The study of phase equilibria in a surfactant system by means of phase diagram has been one of the important tools, giving the information about the sequence of phases appearing during the surfactant association process. The aim of this work is to reveal different association structures (such as microemulsions, emulsions and liquid crystals) in various systems of water/hydrocarbon/amphiphile, and show the molecular interactions involved with the addition of a component or by varying the ratio between the components in the system. The association structures and the information gained from phase equilibria study are of implications for cosmetic applications
Cosmetic additives such as mineral oil and sunscreens can be incorporated into microemulsions or liquid crystalline structures. With lamellar liquid crystal present, the location of the additives and water penetration into the amphiphile layer can be determined by the low angle x-ray diffraction
The essence of skin care products is to retain skin moisture and give skin a glossy and healthy look. The final action of the formulation lies in the structure present after the evaporation of volatile components. The results from evaporation studies in the surfactant systems allow to foresee the phase transitions with the depletion of volatile components. The structure changes in the fragrance systems during evaporation are the consequences of the relative vapor pressure of the fragrance and water. Some variables that may influence the fragrance vapor pressure are investigated by headspace GC analysis. A reversible extraction/separation process for a fragrance is also described, in which the calculation for optimization of extraction is facilitated by a computer program
