Structural Response of Bijels Stabilized by Ellipsoidal Magnetic Particles

Abstract

Bicontinuous interfacially jammed emulsion gels (bijels) are soft materials characterized by an interconnected network of fluid domains stabilized by colloidal particles. Their tunable microstructures make them promising candidates for applications in material templating, membrane separations, and drug delivery. In this study, we explore how magnetic fields influence the post-formation structural evolution of bijels stabilized by magnetically responsive ellipsoidal particles. Using hybrid Lattice Boltzmann–Molecular Dynamics simulations, we examine the response of systems stabilized by oblate and prolate particles across a range of magnetic field strengths (¯B = 0, 0.2, 0.5, 1). We quantify structural evolution through metrics including domain size, average interfacial tilt angle and six-fold Steinhardt bond orientational order. Our findings reveal that particle shape mediates the extent of anisotropy and domain coarsening, with prolate particles promoting ordering and alignment, while oblate particles tend to disrupt local structure. Finally, we compare bijels formed under an applied field to those exposed post-formation, showing that magnetic alignment can effectively tune microstructure in both cases to an approximately equal degree, highlighting a viable route for post-processing control of responsive bijel materials.