Effect of dielectric discontinuity on a spherical polyelectrolyte brush

TL;DR

This study uses molecular dynamics simulations to investigate how dielectric discontinuity affects spherical polyelectrolyte brushes and counterions, revealing insights into their structural and osmotic properties.

Contribution

It introduces a simulation approach that accounts for dielectric discontinuity via image charges, providing new insights into polyelectrolyte brush behavior.

Findings

Counterion density profiles vary with nanoparticle radius and charge

Mean-field theory approximates osmotic properties effectively

Dielectric discontinuity significantly influences brush structure

Abstract

In this paper we perform molecular dynamics simulations of a spherical polyelectrolyte brush and counterions in a salt-free medium. The dielectric discontinuity on the grafted nanoparticle surface is taken into account by the method of image charges. Properties of the polyelectrolyte brush are obtained for different parameters, including valency of the counterions, radius of the nanoparticle, and the brush total charge. The monovalent counterions density profiles are obtained and compared with a simple mean-field theoretical approach. The theory allows us to obtain osmotic properties of the system.