Dipolar Capillary Interactions between Tilted Ellipsoidal Particles Adsorbed at Fluid-Fluid Interfaces

TL;DR

This study numerically investigates dipolar capillary interactions between tilted ellipsoidal particles at fluid interfaces, revealing energy barriers and stable configurations that influence particle assembly and emulsion properties.

Contribution

It provides detailed numerical analysis of how particle shape, tilt, and separation affect capillary interactions and resulting assembly structures.

Findings

Energy barrier exists between tip-tip and side-side configurations.

Side-side configuration is the global energy minimum.

Clusters form symmetric flower-like and ring-like arrangements.

Abstract

Capillary interactions have emerged as a tool for the directed assembly of particles adsorbed at fluid-fluid interfaces, and play a role in controlling the mechanical properties of emulsions and foams. In this paper, following Davies et al. [Advanced Materials, 26, 6715 (2014)] investigation into the assembly of ellipsoidal particles at interfaces interacting via dipolar capillary interactions, we numerically investigate the interaction between tilted ellipsoidal particles adsorbed at a fluid-fluid interface as their aspect ratio, tilt angle, bond angle, and separation vary. High-resolution Surface Evolver simulations of ellipsoidal particle pairs in contact reveal an energy barrier between a metastable tip-tip configuration and a stable side-side configuration. The side-side configuration is the global energy minimum for all parameters we investigated. Lattice Boltzmann simulations of clusters of up to 12 ellipsoidal particles show novel highly symmetric flower-like and ring-like arrangements.