Thermally Activated Asymmetric Structural Recovery in a Soft Glassy Nano-Clay Suspension

TL;DR

This study investigates the structural recovery of a soft glassy Laponite suspension, revealing that temperature influences the recovery rate under constant conditions but affects the recovery path during temperature jumps, due to counterion mobility constraints.

Contribution

It demonstrates the asymmetric structural recovery behavior in soft glassy suspensions during temperature changes, highlighting the role of counterion mobility restrictions.

Findings

Recovery rate depends on temperature during isothermal conditions.

Recovery path is affected by temperature jumps and direction of change.

Counterion mobility constraints influence structural recovery dynamics.

Abstract

In this work we study structural recovery of a soft glassy Laponite suspension by monitoring temporal evolution of elastic modulus under isothermal conditions as well as following step temperature jumps. Interestingly, evolution behavior under isothermal conditions indicates the rate, and not the path of structural recovery, to be dependent on temperature. The experiments carried out under temperature jump conditions however trace a different path of structural recovery, which shows strong dependence on temperature and the direction of change. Further investigation of the system suggests that this behavior can be attributed to restricted mobility of counterions associated with Laponite particle at the time of temperature change, which do not allow counterion concentration to reach equilibrium value associated with the changed temperature. Interestingly this effect is observed to be comparable with other glassy molecular and soft materials, which while evolve in a self-similar fashion under isothermal conditions, show asymmetric behavior upon temperature change.