Transport properties of materials based on MF-4SC membranes and silica manufactured by a casting method

Composites based on MF-4SC perfluorinated cation-exchange membranes were manufactured by casting from a polymer solution with a precursor for subsequent use in the synthesis of hydrous silica. Their proton conductivity was studied as a function of composition, temperature, and relative humidity. Modification of MF-4SC with small dopant amounts increases the water content and ion conductivity, in a reduced humidity, too. Materials containing 3% SiO₂ by weight have a maximal conductivity.