Detachment Energies of Spheroidal Particles from Fluid-Fluid Interfaces

TL;DR

This paper introduces a simplified model for calculating the detachment energy of spheroidal particles from fluid-fluid interfaces, validated by lattice Boltzmann simulations, aiding the design of emulsions and related materials.

Contribution

A new detachment energy model for spheroids that depends only on aspect ratio and center of mass height, validated through simulations.

Findings

Model accurately predicts detachment energies for spheroids.

Simulation results support the model's applicability to emulsions.

Experimental implications for designing particle-stabilized systems.

Abstract

The energy required to detach a single particle from a fluid-fluid interface is an important parameter for designing certain soft materials, for example, emulsions stabilised by colloidal particles, colloidosomes designed for targeted drug delivery, and bio-sensors composed of magnetic particles adsorbed at interfaces. For a fixed particle volume, prolate and oblate spheroids attach more strongly to interfaces because they have larger particle-interface areas. Calculating the detachment energy of spheroids necessitates the difficult measurement of particle-liquid surface tensions, in contrast with spheres, where the contact angle suffices. We develop a simplified detachment energy model for spheroids which depends only on the particle aspect ratio and the height of the particle centre of mass above the fluid-fluid interface. We use lattice Boltzmann simulations to validate the model and provide quantitative evidence that the approach can be applied to simulate particle-stabilized emulsions, and highlight the experimental implications of this validation.