Perfluorocarboxylic acid membrane electric resistance

Figure 9. Electric resistance, ion exchange capacity (meq/g dry resin) and concentration of NaOH, for perfluorocarboxylic acid membrane prepared by chemical...

The typical perfluorocarboxylic acid membrane developed by Asahi Chemical is a multilayer membrane prepared by chemical treatment. The structure of the membrane is optimized for high current efficiency and low electric resistance. The thickness of the carboxylic acid layer is in the range of 2 to 10 microns. The chemical structure of the membrane is as follows (72). 

The weak acidity and relatively low hydrophilicity of the perfluorocarboxylic acid group results in a very high current efficiency of over 96%, although its electric resistance is high (1, 3, 5, T y 10, 26-29). The membrane can be exposed to fairly acidic solution as the pKa value is around 2. Its chemical stability is quite good under electrolysis conditions. 

Figure 2. The thickness of CO OH layer, current efficiency, and electric resistance of a multilayer perfluorocarboxylic and sulfonic acid membrane prepared by chemical treatment (COOH/SOsH).

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