Activated bond-breaking processes preempt the observation of a sharp glass-glass transition in dense short-ranged attractive colloids

TL;DR

This study uses molecular dynamics simulations to investigate the dynamics of dense short-ranged attractive colloids, revealing that bond-breaking processes prevent the clear observation of a predicted sharp glass-glass transition.

Contribution

It demonstrates that activated bond-breaking processes destabilize the attractive glass, challenging the ideal Mode Coupling Theory's prediction of a sharp glass-glass transition.

Findings

Attractive glass is unstable due to bond-breaking.

Bond-breaking converts attractive glass into hard-sphere glass.

Preemption of the sharp glass-glass transition observed.

Abstract

We study -- using molecular dynamics simulations -- the temperature dependence of the dynamics in a dense short-ranged attractive colloidal glass to find evidence of the kinetic glass-glass transition predicted by the ideal Mode Coupling Theory. According to the theory, the two distinct glasses are stabilized one by excluded volume and the other by short-ranged attractive interactions. By studying the density autocorrelation functions, we discover that the short-ranged attractive glass is unstable. Indeed, activated bond-breaking processes slowly convert the attractive glass into the hard-sphere one, preempting the observation of a sharp glass-glass transition.