Polyelectrolyte Multilayering on a Charged Sphere

TL;DR

This study uses Monte Carlo simulations to explore polyelectrolyte multilayer formation on charged spheres, revealing that pure electrostatics do not support multilayering at equilibrium, but short-range attractions can stabilize multilayers.

Contribution

It demonstrates that multilayering on charged spheres is not feasible through electrostatics alone at equilibrium, highlighting the role of non-electrostatic interactions.

Findings

Multilayering is unlikely with purely electrostatic interactions.

Short-range attractions can stabilize multilayer structures.

Electroneutrality is maintained at each layer deposition.

Abstract

The adsorption of highly \textit{oppositely} charged flexible polyelectrolytes onto a charged spherical surface is investigated by means of Monte Carlo simulations in a fashion which resembles the layer-by-layer deposition technique introduced by Decher. Electroneutrality is insured at each step by the presence of monovalent counterions (anions and cations). We study in detail the structure of the \textit{equilibrium} complex. Our investigations of the first few layer formations strongly suggest that multilayering in spherical geometry is not possible as an equilibrium process with purely electrostatic interactions. We especially focus on the influence of specific (non-electrostatic) short range attractive interactions (e.g., Van der Waals) on the stability of the multilayers.