Electrolytic conductivity of multicomponent polyelectrolyte solutions

Abstract

The electrolytic conductivity of polyelectrolytes in the presence of simple salt has been investigated. To interprete the conductivity behaviour of multicomponent solutions a general conductivity theory, based on non-equilibrium thermodynamics, has been developed. According to the theory the total frictional interaction of ions can be separated into two effects, characterising friction between the ions and the solvent and interionic friction. The latter effect is cooperative and common to all ions. As the interionic friction effect is different in simple salt and polyelectrolyte solutions, non-additivity of conductivities is expected when electrolytes of the two kinds are mixed. Experiments carried out with polyelectrolytes of varying charge densities clearly displayed the non-additive character of conductivity, the effect being pronounced in very dilute solutions.