New polymeric electrolyte membranes based on proton donor-proton acceptor properties for direct methanol fuel cells

In order to reduce the high methanol permeability of membranes in a direct methanol fuel cell application new and better materials are still required. In this paper membranes made from polybenzimidazole/sulfonated polysulfone are given and compared with homopolymer membranes made from sulfonated polysulfone, blends of polyethersulfone with sulfonated polysulfone and Nafion N117. Various methods of characterization have been used such as swelling measurements, ion exchange capacity (I.E.C.), electrical resistance, permselectivity, sorption isotherms and methanol permeability which give information on the conductive properties and methanol permeability properties of the membranes. These methods were used as a first estimate to give information about what kind of material is better to be used in a direct methanol fuel cell application.