Sulfonated Polyphosphazene-Montmorillonite Hybrid Composite Membranes for Fuel Cells

A series of sulfonated polyphosphazene-organic montmorillonite hybrid membranes for direct methanol fuel cells (DMFCs) were prepared. The structure and characteristics of the obtained membranes were studied by testing their X-ray diffraction (XRD), water uptake, water swelling ratio, proton conductivity, thermal properties, methanol permeability and mechanical properties. The morphological analysis of the composite membranes indicated that the organic montmorillonite was uniformly distributed throughout the polymer matrix. Compared to the native sulfonated polyphosphazene membranes, the hybrid membranes showed better mechanical properties and selectivity for proton ions over methanol. The selectivity indicates that polyphosphazene-montmorillonite membranes may be promising electrolyte candidate for direct methanol fuel cells.