Geranyl acetate emulsions: Surfactant association structures and emulsion inversion

Three emulsions of geranyl acetate (GA)-in-water (W) with identical GA/W ratios and varying surfactant (S), Laureth 4, a commercial C12EO 4 compound, fractions were investigated for nature and stability. The emulsions with up to 6% surfactant were W/O, as expected with respect to the solubility of the surfactant in the oil. At 10% surfactant, the aqueous phase became the continuous one and the apparent stability of the emulsion was significantly enhanced.Analysis of the phase diagram and experimental evidence showed the high water content emulsion to be a liquid crystal-in-water emulsion; a kind that did not change even at extreme O/W and LC/W ratios.

Graphical abstractThe figure represents the inversion from W/O to O/W of a geranyl acetate emulsion stabilized by Laureth-4 with a modest increases of surfactant fractionFigure optionsDownload full-size imageDownload as PowerPoint slide