Stabilization of Emulsions by Particle Mixtures

Abstract

The wettability of colloidal particles at fluid interfaces has been thought to be one of the most important physicochemical factors in controlling the properties of Pickering emulsions. To obtain Pickering emulsions with desired properties using a unary particle requires chemical or physicochemical optimization of the particle surface, which can often be limiting or problematic for applied use. On the other hand, by mixing two types of particles, it is possible to achieve synergistic effects. For example, by adjusting the relative concentration of hydrophobic and hydrophilic particles, a transitional phase transition of emulsion can be induced. Some combinations of particles may, however, cause destabilization against coalescence or demulsification. This review proposes a classification of the stabilization of Pickering emulsions with mixtures of two types of particles, focusing on the wettability of the particles, and describes the stabilization or destabilization mechanisms reported so far.

graphical abstract