Microemulsions with Mixed Nonionic Surfactants and Flavor Oil

The microemulsion systems composed of water/sucrose laurate/ethoxylated mono-di-glyceride/peppermint oil were formulated and characterized using electrical conductivity and small-angle X-ray scattering. The solubilization capacity of water in the oil is dependent on the surfactant mixing ratio. A static percolation phenomenon was observed in these systems and the water volume fraction percolation threshold was determined. A progressive transformation of water-in-oil to bicontinuous microemulsions, occurring upon dilution with water was revealed for equal amounts of sucrose laurate and ethoxylated mono-di-glyceride in the microemulsions. The periodicity, that is a characteristic length for the domain size of the microemulsions, increases linearly with the increase in the water volume fraction, whereas the correlation length, that is also a characteristic length for the domain size, increases with the increase in the water volume fraction up to a certain value then decreases.