PHASE-EQUILIBRIA AND EVAPORATION RATES IN A 4-COMPONENT EMULSION

The cosmetic system of water, lecithin, polyethylene glycol (M.W. 5000 ), and white oil was studied and the phase diagram determined using vi sual observation, low angle x-ray diffraction and chemical analysis. T he results showed the lecithim / water lamellar liquid crystal to be r etained when the polyethylene glycol was gradually replaced by white o il. The polyethylene glycol was solubilized in the lamellar liquid cry stal to a maximum level of 10%, the white oil to 8%. The evaporation r ate, from a thin layer, was followed gravimetrically. The existing str uctures as the evaporation proceeded were identified optically. Evapor ation of water from the three phase emulsion lead to crystallization o f the polymer in the previously existing water droplets, leading to a four phase system of polyethylene glycol, polyethylene glycol/water, L LC, and white oil.A dramatic decrease in the loss rate of water was ob served when all four components co-exist in equilibrium.