A novel composite membranes based on sulfonated montmorillonite modified Nafion® for DMFCs

A novel functional organoclay was prepared using POP-backboned quaternary ammonium salts that contained sulfonic acid (–SO3H) to improve the performance of Nafion® membranes used in direct methanol fuel cells. Modified layered silicate clays were cast with Nafion®. The performance of the Nafion®/MMT-POPD400-PS composite membranes was evaluated in terms of methanol permeability, proton conductivity and cell performance. The methanol permeability of the composite membrane declined as the MMT-POPD400-PS content increased. The MMT was functionalized using organic sulfonic acid to enhance proton conductivity. The proton conductivity of the composite membrane exceeded that of pristine Nafion®. These effects essentially improved the single-cell performance of DMFC.