Proton-Conducting Composite Membranes Based on Sulfonated Poly(ether sulfone) and Sur- face-Modified Tin Phosphate

Organic/inorganic composite membranes were prepared by dispersing m-sulfophenyl-group-modified layered tin phosphate hydrate particles (SnPP-SPP) or nanosheets (SnPNS-SPP) in sulfonated poly(ether sulfone) (SPES). The chemical stabilities, as evaluated by Fourier-transform infrared spectroscopy and water-uptake measurements, were improved by dispersion of SnPP-SPP or SnPNS-SPP into the SPES matrix. The proton-conducting properties of the composite membranes were improved by the sulfophenyl group modification; among the composite membranes, the membrane containing 10 vol% SnPNS-SPP showed the highest conductivity of 8.0 × 10 −2 S cm −1 at 150 °C under saturated water-vapor pressure. KeywordsOrganic/Inorganic Nanocomposite; Proton Conductors; Fuel Cell