Membrane cesium-sulfonate

Figure 10. Typical oscilloscope traces showing variations of the ionic SAXS profiles upon stretching the cesium-sulfonate membranes having 1100 EW under dry state in a direction (left) parallel (n = 0°) and (right) perpendicular (V = 90°) to stretching direction X is draw ratio of the membranes. Key 1, X = 1.0 2,1 — 1.1 3, X = 1.2 4, X = 1.3 5, X = 1.5.

Soldatov, V., Oedberg, L., Hogfeldt, E. Infrared and NMR studies of lithium and cesium salts of dinonylnaphthalene sulfonic acid in heptane. In Ion exchange and membranes. 

The self-diffusion coefficients of sodium and cesium ions have been measured for perfluorinated sulfonate (Nafion ) and carboxylate membranes of similar structure. The exchange-site con-... 

Perhaps the simplest modification of Nafion for DMFCs was carried out by Tricofi [28], who doped Nafion 117 with Cs cations. The decrease in size of hydrated micellar domains, upon snbstituting a portion of the membranes sulfonate sites with cesium, caused the methanol permeability to fall. The ratio of proton conductivity to methanol permeability, which reflects membrane selectivity, increased by a factor of 2.5 when Nafion 117 in the H+ form was fnlly exchanged with cesium. To prevent cesium fiom leaching ont of the membrane during fuel cell operation, Tricofi proposed adding a suitable amount of Cs salt to the methanol/water feed mixture. 

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