Ion-pairing in aqueous media. An exact solution for the interaction energy associated with two dielectric spheres

Abstract

The phenomenon of ion-pairing in strong aqueous electrolyte solutions is examined by looking at the Coulomb interactions between two typical ions. These are modelled as hard-spheres in order to take account of the short-range forces between them and the surroundings are treated as a continuum having a macroscopic value for the dielectric constant of pure water.

The present work leads to exact analytical formulae for the field strength and effective dielectric constant of the system. Only approximate and purely numerical solutions have been previously available and these are compared with the full solutions.