Electrostatic interactions mediated by polarizable counterions: weak and strong coupling limits

TL;DR

This paper explores how polarizable counterions influence electrostatic interactions in Coulomb fluids, deriving weak and strong coupling approximations to analyze density profiles and pressures in dielectric systems.

Contribution

It introduces the derivation of weak- and strong-coupling approximations for polarizable counterions in inhomogeneous Coulomb fluids, highlighting their impact on electrostatic interactions.

Findings

Polarizability significantly alters counterion density distributions.

Electrostatic interactions are affected by counterion polarizability.

Differences observed compared to non-polarizable counterions.

Abstract

We investigate the statistical mechanics of an inhomogeneous Coulomb fluid composed of charged particles with static polarizability. We derive the weak- and the strong-coupling approximations and evaluate the partition function in a planar dielectric slab geometry with charged boundaries. We investigate the density profiles and the disjoining pressure for both approximations. Comparison to the case of non-polarizable counterions shows that polarizability brings important differences in the counterion density distribution as well as the counterion mediated electrostatic interactions between charged dielectric interfaces.