Emulsion Stabilization with Talc Microparticles

Abstract

Oil-in-water and water-in-oil stable emulsions have been obtained depending on the type of an oil (saturated hydrocarbon or olive oil) with the use of talc microparticles. This is explained by the inhomogeneity of talc microparticle surface, which has basal hydrophobic and lateral hydrophilic faces. The amphiphilic components of olive oil can be adsorbed on the lateral faces of the particles, thereby making them completely hydrophobic. In the case of saturated hydrocarbons (hexane and octane) the type of emulsion is predetermined by oil volume fraction Ø_O in a liquid phase and the order of wetting talc particles by water and oil. As the oil fraction is increased or decreased, inversion of the phases is observed at Ø_O = 0.54–0.60. In the range of Ø_O values from 0.54 to 0.60, the emulsion is coarse and unstable. The optimal concentration of talc microparticles, at which stable emulsions with an average droplet diameter of 150 μm are formed, is 8.8–21.5 g/100 mL of a liquid phase.