Polyelectrolyte Bundles

TL;DR

This study uses Molecular Dynamics simulations to explore the stability and size of polyelectrolyte bundles with hydrophobic side chains, revealing conditions for stable finite bundle sizes and implications for DNA aggregation.

Contribution

The paper introduces a detailed simulation-based analysis of polyelectrolyte bundle stability, highlighting the effects of hydrophobicity, electrostatic strength, and oligomer length on bundle size.

Findings

Stable finite bundle size for PPP-like parameters.

Influence of oligomer length on bundle stability.

Similarity to DNA condensation phenomena.

Abstract

Using extensive Molecular Dynamics simulations we study the behavior of polyelectrolytes with hydrophobic side chains, which are known to form cylindrical micelles in aqueous solution. We investigate the stability of such bundles with respect to hydrophobicity, the strength of the electrostatic interaction, and the bundle size. We show that for the parameter range relevant for sulfonated poly-para-phenylenes (PPP) one finds a stable finite bundle size. In a more generic model we also show the influence of the length of the precursor oligomer on the stability of the bundles. We also point out that our model has close similarities to DNA solutions with added condensing agents, hinting to the possibility that the size of DNA aggregates is under certain circumstances thermodynamically limited.