Properties in Dilute Solution Environments

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- 

Exchange-Site Concentration and Water Content for Perfluorinated lonomer Membranes  

Membrane Exchange-site concentration Mol H20/mol exchange site  

Self-diffusion coefficients for sodium ion, cesium ion, and water in these polymers are shown in Fig. 9, as Arrhenius plots from 0 to Diffusion of sodium ion and water is remarkably similar 

Self-diffusion coefficients of polyvalent cations in these perfluorinated ionomer membranes have not been reported. It can be inferred from the use of the sulfonate membranes as Donnan dialysis devices that transport of cations such as CuflT), Mg(II), and Al(III) under a concentration gradient is rapid. Also, column chromatographic separation of the alkaline-earth ion is readily accomplished with a powdered Nafion perfluorosulfonate polymer, which is again an indication of facile diffusion of these cations within the polymer phase. 

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