Glassy dynamics and dynamical heterogeneity in colloids

TL;DR

This paper reviews the phenomena of glass transition in concentrated colloidal suspensions, highlighting the spatial and temporal heterogeneity in dynamics observed near the transition, using optical techniques on particles 100-1000 nm in size.

Contribution

It provides a comprehensive overview of experimental observations of dynamical heterogeneity in colloidal glasses, emphasizing optical methods and various interaction types.

Findings

Observation of spatial heterogeneity in particle dynamics

Detection of temporal fluctuations near the glass transition

Comparison of hard-sphere and other colloidal interactions

Abstract

Concentrated colloidal suspensions are a well-tested model system which has a glass transition. Colloids are suspensions of small solid particles in a liquid, and exhibit glassy behavior when the particle concentration is high; the particles are roughly analogous to individual molecules in a traditional glass. Because the particle size can be large (100 nm - 1000 nm), these samples can be studied with a variety of optical techniques including microscopy and dynamic light scattering. Here we review the phenomena associated with the colloidal glass transition, and in particular discuss observations of spatial and temporally heterogeneous dynamics within colloidal samples near the glass transition. Although this Chapter focuses primarily on results from hard-sphere-like colloidal particles, we also discuss other colloidal systems with attractive or soft repulsive interactions.