Im. Elnaggar et al., THE DIFFUSION MECHANISM OF ALKALI-METAL IONS IN THE PARTICLES OF CERIUM(IV) ANTIMONATE, Solid state ionics, 92(3-4), 1996, pp. 309-315
The kinetic behaviour of Li+, Na+, K+ and Cs+ ions exchange on cerium(
IV) antimonate were investigated under conditions of particle diffusio
n and the limited batch technique. Values for the diffusion coefficien
ts, activation energy and entropy of activation were calculated and th
eir significance were discussed. The values of the effective diffusion
coefficient increased in the order Cs+ > K+ > Na+ > Li+, which parall
els the ionic radii and the ionic mobility. The activation energy (E(a
)) was found to decrease with decreases in the entropy change of the s
ystem. The data obtained for this exchanger were compared with those f
or organic resins and other inorganic ion exchangers.