Ion-exchange kinetics and electrical conductivity studies of polyaniline Sn(IV) tungstoarsenate; (SnO2)(WO3)(As2O5)4(-C6H5-NH-)2•nH2O:: a new semi-crystalline 'polymeric-inorganic' composite cation-exchange material

A new and novel electrically conducting 'polymeric-inorganic' composite cation-exchange material; polyaniline Sn(IV) tungstoarsenate was prepared by incorporating polyaniline into inorganic ion-exchanger material. It possessed improved ion-exchange capacity, high chemical and thermal stabilities, reproducibility and selectivity for some specific metal ions. Kinetic study of exchange for some divalent metal ions of alkaline earths and transition metals was carried out under the conditions favoring a particle diffusion-controlled ion-exchange phenomenon and some physical parameters such as self diffusion coefficient Do, energy of activation E, and entropy of activation DeltaS* were determined. The temperature dependence of electrical conductivity of this' composite material with increasing temperatures was measured by using 4-in-line-probe DC electrical conductivity measuring-technique. The conductivity values lie in the semiconductor region, i.e. in the range of 10(-3) S cm(-1) that follow the Arrhenius equation. The energy of activation of electrical conduction for the composite was also calculated. (C) 2003 Elsevier Science Ltd. All rights reserved.