Monodisperse Aligned Emulsions from Demixing in Bulk Liquid Crystals

Abstract

We present recent findings on the formation of ordered emulsions from bulk demixing in liquid crystalline materials. In contrast to classical phase separations, which lead to randomly distributed macrodomains of various sizes, demixing in liquid crystals leads to remarkably uniform droplets that form ordered arrays. This distinctive behavior arises from the presence of topological defects and elastic distortions around the inclusions formed during the separation. These distortions induce long-range attractions and short-range repulsions. These forces direct the ordering of the microdomains and stabilize them against coalescence; limiting thereby the coarsening mechanism of the separation. We show that the ordering can be controlled on a large-scale by simply controlling the macroscopic alignment of the liquid crystal. We also discuss the influence of an external electric field and demonstrate marked differences with classical emulsions and colloids in isotropic fluids.