Research trends: Evaluation of methanol crossover in proton-conducting polyphosphazene membranes

Methanol permeation was compared in new phosphonated polyphosphazene membranes with Nafion® 117 and sulfonated polyphosphazene membranes. A diffusion cell was developed to evaluate methanol crossover for a novel class of polyphosphazene electrolyte membranes. The methanol diffusion coefficients of phenyl phosphonic acid functionalized poly[aryloxyphosphazene] membranes in an aqueous methanol solution (50 vol %) were 40 times lower than for Nafion 117, and ∼ 10-20 times lower than for sulfonated polyphosphazene membranes. This is an abstract of an article originally published in Materials Letters 52(3) 192-196 (January 2002).