Viscosity of water-oil emulsions with added nano-size particles

The viscosity of emulsion and suspensions in the presence of two types of nano-size panicles that, have different affinity for oil, have been investigated. It has been found out that both oil-solid suspensions and oil-water-solid mixtures behave as pseudoplastic fluids at all studied solid concentrations. The viscosity of emulsion-solid mixtures does not seem to get affected by water concentration, yet it is a function of solid concentration. The ability of solids to act as emulsifying agents has also been investigated. It has been established that neither of the two types of solids used is capable of stabilizing water-in-oil or oil-in-water emulsions in the absence of surfactants. At low concentrations of solids and in the presence of an oil-soluble surfactant, both oil-wet and water-wet solids, however, are capable of stabilizing waterin-oil emulsions. In the presence of water-soluble surfactant, only water-wet solids are capable of stabilizing oil-in-water emulsions.