The interconnection of ionogenic channel structure, cation hydration, water and ionic translational mobility was revealed in Nafion and MSC membranes based on polyethylene and grafted sulfonated polystyrene. A local mobility of Li+, Na+ and Cs+ cations and water molecules was estimated via the 1H, 7Li, 23Na and 133Cs spin relaxation technique. The calculated cation and water molecule self-diffusion coefficients were compared with experimental values measured using pulsed field gradient NMR. It was shown that macroscopic mass transfer is controlled by molecule and ion motion near sulfonate groups. Lithium and sodium cations whose hydrated energy is higher than water hydrogen bond energy move together with water molecules. Cesium cations in possession of low hydrated energy are directly jumping between neighboring sulfonate groups. Cation Li+, Na+ and Cs+ hydration numbers (h) in membranes were calculated from 1H chemical shift water molecule temperature dependences. The values calculated from the Nernst–Einstein equation and the experimental conductivity values were close to each other in Nafion membranes. In MSC membranes, calculated conductivities were one order of magnitude more compared to the experimental ones, which is explained by the heterogeneity of the membrane pore and channel system.

Abstract Spin-spin and spin-lattice relaxation times of nuclei 69,71Ga, 27Al, 14N in anions [MClnBr4-n]-and the solvate complexes [M(CH3CN)6]3+, produced from dissolution of MCl3 and MBr3 in the mixture CH3CN + CH3NO2 (M = Ga, Al), are measured in the temperature range from -40 up to + 70 °C. It is shown that nuclear spins of 69,71Ga, 27Al relax in the anionic and cationic complexes by means of the second-kind scalar and quadrupole relaxation mechanisms (due to the relaxation of the nuclei 35,37Cl, 79,81Br, 14N). The complexes [MClnBr4-n]-and [M(CH3CN)6]3+ in the investigated solutions are inert and do not undergo exchange processes in the NMR time scale. The scalar spin coupling constants in [M(CH3CN)6]3+ are determined from the scalar contribution to the relaxation rate of 69,71Ga, 27Al, and the measured relaxation time of 14N in the solvate complex; the results are J(69Ga-14N) = 59 ± 5 Hz, J(71Ga-14N) = 74 ± 6Hz, J(27Al-14N) = 22 ± 2Hz.

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