Pickering emulsions with bare silica

Stabilization of o/w Pickering emulsions by fully hydrophilic fumed silica nanoparticles was successful upon selection of favorable oils. Silica particles were first dispersed in water as 100 nm aggregates, and stable o/w emulsions of 2–10 μm diameter were prepared using a standard rotor–stator device. The most relevant parameter allowing the selection of successful oils was the water–oil interfacial tension. The contact angle was difficult to manage with for predicting the stability because its measurement and its calculation were not accurate enough and the relevant differences were too small with that respect. The size of the stable emulsion was related to the silica content that fixed the interfacial area.