Effects of Dielectric Inhomogeneity and Electrostatic Correlation on the Solvation Energy of Ions in Liquids.

Abstract

Electrolytes often involve the spatially varying dielectric response of liquids and electrostatic correlation. Nevertheless, the complexity of their synergistic effects complicates our understanding of ion solvation and often limits theoretical approaches. Thus, we develop a Ginzburg-Landau-like (GL) theory that simultaneously considers these two features. We derive the modified Born solvation energy of ions, which accounts for the effect of saturated dipoles near the ions on the solvation energy, which is in good agreement with experimental data for different ionic charges and even for some selected liquid mixtures. Moreover, we consider the phase diagram of a mixture of polyelectrolyte and uncharged polymer and that of a mixture of ionic liquid and uncharged polymer. The GL theory encompasses the results of the previous mean-field theories, accounting for fluctuations of the electrostatic potentials and hence serves as a simple alternative approach to dielectrically inhomogeneous media.