Adsorption Transition of a Polyelectrolyte on a High-dielectric Charged Substrate

TL;DR

This paper investigates the adsorption transition of a polyelectrolyte on a high-dielectric charged substrate using simulations and analytical methods, revealing a first-order transition and a new scaling law for layer thickness.

Contribution

It provides a combined simulation and analytical study of polyelectrolyte adsorption, identifying the transition order and deriving a new layer thickness scaling law.

Findings

Adsorption transition is first-order at low ionic strength.

Surface monomer density linearly relates to surface charge density.

Derived and verified a new scaling law for layer thickness.

Abstract

The behavior of a polyelectrolyte adsorbed on a charged surface of high-dielectric constant is studied by both Monte-Carlo simulation and analytical methods. It is found that in a low ionic strength medium, the transition is first-order with the repulsive charged surface. The order parameter which characterize the polyelectrolyte adsorption, the surface monomer density, follows a linear relation with surface charge density. It indicates the polyelectrolyte is always compressed on the substrate. No conformation change exists before the de-sorption. Finally, a new scaling law for the layer thickness is derived and verified by the simulation data.