To make a glass - avoid the crystal

TL;DR

This paper reviews strategies to prevent crystallization in colloidal suspensions and introduces a new method to form amorphous colloidal solids at low concentrations using highly charged spheres.

Contribution

It presents a novel approach to create colloidal glasses at low volume fractions with highly charged spheres, expanding the understanding of amorphous solid formation.

Findings

Successful formation of amorphous colloidal solids at low salt and volume fractions.

Introduction of a new method using highly charged spheres to avoid crystallization.

Comparison of experimental strategies based on topological, thermodynamic, and kinetic considerations.

Abstract

Colloidal model systems allow for a flexible tuning of particle sizes, particle spacings and mutual interactions at constant temperature. Colloidal suspensions typically crystallize as soon as the interactions get sufficiently strong and long-ranged. Several strategies have been successfully applied to avoid crystallization and instead produce colloidal glasses. Most of these amorphous solids are formed at high particle concentrations. This paper shortly reviews experimental attempts to produce amorphous colloidal solids using strategies based on topological, thermodynamic and kinetic considerations. We complement this overview by introducing a (transient) amorphous solid forming in a thoroughly deionized aqueous suspension of highly charged spheres at low salt concentration and very low volume fractions.