Electrochemical characterization of membranes

Abstract

The determination of electrochemical characteristics of membranes on the basis of membrane potential measurements and electrochemical impedance studies has been described. Cellulose acetate membrane has been used alongwith sodium chloride and magnesium chloride solutions to investigate variation of transport number, pennselectivity and fixed charge density with concentration and <em>p</em>H. Alteration in these membrane characteristics in the presence of lecithin has also been investigated. Dependence of impedance of Dowex-50 membrane with frequency has been studied over a .wide range using solution of sodium chloride with and without cholesterol with the object of estimation of membrane conductance and capacitance; and to examine their variation with surfactant concentration. The results indicate progressive accumulation of surfactant molecules in the membrane solution interfacial region which is significantly altered with the electrical potential to which the membrane is subjected.