Electrical Conductivity and NMR Studies of Methanol/Water Mixtures in Nafion Membranes.

摘要: Abstract Complex impedance studies have been carried out in acid form Nafion 117 treated with various amounts of methanol and methanol–water mixtures. At room temperature atmospheric pressure the conductivity for “pure” is about a factor ten less than which contains same wt.% water. In samples water–methanol mixtures, lower having total However, low mixed fluid significantly higher amount water, only, as was mix. This enhancement over that corresponding water uptake attributed to plasticizing effect facilitating segmental motion polymer. concentrations, generally solution-treated be expected since this regime, proton conduction occurs fluid-rich regions, solution case includes large fraction methanol. For 40 1.4:1 molar ratio film, were at pressures up 0.3 GPa. It found electrical decreases increasing pressure. Both activation volume are similar result containing only. Deuteron NMR spin-lattice relaxation measurements isotopically enriched methanol/water mixtures elevated demonstrate greater molecular-level interactions between Nafion. consistent observed results.