Magnesium titano-antimonate (MgTi5Sb2O16 center dot 12.5H(2)O) and cerium titano-antimonate (Ce(2.7)Ti(5)Sb(2)O(19 center dot)15.0H(2)O) were synthesized as new cation exchangers using the in situ precipitation technique. Physico-chemical investigations showed different behaviors for the obtained materials. The materials have significant stability at high acid concentration and temperature. The ion exchange capacity for Cs+ in the presence of different alcoholic solvents was found to increase and generally obey the order C2H5OH > CH3OH > H2O. Diffusion coefficients (D-i) and thermodynamic parameters of Cs+ exchange in both magnesium and cerium titano-antimonates in aqueous and alcoholic solutions were calculated. The swelling ratios of the materials were predicted by applying modified calculations at constant values of Di. The results showed insignificant swelling behavior in the presence of organic solvents. (C) 2009 Elsevier Inc. All rights reserved.