Synthesis and characterization of silicotungstic acid based organic–inorganic nanocomposite membrane

Organic–inorganic composites consisting of silicotungstic acid and poly(vinyl alcohol) were prepared by a sol–gel method. The advantage of this strategy is that it is to manipulate the desired properties such as thermal stability, conductivity. The silicotungstic acid present in the composite acts as acid catalyst to hydrolyze/condense the silica precursor that leads to isotropic composite. The composite is structurally characterized with various techniques such as IR, UV–vis, TGA, SEM, TEM and CV measurements. The proton conductivity of composites is measured using impedance spectroscopy. The conductivity is found to increase with increase in temperature. The activation energy for the proton migration in the composite film was calculated to be 10 kJ/mol.