Towards Thermo-reversible Pickering Emulsions

Abstract

The stabilization of emulsions has been intensively studied and applied in e.g. food science. One method of stabilization is to cover the surface of droplets of oil in water by adsorbed colloidal particles in so-called Pickering emulsions. The stability of the emulsion is determined by the adsorption strength of the colloids, which is determined by the particle morphology, contact angle and the interfacial tension. This adsorption is usually irreversible and can usually be tuned by the size, shape and chemistry of the particle, now however, we propose a system with tunable interfacial tension. Therefore, we use binary mixtures with a closed-loop phase diagram and a thermally tunable interfacial tension, to obtain temperature-induced Pickering-like emulsions. A purpose-built heating set-up is designed to allow for a controllable uniform temperature. For two different binary mixtures, thermally tunable adsorption of colloids was obtained. Furthermore, at high temperatures a stable Pickering-like emulsion was induced. These temperature-induced Pickering-like emulsions are the first step towards thermo-reversible Pickering-like emulsions.