Solution of a model for the solventhyphen;electrolyte interactions in the mean spherical approximation

摘要

An electrolytic solution is simulated by a mixture of charged hard spheres and hard dipoles, all of the same size. This model can be solved exactly in the mean spherical approximation (MSA), yielding a set of three coupled high order algebraic equations for three unknowns, which are essentially the excess internal energies due to the charges alone, the dipoles alone, and the chargehyphen;dipole cross interaction. A rapidly converging series solution of these equations is proposed for the dilute solution regime. The first term in this series is the hardhyphen;core Debyehyphen;Huuml;ckel theory term, with electrostrictive corrections. We also obtain the leading term in the expansion for the infinite dilution limit of the ionhyphen;solvent excess chemical potential. Other relevant information could be obtained using standard formulas.