Ionic Liquids in Multiphase Systems

Ionic liquids (ILs) can be used to replace one or more phases in conventional oil/water emulsions including Pickering emulsions—surfactant-free emulsions which utilize nanoor micron-sized particles to stabilize the immiscible liquid-liquid interface. Due to the extreme tunability of both the ILs and particles used, the study of IL-based Pickering emulsions yields novel emulsion morphologies and insights into the ionic liquid-liquid-particle interactions present. This work discusses extensive experimental work on IL-based Pickering emulsions and IL/liquid interfaces, emphasizing unique phenomena—such as “bridging” between emulsion droplets and spontaneous particle transport across the interface—never observed in more conventional Pickering emulsions. Molecular dynamics (MD) simulations of particles at the IL/liquid interface are also discussed, and fundamental insights from these simulations are used to enhance understanding of the unique interface behavior revealed by experiment.