TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The first conductive polymer comprises thermoplastic or thermoset aromatic polymer; polybenzazole or polyaramid polymer; perfluorinated ionomer; polystyrene sulfonic acid; polytrifluorostyrene sulfonic acid; polyvinyl phosphonic acid; polyvinyl carboxylic acid and polyvinyl sulfonic acid polymers; or their metal salts. The first conductive polymer has a moiety of formulae (I)-(III). At least some of the units (I)-(III) are functionalized to provide ion-exchange sites. The phenyl moieties in units (I)-(III) are optionally substituted and optionally cross-linked. The first conductive material is sulfonated. It is a homopolymer having a repeat unit of formula (IV), (V), (IVasterisk) or (Vasterisk); or a random or block copolymer of at least two different units from (IV), (V), (IVasterisk) or (Vasterisk). It includes at least some ketone moieties in the polymeric chain; a multi-phenylene moiety or a fused ring aromatic moiety which is bonded to two atoms; or a O-biphenylene-O- or -O-naphthalene-O- moiety.m, r, s, t, v, w, z = 0 or positive integer;E, E' = O, S or direct link;G = O, S, direct link or a O-Ph-O- moiety;Ar = (i)asterisk or (i) to (x) which is bonded via of its phenyl moiety or moieties to adjacent moieties;A-D = 0-1Preferred Composition: The first conductive polymer has an equivalent weight (EW) of less than 500 g/mol. The second conductive polymer has an EW of less than 2000.Preferred Property: The second conductive polymer is semi-crystalline.Preferred Method: The support material is contacted with a first solvent, which solubilizes the support material, and a second solvent, which is arranged to cause phase inversion to render the support material porous; and the first conductive polymer is caused to penetrate pores formed in the support material. The first conductive polymer is provided in a third solvent and caused to penetrate the pores.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The composite material incorporates a catalyst material. EXAMPLE - A polymer having a melt viscosity at 400degreesC, 1000 second-1 of 0.54 kNsm-2 was sulfonated by stirring in 98% sulfuric acid (7.5% w/w) for 21 hours at 50degreesC. The reaction solution was cooled at room temperature and cast into a glass plate to produce a 150 mum wet thickness coating. The plate was immersed in deionized water, removed, dried under vacuum at 105degreesC to produce a microporous membrane. The membrane was impregnated with a 15% (w/w) solution of polymer having a melt viscosity of 0.6 kNsm-2 in N-methylpyrrolidone to produce a wet thickness of the solution of 250 mum, and dried for 20 hours at 105degreesC. The composite membrane was strong and flexible, with boiling water uptake of 160%.