Proton and water transport in nano-separated polymer membranes

Abstract
The microstructure of proton conducting polymers (NAFION and a sulfonated polyetherketone) has been investigated by SAXS and the results are related to coefficients of transport in thermodynamic equilibrium (water-self diffusion and proton mobility) as well as hydrodynamic transport (water permeation and electroosmotic drag) as obtained from NMR, impedance spectroscopic and permeation experiments. A model comprising (i) simple geometric effects, (ii) effects of chemical interactions and (iii) the formation of inner space charges provides a semiquantitative scheme which relates the microstructure to the transport properties of such types of polymers.