on 70 sulfonated speek increases from 48 to 143 for composite membranes based on 74 sulfonated speek increased from 62 to 190 and the water uptake of the composite membranes based on 80 speek increased to high value from 120 to 600 it is worth noting however that the increased water uptake associated with the incorporation of hpas to the polymer matrix is only one factor affecting the membrane conductivity other factors including the polymer intrinsic conductivity strength density and softness of the solid acid sites the solid phase loading particle size and spatial distribution the aqueous phase dispersion all membranes which are described as a nanoporous inert u201c sponge u201d for water of hydration this water shows little interaction with the polymer chain and forms hydration shells around the sulfonic acid groups 25 in hpa speek membranes the aqueous phase is more continuous this leads to higher water uptake swelling an contributes to a greater extent to proton conductivity examples of arrhenius plots of conductivity for the 70 speek based composite membranes are given in fig1 for all composite membranes reported here the activation energy for proton conduction was similar and close to 15 kj mol this result suggests a common charge transfer mechanism the relatively low measured values of activation energy are suggestive of a liquid like mechanism most probably based on the grotthus reorientational proton transfer scheme 4 of note the conductivity of composite membranes was not affected by storage in water at room temperature for nine months speek.