Perfluorocarboxylic acid membrane exchange capacity

Water Content. Figure 4 shows the relation between the water content of perfluorocarboxylic acid membrane prepared by chemical treatment and the ion exchange capacity with varying external solution concentration. As the concentration of the external solution increases, the membrane shrinkage increases and the water content is therefore decreased. The influence of... 

Water content in Figure 4 can be expressed as a function of ion exchange capacity and external solution concentration by the following empirical equation, which is similar to that proposed for perfluorosulfonic acid membranes by W.G.F. Grot in 1972 (44). The water content of perfluorocarboxylic acid membrane is much lower than that of perfluorosulfonic acid membrane. 

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

As a result, the perfluorocarboxylated membrane with a high ion exchange capacity attains a high fixed ion concentration, which is defined as milliequivalent of carboxylic acid group per a gram of absorbed water in the membrane. 

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