Ionic conductivity of alkali halides across a polyaniline-zirconium (iv)-arsenate membrane

Abstract

In continuation to our previous work with composite polyaniline-zirconium (IV)-arsenate (PZA), we further extended with the conductivity measurements in this report. All the calculations reported in here were extracted from the experiments carried out in the temperature range of (25-50)±0.1°C and at different concentrations (0.01≤C(M) ≤1) of KCl, NaCl and LiCl 1-1 electrolyte solutions. The diffusion coefficient for 1-1 electrolyte solutions was found to decrease in the order K+> Na+> Li+, which is in accordance with a decrease in the size of cation. The resistance is decreasing with increasing time in the order Li+> Na+> K+, and is due to an increased size of the cation for the chosen electrolytes. From the results, the conductivity values for 1-1 electrolytes in the membrane phase were found to be higher at the lower concentration for all the electrolytes in the order of Li+> Na+> K+. It was observed that the conductivity found to be increased with an increase of temperature and obeyed the Arrhenius equation. The activation energy increased with an increased concentration of electrolyte solution and the sequence for the energy of activation is Li+> Na+> K+. The Gibbs free energy, enthalpy and entropy for the ions were calculated at different concentrations and temperatures. All the values of ∆G, ∆H, and ∆S were found to be positive in nature and are following the order K+> Na+> Li+.