EVAPORATION RATE FROM AEROSOL OT-WATER-N-HEPTANE INVERSE MICELLAR SYSTEMS

The evaporation rate of aerosol OT-water-n-heptane inverse micellar sy stems was studied. The evaporation behavior of solutions was strongly affected when compared with pure heptane. The changes are related to t he structure of the micelles and the properties of the water molecules dissolved in the micelles. The initial rate of evaporation reaches a maximum when the surfactant head groups are hydrated with three water molecules, a minimum when the first hydration shell of Na+ ions is com pleted, and then rises and stabilizes until the second hydration shell is completed. The presence of free water when the ratio water molecul es to surfactant molecules exceeds 12 produces a new rise of the initi al evaporation rate, which is always higher than that of pure n-heptan e.