UCLA

Oil-in-water nanoemulsions are aqueous dispersions of oil droplets having radii a < 100 nm and serve as interesting model systems for studying basic colloidal science. The nature of such small droplet sizes gives rise to a new range of physical properties that are potentially beneficial to a wide range of industries. In this dissertation, methods of controlling droplet sizes and morphologies through manipulation of dispersed-phase components are presented. An evaporative ripening technique is developed in which one of the components in a multi-component dispersed-phase nanoemulsion is evaporated out of the system to create nanoemulsion droplet sizes approaching the micellar scale. Foundational groundwork is then provided for cryogenic transmission electron microscopy (CTEM) of oil-in-water nanoemulsions; expansion of water upon freezing may cause nanoinclusions to appear in nanoemulsion droplets depending on the phase of ice and oil type. Finally, a method of controlling coalescence using oppositely charged surfactants is presented and extended to produce anisotropic emulsions and nanoemulsions using multiple immiscible liquids.