The effect of confinement on the interaction between two like-charged rods

TL;DR

This study uses Monte Carlo simulations to explore how confinement and ionic size influence the electrostatic interactions between like-charged rods in an electrolyte, revealing conditions for attraction and repulsion.

Contribution

It demonstrates that confinement and ionic size can switch the sign of rod-rod interactions in monovalent electrolytes, offering a new self-assembling mechanism insight.

Findings

Attraction and repulsion between rods depend on confinement and ionic size.

A simple self-assembling mechanism is proposed for DNA-lipid interactions.

Interaction sign can switch in monovalent electrolytes based on conditions.

Abstract

Monte Carlo simulations were employed to study two charged rods confined between two unlike charged plates, all immersed in a model electrolyte. Recently, it was shown that two rods immersed in a multivalent counterion solution may show attraction (PRL 78, 2477 (1997)). Here we show for a monovalent electrolyte that rod-rod attraction and repulsion can switch sign depending on confinement and ionic size. We also propose a simple self-assembling mechanism which may be helpful to understand the DNA-lipid bilayers complexation.