Investigation of the stability in emulsions stabilized with different surface modified titanium dioxides

Today micronised titanium dioxide is widely used in cosmetic sunscreen emulsions due to its broad UV-absorption spectrum and its high aesthetical acceptance. In addition to its UV-absorption capacity, titanium dioxide can also be used as a stabilizing agent for pickering-emulsions [J. Chem. Soc. Trans. 91 (2001) 1907]. In the present work studies were performed in order to determine the effect of different surface modified titanium dioxides on the type and the stability of surfactant-free emulsions. The investigated emulsions contain nanometer-sized titanium dioxide particles, medium chain triglycerides and water as their main components. Present results indicate that stable pickering-emulsions can be formed using nanometer-sized titanium dioxides. The type and stability of the prepared emulsions depend on the wettability of the stabilizing TiO2 nanoparticles. Particle wettability is influenced by the type, the amount, and the combination of the used inorganic and organic materials used for the surface modification of TiO2. (C) 2003 Elsevier B.V. All rights reserved.