Oil-in-Oil Pickering emulsions stabilized with kaolinite

Oil-oil Pickering emulsions are remarkable systems in pharmaceutical and cosmetic sciences, minimizing oxidation and hydrolysis reactions. Versatile and environmentally friendly clay minerals are poorly discussed in literature as stabilizing particles in these unconventional oil-oil emulsions. We investigated the effect of kaolinite applied in a castor oil/silicone oil emulsion at different oil fractions and kaolinite concentrations. Samples without kaolinite showed a limited and low stability self-emulsification. According to the particle concentration increase, emulsions presented higher emulsified volumes and lower droplet diameter, from 100 to 20 & mu;m. Microscopic images revealed Pickering emulsions, where cage effect started to be observed at 2 wt% kaolinite. Castor oil and silicone oil behaves like liquids, however, in the presence of kaolinite the emulsions formed changed to a solid viscoelastic system, improving long-term stability.

Automated summary

The effect of kaolinite on a castor oil/silicone oil emulsion was investigated. The introduction of kaolinite transformed the emulsion from a liquid to a solid viscoelastic system, improving long-term stability.