Buckling instability for a charged and fluctuating semiflexible polymer

TL;DR

This paper investigates how thermal fluctuations and electrostatic interactions influence the buckling instability of a charged semiflexible polymer under compression, revealing that temperature decreases the critical buckling force.

Contribution

It introduces a phase transition perspective to buckling instability and demonstrates the competing effects of electrostatic repulsion and thermal fluctuations through molecular dynamics simulations.

Findings

Critical buckling force decreases with increasing temperature.

Electrostatic interactions oppose thermal fluctuations, affecting buckling behavior.

Thermal fluctuations and electrostatics jointly determine the buckling threshold.

Abstract

In this article we address the problem of Euler's buckling instability in a charged semi-flexible polymer that is under the action of a compressive force. We consider this instability as a phase transition and investigate the role of thermal fluctuations in the buckling critical force. By performing molecular dynamic simulations, we show that the critical force decreases when the temperature increases. Repulsive electrostatic interaction in the finite temperature is in competition with thermal fluctuations to increase the buckling threshold.