Study on the stability of water-in-kerosene nano-emulsions and their dynamic surface properties

In this work, formations of water-in-kerosene nano-emulsions using water/mixed nonionic surfactant/kerosene system has been studied. The high energy emulsification method was used to form four emulsions using different water contents: 5, 7, 10 and 14% (v/v). These nano-emulsions were stabilized with emulsifiers having different hydrophilic lipophilic balance (HLB) namely; sorbitan monooleate (HLB = 4.3), ethoxylated (20 EO) sorbitan trioleate (HLB = 11) and a mixture of them with HLB = 10. The effect of water content, temperature and surfactant concentration on the emulsion stability was investigated. The dynamic interfacial tension and thermodynamic properties of the individual and blend emulsifiers were investigated. It was found that the mean sizes of the formed droplet between 45 and 170 nm depend on the water content, temperature and surfactant concentration of blend emulsifiers.

TEM image for water/S2/ kerosene at 8% surfactant concentration, 10% water content, HLB = 10 and 30 °C after 360 h.Figure optionsDownload as PowerPoint slideHighlights
► This figure shows the formation of transparent nano-emulsion with mean particle size (80 nm).
► The water droplet in the nano-emulsion appears as a dark spherical shape.
► The surroundings phase of kerosene is shown as a bright phase.
► The radius of water droplet by TEM is agreed with the data obtained by the dynamic light scattering.