318: Life and death of far-from-equilibrium droplets and interfaces

Abstract: Emulsions are kinetically stabilized, but thermodynamically unstable, mixtures of immiscible fluids. Far-from-equilibrium emulsion droplets have been shown to exhibit fascinating active behaviors, such as motility, self-organization, and communication. It is fundamentally important to understand how materials self-organize or evolve under dissipative conditions in synthetic systems, such as chemically minimal colloids. I will present work aimed at understanding the non-equilibrium properties of emulsions and liquid interfaces, including droplet chemotactic motions, solubilization, and partitioning, which impact emergent physical phenomena. For example, partitioning is usually defined under equilibrium conditions, but solubilizing active droplets are far from equilibrium; such droplets persist for extended times but ultimately disappear due to droplet dissolution and micellar solubilization. Consequently, equilibrium properties like oil-water partition coefficients may not accurately describe properties of out-of-equilibrium droplets. We believe that the study of such active solubilizing droplets provides a means to both uncover a chemically-tunable platform for probing active matter but also contributes to fundamental understanding of how fluid phases and interfaces behave when far from equilibrium.