Thermodynamic properties and phase equilibria of charged hard sphere chain model for polyelectrolyte solutions

Abstract

A recent thermodynamic perturbation theory for flexible polyelectrolyte solutions is extended to study thermodynamic properties and phase equilibria for polyelectrolyte solutions with different polyion, chain lengths. Osmotic pressure, activity coefficient of an individual ion (polyion or counterion) and average activity coefficient are calculated. Except for the activity coefficient of the polyion, the chain length dependence of the properties is small. Also presented are vapour-liquid equilibrium coexisting curves, vapour pressures and critical points. As the polyion chain length approaches infinity the critical properties (temperature, pressure and density) become constants.