Transient Binding and Dissipation in Semi-flexible Polymer Networks

TL;DR

This paper investigates how transient cross-links in semi-flexible polymer networks contribute to local stress relaxation and energy dissipation, combining experimental tuning of cross-linker off-rate with a microscopic unbinding model to explain the frequency response.

Contribution

It introduces a combined experimental and theoretical approach to quantify how transient cross-link dynamics affect the mechanical behavior of polymer networks.

Findings

Transient cross-links enable local stress relaxation.

Energy dissipation occurs predominantly in an intermediate frequency regime.

Theoretical model accurately reproduces experimental frequency response.

Abstract

While polymer solutions lack the mechanical stability only transiently cross-linked networks can fulfill the competing requirements of structural stability and maximal energy dissipation. Here, we show that transient cross-links entail local stress relaxation and energy dissipation in an intermediate elasticity dominated frequency regime. We quantify the mechanical response of a semi-flexible polymer network by experimentally tuning the off-rate of the transient cross-linker molecule and theoretically reproduce the measured frequency response by a model that is predicated on microscopic unbinding events.