Non-diffusive dynamics in a colloidal glass: aging versus rejuvenation

TL;DR

This study investigates the microscopic dynamics of colloidal glasses, revealing non-diffusive behaviors and different aging or rejuvenation effects using X-ray photon correlation spectroscopy.

Contribution

It demonstrates how the dynamics of colloidal glasses depend on their history, showing distinct behaviors for aged and rejuvenated samples, and highlights the system's ability to transition between different dynamical states.

Findings

Different autocorrelation functions depending on sample history

Non-diffusive particle dynamics observed

Ability to switch between dynamical behaviors by adjusting parameters

Abstract

The microscopic dynamics of spontaneously aged and rejuvenated glassy Laponite is investigated through X-ray photon correlation spectroscopy. Two different behaviours of the intensity autocorrelation functions are observed depending on the history of the sample: stretched for spontaneously aged samples and samples rejuvenated from a Wigner glass and compressed, typical of anomalous dynamics, for samples rejuvenated from a DHOC glass. The relaxation time behaviour in the three cases indicates a non-diffusive dynamics of the particles. The present system offers therefore an overview of various dynamical behaviours previously observed individually in several systems and the possibility to pass from one to the other choosing ad hoc the time parameter.