Phase-Field Models for Particle-Stabilised Emulsions

TL;DR

This paper introduces a phase-field simulation framework for particle-stabilised emulsions, enabling large-scale, efficient modeling of complex formation processes like bijel development, and demonstrates its effectiveness through comparison with experimental results.

Contribution

The paper develops a novel phase-field model for simulating particle-stabilised emulsions, overcoming scale limitations of previous methods and capturing nanoparticle effects on emulsion morphology.

Findings

Higher nanoparticle concentrations reduce domain sizes in bijels.

The model accurately captures coupled phase separation and nanoparticle adsorption.

Results align with experimental observations of emulsion morphology.

Abstract

Particle-stabilised emulsions are a cornerstone of soft matter science due to their broad application and fundamental relevance. Computer simulations provide key insights into the formation and behaviour of these emulsions, yet current methods are limited by the spatiotemporal scales accessible for study. The principal issue is that particles are resolved individually. In this work, an alternative strategy is introduced based on phase-field theory, for which we establish the framework. By evolving continuous fields, large-scale dynamics can be simulated in a computationally efficient manner. Our approach is then applied to model the complex formation of a bicontinuous interfacially jammed emulsion gel (bijel) via solvent-transfer induced phase separation (STrIPS). By resolving the coupled dynamics of liquid phase separation and nanoparticle adsorption, the model allows for the characterisation of the influence of nanoparticles on the morphology. Higher concentrations of nanoparticles are found to reduce the average domain size of STrIPS bijels, in line with previous experimental evidence. The presented phase-field model thus represents a promising approach for the morphological investigation of complex particle-stabilised emulsions.