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: 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.

Abstract: Production of coagulated dispersion grades of PTFE using an aqueous emulsion polymerization process which employs an initiator system comprising disuccinic acid peroxide and ammonium sulphite, the latter being added during the course of the polymerization. The resulting polymer can be fabricated into porous products of improved properties.

Abstract: Production of coagulated dispersion grades of PTFE using an aqueous emulsion polymerization process which employs an initiator system comprising disuccinic acid peroxide and ammonium sulphite, the latter being added during the course of the polymerization. The resulting polymer can be fabricated into porous products of improved properties.

Abstract: A composite strip for use in a security system comprises an integrally barbed or serrated carrier strip having a longitudinal groove therein. A fibre-optic filament is disposed in the groove and is held therein by means of an adhesive strip which is applied to the carrier strip so as to overlie the groove. Such a composite strip may provide security against unauthorized crossing of a boundary by directing light into one end of the filament and detecting the light leaving the other end of the filament. An indication is given when the optical intensity of the detected light falls below a predetermined threshold, so as to warn when the fibre-optic filament has been disturbed significantly or cut through.

Abstract: In a security system in which at least one fibre-optic wave guide, which is carried in a strand, extends along a boundary, light is directed into one end of the guide and the light leaving the guide is detected by an optical detector. An indication is given when the intensity of the detected light falls below a predetermined threshold, so as to warn when the wave guide is disturbed significantly or cut through.In order to manufacture the strand, a fibre-optic wave guide is positioned against an elongate carrier and secured to the latter by bonding agent and/or adhesive tape.A dummy strip, having identical external appearance to the strand but not including a fibre-optic wave guide, can also run along the boundary in question.