Abstract: A hydrophilic cross-linked polymer obtainable by copolymerization of hydrophobic and hydrophilic monomers that give a cross-linked hydrophilic polymer on polymerization; a monomer including a strongly ionic group; and water is useful as the membrane in an assembly that can be used in an electrolyter or fuel cell. More generally, a membrane electrode assembly comprises electrodes and an ion-exchange membrane which comprises a hydrophilic polymer including a strongly ionic group. A method for producing a membrane electrode assembly comprising electrodes and an ion-exchange membrane, comprises introducing between the electrodes a material or materials from which the membrane can be formed, and forming the membrane in situ.

Abstract: A composition, suitable for surgical or dental use, which can expand and/or contract in at least one direction without similar expansion or contraction in another direction, comprises an inner and an outer portion, the portions differing in their expansion properties and/or the extent to which they are prestressed.

Abstract: A composition, suitable for surgical or dental use, which can expand and/or contract in at least one direction without similar expansion or contraction in another direction, comprises an inner and an outer portion, the portions differing in their expansion properties and/or the extent to which they are prestressed.

Abstract: A method for the photoelectrolysis of a liquid or gaseous species, comprises irradiating an ion exchange membrane of a membrane electrode assembly, wherein the membrane is an optically transparent material and comprises the species.

Abstract: A hydrophilic cross-linked polymer obtainable by copolymerisation of hydrophobic and hydrophilic monomers that give a cross-linked hydrophilic polymer on polymerisation; a monomer including a strongly ionic group; and water is useful as the membrane in an assembly that can be used in an electrolyter or fuel cell.

Abstract: An ultrasound probe includes a cross-linked hydrophilic material as an integral couplant, wherein the hydrophilic material is capable of transmitting a frequency in the range of 5 to 20 MHz, and wherein the attenuation of the transmission is less than 1.5 dB.mm−1 at 5 MHz. For example, the invention provides a wheel-type probe, where the hydrophilic material 19 forms the tire.

Abstract: A polymer such as poly(methyl methacrylate) is depolymerized, e.g., to give MMA, by heating the polymer in a fluidized bed at a temperature below the autoignition point of the monomer.

Abstract: A hydrophilic polymer or copolymer is produced in an environment free from a chemical initiator and preferably by irradiation of the starting materials, particularly by gamma rays. The product polymer or copolymer is thus free from the residua of chemical initiators and the method permits the production of polymers and copolymers which are particularly suitable for use in contact with living tissue, for example as contact lenses, prosthetic devices, surgical implants, protective corneal fittings and protective membranes or bandages.