Influence of titania morphology on the electrochemical properties of composite polymer electrolyte membranes

摘要

A comparison of the physico-chemical properties of S-PEEK-based composite membranes containing nanometric or mesoporous anatase titania was carried out. The powders were characterized in terms of specific surface area (by B.E.T. apparatus), acidity, and structural features (XRD). Composites containing various amounts of both titania powders (from 1.33 up to 10% wt) were prepared by casting and their water uptake, proton exchange capacity and proton conductivity (EIS) were evaluated. Despite of its lower specific surface area (83 m~2/g) nanometric titania-based composites clearly exhibited higher water absorption properties and superior electrochemical performance with respect to mesoporous titania (SSA = . 147 m~2/g) containing systems. The improvement of membranes performance could be related to the larger number of water-adsorbing acidic sites on the nanometric surface.