Understanding Particle Wettability in Light-Responsive Pickering Emulsions

This work aims to understand the mode-of-action of an emergent class of stimuli-responsive materials – Light-responsive Pickering emulsions. These are mixtures of oil and water where one phase is dispersed as droplets throughout the bulk phase and the droplet boundary is stabilised by light-responsive solid particles. When light of one wavelength is shone on the particles, the droplets destabilise, releasing their contents. The emulsion reforms on irradiation with light of a different colour and the destabilisation/stabilisation process can be repeated over multiple cycles. This can be exploited for the delivery of drugs in the body, the separation of oil from water and the recovery of catalysts in industrial reactions. The mechanism for this stabilisation/destabilisation process, however, is not well understood. Using small angle neutron scattering, we aim to investigate how the particle structure affects how how they pack at the oil-water boundary and how this is changed in response to light. This will allow us to tune the properties of the emulsions to better suit the varied requirements of the above applications.