State-of-the-Art PEMs and Recent Membrane Development

Proton conductivity in PEMs is usually a strong fimction of the degree of hydration. The maximum conductivity in Nafion ( 0.1 Scm ) is attained with water contents A, 15 (H2O SO3 ratio) imder typical operation conditions. Conductivity decreases monotonically towards lower water content. It usually exhibits a quasi-percolation transition for A, 5 [21,22]. [Pg.18]

Current membrane development focuses on perfluorinated ionomers, hydrocarbon and aromatic polymers and acid-base polymer complexes. Good recent reviews on membrane synthesis and experimental characterization can be found in this volume and for example in [23-29]. [Pg.18]