SPAES/clay composite membranes with high cation exchange capacity for DMFC systems

Abstract

The cation exchange capacity of clay attributes to a modification possible region and high water affinity itself. In this study, vermiculite which has high cation exchange capacity of ∼150 meq/g with high aspect ratio was used as clay. Sulfonated poly(arylene ether sulfone) (SPAES)/vermiculite composite membranes were prepared by solution casting method and the clay contents in the composite membranes were controlled to 0.5-10wt% based on SPAES. The dispersion of clay particles and the atom composition were investigated by energy dispersive X-ray(EDX) on the cross-section of a membrane. Since protons can be transported along hydrogen-bonded ionic channels in a hydrated membrane, water uptake and water state properties were characterized depending on the clay loading. Proton conductivity and methanol permeability of SPAES/vermiculite composite membranes were also evaluated regarding on the effect of clay dispersion and loading.