Spontaneous Formation of Stable Capillary Bridges for Firming Compact Colloidal Microstructures in Phase Separating Liquids: A Computational Study

TL;DR

This computational study demonstrates how capillary bridges spontaneously form and stabilize between colloidal particles during phase separation, enabling in-situ firming of fragile microstructures through a self-stabilization mechanism.

Contribution

It reveals a novel self-stabilization mechanism for capillary bridges in phase separating liquids, contrasting with traditional coarsening, and discusses their role in microstructure stability.

Findings

Capillary bridges form spontaneously during phase separation.

Self-stabilization maintains microstructure integrity.

Potential for in-situ firming of colloidal structures.

Abstract

Computer modeling and simulations are performed to investigate capillary bridges spontaneously formed between closely packed colloidal particles in phase separating liquids. The simulations reveal a self-stabilization mechanism that operates through diffusive equilibrium of two-phase liquid morphologies. Such mechanism renders desired microstructural stability and uniformity to the capillary bridges that are spontaneously formed during liquid solution phase separation. This self-stabilization behavior is in contrast to conventional coarsening processes during phase separation. The volume fraction limit of the separated liquid phases as well as the adhesion strength and thermodynamic stability of the capillary bridges are discussed. Capillary bridge formations in various compact colloid assemblies are considered. The study sheds light on a promising route to in-situ (in-liquid) firming of fragile colloidal crystals and other compact colloidal microstructures via capillary bridges.