Thermally activated processes in polymer dynamics

TL;DR

This study investigates thermally activated transitions in polymer energy landscapes through numerical simulations, comparing results with theoretical predictions, and explores the temperature range where the theory accurately describes polymer dynamics.

Contribution

It provides a detailed numerical analysis of escape times in polymer chains and evaluates the applicability of Langer's theoretical expression across different temperature regimes.

Findings

Dynamics within the native valley are well described by thermally activated processes at moderate temperatures.

Deviations from Langer's theory occur at higher temperatures, indicating limitations of the theoretical model.

The study discusses potential reasons for discrepancies between simulations and theory.

Abstract

Jumps between neighboring minima in the energy landscape of both homopolymeric and heteropolymeric chains are numerically investigated by determining the average escape time from different valleys. The numerical results are compared to the theoretical expression derived by Langer [J.S. Langer, Ann. Phys. 54 (1969) 258] with reference to a 2N-dimensional space. Our simulations indicate that the dynamics within the native valley is well described by a sequence of thermally activated process up to temperatures well above the folding temperature. At larger temperatures, systematic deviations from the Langer's estimate are instead observed. Several sources for such discrepancies are thoroughly discussed.