Mobility of water molecules in Li+, Na+ and Cs+ ionic forms of Nafion membrane studied by NMR.

[Display omitted] Correlation times and diffusion coefficients of water molecules were measured for the first time by 1H spin relaxation and pulsed field gradient NMR in Li+, Na+ and Cs+ ionic forms of Nafion 117 membrane. Hydration numbers of Li+, Na+ and Cs+ cations were calculated. It was shown that at high humidity macroscopic transfer is controlled by the local translational motion of water molecules. [ABSTRACT FROM AUTHOR]