Pickering Emulsions

Pickering or particle-stabilised emulsions are mixtures of two incompatible liquid phases where the interface between is stabilised by solid particles. They are found naturally occurring in food products such as milk or mayonnaise and as additives in cosmetics and pharmaceuticals. They offer greater stability than conventional emulsifiers (i.e. surfactants) and are generally less harmful to the environment, with the option to use natural stabilisers such as cellulose or chitin particles. 

A schematic representation of a Pickering emulsion droplet of diameter, D. Figure courtesy of Kieran Richards.,

A key focus area of our group is the characterisation of Pickering emulsions, with the aim of better understanding the factors that affect droplet size and morphology. Moreover, we are interested in investigating stimuli-responsive Pickering emulsions and the effect of a given stimuli on droplet morphology. Such properties are important as they control factors such as droplet loading, rheology and optical opacity.

An optical microscopy image showing Pickering emulsion droplets identified using computer vision. 

In order to characterise our emulsions we have developed techniques that combine optical microscopy and computer-vision methods to precisely measure the size and distribution of droplets. This technique is more affordable that the equivalent laser diffraction methods and can be used with samples of poor stability or where the volume is limited.