Colloidal gels assembled via a temporary interfacial scaffold

TL;DR

This paper demonstrates a novel colloidal gel formed via a temporary interfacial scaffold that remains stable after remixing liquids, with a structure maintained by DLVO bonding and simulation-supported stabilization mechanisms.

Contribution

It introduces a new type of colloidal gel stabilized by a temporary interfacial scaffold and provides experimental and simulation evidence for its stability mechanisms.

Findings

Stable colloidal gels can be formed via interfacial scaffolds.

The gel structure is maintained by primary-minimum DLVO bonding.

Simulation shows short-range attraction and repulsive barriers stabilize the gel.

Abstract

The liquid-liquid phase separation of a binary solvent can be arrested by colloidal particles trapped at the interface [K. Stratford et al., Science 309, 5744 (2005)]. We show experimentally that the colloidal network so formed can remain stable after fully remixing the liquids, creating a new type of gel in which colloids in a single-phase solvent have locally planar coordination. We argue that this structure is likely maintained by primary-minimum DLVO bonding of our charged colloids, created under strong compression by capillary forces. We present simulation evidence that the combination of a short-ranged attraction with a repulsive barrier can strongly stabilize such locally planar gels.