Evaporation from a Fragrance Emulsion

Abstract

The evaporation paths and the variation in vapor pressure during evaporation of limonene from a two-phase emulsion stabilized by a nonionic surfactant were calculated from published phase diagram and vapor pressures. The composition of the vapor was calculated from vapor pressures, and the evaporated vapor was assumed to be close to equilibrium composition. The calculations were made for relative humidities of 0 and 50%. The results showed the variation of the composition of the total emulsion as well as of its two phases as a function of the evaporation path. Furthermore, the weight of the total emulsion, of its two phases, and the remaining weights of water and limonene during evaporation were followed. Finally, the relation between the vapor pressure of limonene and the evaporation path was established. The change in the evaporation rate of water due to the modification of the relative humidity gave rise to a small, but significant, modification of the evaporation rate of the limonene. The influence is indirect, due to the dependence of its vapor pressure on the total composition of the emulsion. A combination of detailed information on the static emulsion features and the vapor pressure enabled an approximate estimation of the time dependence of the evaporation.