Evaporation from a Limonene Emulsion

Abstract

A publication to honor the legacy of Per Ekwall, the Finnish colloid chemist, whose research was on the forefront for several decades in the area of colloidal association structures. In the article an algebraic method was applied to obtain information about the conditions during evaporation of the volatile compounds in a system of limonene, water and Laureth 4 (a commercial tetraoxyethylene dodecyl ether). The evaporation path was calculated using published information about the phase diagram of the system and about the vapor pressures of the components at selected compositions. In the calculations intervals between steps were made proportional to the difference between the excess vapor pressure of water at the selected level of relative humidity and its full vapor pressure at zero relative humidity. This calculation method inherently gave linear time dependence of the remaining water in the emulsion because of its constant vapor pressure. The calculations also revealed the amount of limonene to be close to linearly dependent on time. The reason for this latter result was found in the features of the phase diagram; in turn caused by the limonene oil phase being a W/O microemulsion with moderate vapor pressure variation with composition.

Keywords:

• Emulsions
• vapor pressure
• evaporation
• fragrances
• phase diagrams