A model for cage formation in colloidal suspension of laponite

TL;DR

This paper models the glass transition in laponite colloidal suspensions, proposing that cluster swelling and space filling lead to dynamic slowdown and vitrification, aligning with mode coupling theory predictions.

Contribution

It introduces a new model linking cluster swelling to glass transition in laponite suspensions, supported by mode coupling theory.

Findings

Cluster swelling correlates with increased viscosity.

Model accurately predicts glass transition features.

Mode coupling theory aligns with experimental observations.

Abstract

In this paper we investigate glass transition in aqueous suspension of synthetic hectorite clay, laponite. We believe that upon dispersing laponite clay in water, system comprises of clusters (agglomerates) of laponite dispersed in the same. Subsequent osmotic swelling of these clusters leads to increase in their volume fraction. We propose that this phenomenon is responsible for slowing down of the overall dynamics of the system. As clusters fill up the space, system undergoes glass transition. Along with the mode coupling theory, proposed mechanism rightly captures various characteristic features of the system in the ergodic regime as it approaches glass transition.