Shear-driven solidification of dilute colloidal suspensions

TL;DR

This paper explains how shear flow causes dilute colloidal suspensions to solidify through cluster formation and interconnection, blending concepts from gelation and jamming.

Contribution

It reveals the mechanism of shear-induced solidification involving cluster dynamics and bond formation, unifying gelation and jamming phenomena.

Findings

Shear induces formation and breakage of large colloidal clusters.

Cluster density increases with shearing time.

Solidification occurs via interconnection of clusters into a rigid network.

Abstract

We show that the shear-induced solidification of dilute charge-stabilized (DLVO) colloids is due to the interplay between the shear-induced formation and breakage of large non-Brownian clusters. While their size is limited by breakage, their number density increases with the shearing-time. Upon flow cessation, the dense packing of clusters interconnects into a rigid state by means of grainy bonds, each involving a large number of primary colloidal bonds. The emerging picture of shear-driven solidification in dilute colloidal suspensions combines the gelation of Brownian systems with the jamming of athermal systems.