Formation of orange oil-in-water nanoemullsions using nonionic surfactant mixtures by high pressure homogenizer

The formation of nanoemulsions depends on the size of the droplets formed, the polydispersity and the difference in solubility and/or chemical potential between the small and large droplets. This article reports experiments to evaluate the formation of orange oil/water nanoemulsions in the presence of mixtures of nonionic surfactants, prepared in a high-pressure homogenizer. The surfactant mixtures were prepared to have different HLB values, by varying their type and concentration. The formation and stability of the nanoemulsions were evaluated as a function of the surfactant mixture used and also the processing conditions in the homogenizer. The size and distribution of the droplets formed, along with their stability, were determined in a Zetasizer Nano ZS particle size analyzer. The results showed that the optimal HLB range of the surfactant mixtures to obtain stable o/w nanoemulsions, independent of the processing conditions, is between 11 and 12. Better results were obtained with Unitol®L20/Unitol®L100 mixtures, in which the hydro-phobic surfactant causes a reduction in the interfacial tension and the hydrophilic surfactant promotes steric stabilization of the system.