On the interaction of spherical double layers

Abstract

The mean spherical approximation of the primitive model of electrolyte solutions is analyzed for the case of two large, charged spherical ions separated by a distance r in a supporting medium of small ions of arbitrary size and concentration. It turns out that the case in which the radii of the small ions is zero (Debye–Hückel approximation) yields a simple analytic solution in agreement with the Verwey–Overbeek asymptotic results for this system. Simple analytic results are employed to illustrate the more general case.