Patent ID: 8227147

Claim:
A method for making a polymer electrolyte membrane assembly, comprising: a. selecting an aromatic base polymer for an ionically conductive, non-porous base membrane, said aromatic polymer comprising a disulfonated biphenyl poly(arylene ether sulfone), b. selecting an electrode composition to optimize properties exhibited by said polymer electrolyte membrane assembly based on the selection of said base polymer, said electrode composition comprising a catalyst and a proton-conducting polymer, wherein the proton-conducting polymer is different than the base polymer, c. selecting a property-tuning coating layer composition based on compatibility with said base polymer and said electrode composition, wherein said property-tuning coating layer composition is selected from the group consisting of a disulfonated hexafluoro bisphenol A based poly(arylene ether benzonitrile) and a fluorinated poly(arylene ether sulfone), d. selecting a solvent based on the interaction of said solvent with said base polymer and said property-tuning coating layer composition, and mixing said solvent with said property-tuning coating layer composition, e. preparing said base membrane for application of said property-tuning coating layer composition, f. applying said property-tuning coating layer composition to said base membrane, g. preparing said property-tuning coating layer composition for application of said electrode composition, h. applying said electrode composition to said property-tuning coating layer.