Bicontinuous particle-stabilized emulsion gels in magnetic fields: A Lattice Boltzmann simulation study*

Bicontinuous interfacially stabilized emulsion gels (bijels) are particle stabilized emulsions with a bicontinuous percolating domain morphology. They can serve as templates for the fabrication of functional porous materials with tailored microstructure, including membranes, catalyst supports, and drug delivery systems. Using Lattice Boltzmann simulations, we demonstrate how bijels stabilized by anisotropic magnetic particles respond to magnetic stimuli. The simulation results show that the domain size increases with the applied field strength. We investigate the interplay of orientational order of interface-embedded particles and the domain formation by analyzing the nematic order tensor. The results indicate that the domain structure becomes anisotropic which affects the permeability and tortuosity of the microstructure. We further investigate the stability of the bijel morphology and the relaxation behavior upon switching the magnetic field off. Preliminary results suggest that the formation rate differs from the relaxation rate, and the response to magnetic fields may exhibit hysteresis. We discuss the potential application of these effects in fabricating emulsion systems with tunable/switchable domain morphology.