two (meth)acrylic groups and a sulphonic acid group and having a molecular weight which satisfies the equation: MW<(300+300n) wherein: MW is the molecular weight of the said curable compound; and n has a value of 1, 2, 3 or 4 and is the number of sulphonic acid groups present in the said curable compound; and optionally (ii) a curable compound having one ethylenically unsaturated group; wherein the molar fraction of curable compounds comprising at least two (meth)acrylic groups, relative to the total number of moles of curable compounds present in the composition, is at least 0.25.

Abstract: A process for preparing a membrane stack comprising the steps of: (i) interposing a curable adhesive between alternate anion exchange membranes and cation exchange; and (ii) curing the adhesive; CHARACTERISED IN THAT said adhesive, when cured, has a Shore A hardness of less than 70 and an elongation at break of at least 50%.

Abstract: A process for preparing a membrane stack comprising the steps of (i) interposing a curable adhesive between alternate anion exchange membranes and cation exchange; and (ii) curing the adhesive; CHARACTERISED IN THAT said membranes are in a swollen state when step (ii) is performed.

Abstract: A process for preparing an ion-exchange membrane having a textured surface profile comprising the steps (i) and (ii): (i) screen-printing a radiation-curable composition onto a membrane in a patterned manner; and (ii) irradiating and thereby curing the printed, radiation-curable composition; wherein the radiation-curable composition has a viscosity of at least 30 Pa·s when measured at a shear rate of 0.1 s?1 at 20° C.

Abstract: A process for preparing an ion-exchange membrane having a textured surface profile comprising the steps (i) and (ii): (i) applying a radiation-curable composition to a membrane in a patternwise manner; and (ii) irradiating and thereby curing the radiation-curable composition present on the membrane; wherein the radiation-curable composition comprises: a) 10 to 65 wt % of curable ionic compound(s) comprising one ethylenically unsaturated group; b) 3 to 60 wt % of crosslinking agent(s) comprising at least two ethylenically unsaturated groups and having a number average molecular weight below 800; c) 0 to 70 wt % of inert solvent(s); d) 0 to 10 wt % of free-radical initiator(s);and e) 0.5 to 25 wt % of thickening agent(s).

Abstract: A device selected from the group consisting of an electrodialysis or reverse electrodialysis unit, an electrodeionization module and a flow through capacitor, the device comprising a membrane obtained from a process comprising the following steps: applying a curable composition to a support; and curing the composition to form a membrane; wherein the curable composition comprises: (i) 2.5 to 50 wt % crosslinker comprising at least two acrylamide groups; (ii) 12 to 65 wt % curable ionic compound comprising an ethylenically unsaturated group and a cationic group; (iii) 10 to 70 wt % solvent; (iv) 0 to 10 wt % of free radical initiator; and (v) non-curable salt comprising a cation and an anion, wherein the anion is not sulfate; wherein the molar ratio of (i):ii) is greater than 0.10 and less than 5.

Abstract: A disposable, crossflow membrane stack suitable for use in an ion exchange unit, the stack comprising alternate dilution compartments and concentration compartments, each compartment being defined by a flat cation-permeable membrane (2) and a flat anion-permeable membrane (1) and at least two edges along which the cation-permeable and an anion-permeable membranes are permanently secured together wherein the cation-permeable membranes and/or the anion-permeable membranes have a textured surface profile which keep said membranes apart and/or from touching each other and wherein the edges secured together define the direction in which liquid may flow through the compartments. Also claimed are ion exchange units comprising the stack, optionally comprising a quick-release securement means to allow facile attachment and release of modular units comprising the stacks.

Abstract: A curable composition comprising: (i) 2.5 to 50 wt % crosslinker comprising at least two acrylamide groups; (ii) 20 to 65 wt % curable ionic compound comprising an ethylenically unsaturated group and an anionic group; (iii) 15 to 45 wt % solvent; and (iv) 0 to 10 wt % of free radical initiator; wherein the molar ratio of (i):(ii) is 0.1 to 1.5. The compositions are useful for preparing ion exchange membranes.

Abstract: A curable composition comprising: (i) 2.5 to 50 wt % crosslinker comprising at least two acrylamide groups; (ii) 12 to 65 wt % curable ionic compound comprising an ethylenically unsaturated group and a cationic group; (iii) 10 to 70 wt % solvent; and (iv) 0 to 10 wt % of free radical initiator; and (v) non-curable salt; wherein the molar ratio of (i):(ii) is >0.10. The compositions are useful for preparing ion exchange membranes.

Abstract: A curable composition comprising: (i) 2.5 to 50 wt % crosslinker comprising at least two acrylamide groups; (ii) 20 to 65 wt % curable ionic compound comprising an ethylenically unsaturated group and an anionic group; (iii) 15 to 45 wt % solvent; and (iv) 0 to 10 wt % of free radical initiator; wherein the molar ratio of (i):(ii) is 0.1 to 1.5. The compositions are useful for preparing ion exchange membranes.

Abstract: A membrane obtainable from curing a composition comprising (i) a curable compound comprising at least two acrylic groups and a quaternary ammonium group; (ii) solvent; and optionally (iii) a curable compound having one ethylenically unsaturated group.

Abstract: A curable composition comprising: (i) 2.5 to 50 wt % crosslinker comprising at least two acrylamide groups; (ii) 12 to 65 wt % curable ionic compound comprising an ethylenically unsaturated group and a cationic group; (iii) 10 to 70 wt % solvent; and (iv) 0 to 10 wt % of free radical initiator; and (v) non-curable salt; wherein the molar ratio of (i):(ii) is >0.10. The compositions are useful for preparing ion exchange membranes.