Role of Ion exchange in permeation processes

The single ion transport of transition metal ions like Cu(2+), Co(2+), Ni(2+) and Zn(2+) were carried out through the H(+) and alkali metal ion forms of Nafion membrane. These studies showed that the ion exchange selectivity coefficient of the permeating ion had an effect on its transport process. It was found that the diffusion coefficient values (D) were directly proportional to the selectivity coefficient (K). This shows that the initial stage of permeation is governed by ion exchange process (effect of K on D).