Abstract: A polymer electrolyte membrane or gas diffusion electrode includes an ion-conducting polymeric material which includes moieties of formula (A) which are substituted on average with more than 1 and 3 or fewer groups (e.g. sulphonate groups) which provide ion-exchange sites and hydrogen atoms of said moieties are optionally substituted, wherein each X in said moieties of formula A independently represent an oxygen or sulphur atom. The ion conducting polymeric material is suitably prepared by controllably sulphonating a polymeric material using about 100% sulphuric acid at 34° C. to 36° C.

Abstract: A polymer electrolyte membrane or gas diffusion electrode includes an ion-conducting polymeric material which includes moieties of formula (A) which are substituted on average with more than 1 and 3 or fewer groups (e.g. sulphonate groups) which provide ion-exchange sites and hydrogen atoms of said moieties are optionally substituted, wherein each X in said moieties of formula A independently represent an oxygen or sulphur atom. The ion conducting polymeric material is suitably prepared by controllably sulphonating a polymeric material using about 100% sulphuric acid at 34° C. to 36° C.

Abstract: An ion-exchange material, for example a polymer electrolyte membrane or gas diffusion electrode comprises a semi-crystalline copolymer comprising: a first unit which includes an ion-exchange site; a second crystalline unit; and a third unit which is amorphous. The third unit is used to disrupt the crystallinity of the copolymer thereby to increase its solubility in solvents. The material described may be used in fuel cells.

Abstract: A method of preparing an ion-conducting material, for example membrane, having reduced sensitivity to water includes a step of treating an ion-conducting polymeric material (especially a sulphonated polyaryletherketone and/or sulphone) which has at least some crystallinity or which is crystallizable with a means to increase its crystallinity. The ion-conducting material prepared may be used in a Membrane Electrode Assembly of a fuel cell.

Abstract: A composite material, for example a composite membrane for a polymer electrolyte membrane fuel cell includes a first conductive polymer and a support material for the polymer, wherein the support material comprises a second conductive polymer. A method making of the composite material is also disclosed as is its use as a polymer electrolyte membrane in a fuel cell.

Abstract: Ion-Exchange polymers for a polymer electrolyte membrane include a moiety of formula (I), and/or a moiety of formula (II), and/or a moiety of formula (III) wherein at least some of the units I, II and/or III are sulphonated. The phenyl moieties in units I, II, and III are independently optionally substituted and optionally cross-linked; m, r; s, t, v, w and z independently represent zero or a positive integer, E and E′ independently represent an oxygen or a sulphur atom or a direct link, G represents an oxygen or sulphur atom, a direct link or a —O—Ph—O— moiety where Ph represents a phenyl group and Ar is selected from one of the moieties (i) to (x) as set forth herein which is bonded via one or more of its phenyl moieties to adjacent moieties.

Abstract: An ion-exchange material, for example a polymer electrolyte membrane or gas diffusion electrode comprises a semi-crystalline copolymer comprising: a first unit which includes an ion-exchange site; a second crystalline unit; and a third unit which is amorphous. The third unit is used to disrupt the crystallinity of the copolymer thereby to increase its solubility in solvents. The material described may be used in fuel cells.

Abstract: A method of preparing an ion-conducting material, for example membrane, having reduced sensitivity to water includes a step of treating an ion-conducting polymeric material (especially a sulphonated polyaryletherketone and/or sulphone) which has at least some crystallinity or which is crystallisable with a means to increase its crystallinity. The ion-conducting material prepared may be used in a Membrane Electrode Assembly of a fuel cell.

Abstract: A composite material, for example a composite membrane for a polymer electrolyte membrane fuel cell includes a first conductive polymer and a support material for the polymer, wherein the support material comprises a second conductive polymer. A method making of the composite material is also disclosed as is its use as a polymer electrolyte membrane in a fuel cell.