Pickering emulsions are formed when droplets are stabilized by the addition of colloidal particles, allowing the dispersion of one liquid in another, immiscible liquid. The result is a highly stable emulsion with applications including interfacial catalysis and surface-enhanced Raman spectroscopy (SERS). However, owing to the solid nature of the added particles, the accessible emulsion interface is limited.

In their ring-stabilized emulsions, around 80% of the oil–water interface was available, comparing very favourably with around 9% in a typical Pickering emulsion. “We were surprised that the Pickering emulsions (PEs) stabilized by the silica ring monolayers exhibited better stability than PEs stabilized by nanospheres when using the same mass of particles,” says Liu.