Electrochemical characterization and assessment of performance of zirconium phosphate and zinc modified zirconium phosphate membranes in aqueous sodium chloride solutions

Prepared membranes, zinc-zirconium phosphate (M-1 and M-2) and zirconium phosphate (M-3) were electrochemically characterized by membrane potential and membrane conductance measurements using aqueous sodium chloride solution of varying compositions. The data have been used for the estimation of transport number of ions and solvent in the membrane phase in addition to permselectivity and membrane fixed charge density. Membrane conductance data were used to estimate the ionic permeability and verify diffusion controlled criteria endowed with the membrane phase. Solute and co-ion permeabilities were compared and found that their values were comparable. Solute rejection of membranes was examined for limiting and intermediate cases of solute–solvent interaction in the membrane phase along with positional solute rejection. Zirconium phosphate membrane showed considerable polarization index deviation from unity indicates its minor perspective than zinc-zirconium phosphate membrane. Results show that zinc modified zirconium phosphate membranes reflected modified elastic properties than zirconium phosphate membrane. The well-known Teorell–Meyer–Sievers (TMS) theory, which describes the membrane potential for charged membranes, was considered as a frame work.