The role of internal chain dynamics on the rupture kinetics of adhesive contacts

TL;DR

This paper investigates how internal chain dynamics influence the rupture behavior of non-covalent adhesive contacts in polymer chains, revealing different rupture regimes and the impact of contact positioning on rupture kinetics.

Contribution

It introduces a model linking internal Rouse modes to rupture kinetics, highlighting the effects of contact location and force magnitude on rupture behavior.

Findings

Reversible rupture occurs below critical force, coupled with internal modes.

Contact lifetime distributions follow a double-exponential (Gumbel) distribution.

Proximity of contacts influences cooperative rupture and stress distribution.

Abstract

We study the forced rupture of adhesive contacts between monomers that are not covalently linked in a Rouse chain. When the applied force ($f$) to the chain end is less than the critical force for rupture ($f_c$), the {\it reversible} rupture process is coupled to the internal Rouse modes. If $f/f_{c}$$>$1 the rupture is {\it irreversible}. In both limits, the non-exponential distribution of contact lifetimes, which depends sensitively on the location of the contact, follows the double-exponential (Gumbel) distribution. When two contacts are well separated along the chain, the rate limiting step in the {\it sequential} rupture kinetics is the disruption of the contact that is in the chain interior. If the two contacts are close to each other, they cooperate to sustain the stress, which results in an ``all-or-none'' transition.