Dynamics of ion atmosphere relaxation around a newly created dipolar solute

Abstract

A theoretical study of ion atmosphere relaxation around a newly created dipolar solute in electrolyte solutions is presented. A microscopic expression of the time dependent interaction energy of a dipolar solute with its surrounding solution ions is derived within linear response theory. The presence of strong interionic correlations is included through ionic structure factors. The theory also includes the diffusive and non-diffusive modes of relaxation through frequency dependent diffusion coefficients. It is found that the relaxation of ion atmosphere is governed mainly by diffusional motion of the solution ions. The rate of relaxation depends rather strongly on ion concentration, the dielectric constant of the medium and also on the size of the dipolar solute. Some applications of the present study are also discussed.