Proton and water transport in nano-separated polymer membranes

The microstructure of proton conducting polymers (NAFION and a sulfonated p olyetherketone) has been investigated by SAXS and the results are related t o coefficients of transport in thermodynamic equilibrium (water-self diffus ion and proton mobility) as well as hydrodynamic transport (water permeatio n and electroosmotic drag) as obtained from NMR, impedance spectroscopic an d permeation experiments. A model comprising (i) simple geometric effects, (ii) effects of chemical interactions and (iii) the formation of inner spac e charges provides a semiquantitative scheme which relates the microstructu re to the transport properties of such types of polymers.