Stress Relaxation in Aging Soft Colloidal Glasses

TL;DR

This study examines how aging soft colloidal glasses relax stress after step strains, revealing that larger strains significantly slow relaxation and suggest the system explores deeper energy states.

Contribution

It provides new insights into the strain-dependent relaxation dynamics and energy landscape exploration in aging colloidal glasses.

Findings

Slow relaxation times increase with strain amplitude.

Stress relaxation exhibits a two-step decay.

Deeper energy landscape exploration occurs with larger strains.

Abstract

We investigate the stress relaxation behavior on the application of step strains to aging aqueous suspensions of the synthetic clay Laponite. The stress exhibits a two-step decay, from which the slow relaxation modes are extracted as functions of the sample ages and applied step strain deformations. Interestingly, the slow time scales that we estimate show a dramatic enhancement with increasing strain amplitudes. We argue that the system ends up exploring the deeper sections of its energy landscape following the application of the step strain.