The Physics of the Colloidal Glass Transition

TL;DR

This review discusses the current understanding of the colloidal glass transition, highlighting experimental techniques, key features like viscosity increase and dynamical heterogeneity, and comparisons to molecular glass transitions.

Contribution

It provides a comprehensive overview of experimental methods and recent developments in understanding the physics of colloidal glass transition.

Findings

Significant increase in viscosity and relaxation times near the transition

Observation of dynamical heterogeneity and aging phenomena

Comparison of colloidal and molecular glass transitions

Abstract

As one increases the concentration of a colloidal suspension, the system exhibits a dramatic increase in viscosity. Structurally, the system resembles a liquid, yet motions within the suspension are slow enough that it can be considered essentially frozen. This kinetic arrest is the colloidal glass transition. For several decades, colloids have served as a valuable model system for understanding the glass transition in molecular systems. The spatial and temporal scales involved allow these systems to be studied by a wide variety of experimental techniques. The focus of this review is the current state of understanding of the colloidal glass transition. A brief introduction is given to important experimental techniques used to study the glass transition in colloids. We describe features of colloidal systems near and in glassy states, including tremendous increases in viscosity and relaxation times, dynamical heterogeneity, and ageing, among others. We also compare and contrast the glass transition in colloids to that in molecular liquids. Other glassy systems are briefly discussed, as well as recently developed synthesis techniques that will keep these systems rich with interesting physics for years to come.