Phase behavior of the alpha-hydroxyoctanoic acid/Laureth 4/white oil/water system and preliminary evaluation of the phase changes during evaporation of its emulsion.

The phase diagram was determined for the alpha-hydroxyoctanoic acid/Laureth 4/white oil/water system using visual observation with an optical microscope. Typical emulsions were evaporated to determine the structural changes. These were compared to those predicted from the phase diagram. Small-angle x-ray diffraction was used to determine the location of the alpha-hydroxyoctanoic acid in the lamellar liquid crystal. The most important result is the fact that irrespective of initial composition, the final result was a suspension of solid acid particles with dissolved oil and surfactant in a surfactant/oil liquid with only minute amounts of solubilized acid.