Invariance of Structure in an Aging Colloidal Glass

TL;DR

This study investigates the structural invariance of aging colloidal glasses, revealing that while dynamics change with age, the local tetrahedral packing geometry remains constant, highlighting a decoupling of structure and dynamics.

Contribution

It demonstrates that the local tetrahedral structure in colloidal glasses does not evolve during aging, despite changes in the system's dynamics.

Findings

Aging affects the dynamics of colloidal glasses

Local tetrahedral geometry remains unchanged with age

Structural invariants persist despite dynamic evolution

Abstract

We study concentrated colloidal suspensions, a model system which has a glass transition. The non-equilibrium nature of the glassy state is most clearly highlighted by aging -- the dependence of the system's properties on the time elapsed since vitrification. Fast laser scanning confocal microscopy allows us to image a colloidal glass and track the particles in three dimensions. We analyze the static structure in terms of tetrahedral packing. We find that while the aging of the suspension clearly affects its dynamics, none of the geometrical quantities associated with tetrahedra change with age.