NOVELTY - The thermally stable proton conductive composite comprises an acid and/or an organic base and a layered/framework silicate.    USE - The composite is useful for proton conductive membranes in membrane fuel cells (e.g. H2 fuel cells and DMFCs), in membrane separation processes such as electrodialysis, diffusion dialysis, gas separation, pervaporation, perstraction, micro-, ultra- and nano-filtration and reverse osmosis, as a catalytic membrane, in electrolysis (PEM electrolysis or chlor-alkali electrolysis) or in electrochemical processes.    ADVANTAGE - The composite allows incorporation of organic components, especially proton conductive nitrogen bases, in the cavities of the silicate to provide a further cross-linking component and allows targeted incorporation of cations or metal hydroxides with subsequent sintering to metal oxides which permit wide variation of Lewis acid properties and membrane cavity sizes. Additionally, the composite has good ion conductivity even at well above 100 degrees C, has increased chemical, mechanical and thermal stability, exhibits reduced methanol permeation and transverse gas diffusion in DMFCs, exhibits much reduced fouling (microbial attack by mould and bacteria) and has catalytic properties provided by the silicate Lewis acids.    DETAILED DESCRIPTION - The proton conductive composite comprises 1-99 wt.% acid and/or organic base and 99-1 wt.% layered/framework silicate and is thermally stable at up to 400 degrees C.    INDEPENDENT CLAIMS are also included for the following:    (i) the production of composites and composite blend membranes by mixing a solution of an ionomer (precursor), as defined below, with layered and/or framework silicate and evaporating the solvent; and    (ii) ionic non-conductive composites and composite blend membranes obtained from 20-98 wt.% of basic polymer, described below, and 2-80 wt.% layered/framework silicate, for use in membranes and membrane separation processes.    DESCRIPTION OF DRAWING(S) - The drawing shows the production of a pillared clay.