| Summary: | 碩士 === 嘉南藥理科技大學 === 化妝品科技研究所 === 94 === Abstract
Nano-emulsions are composed of oil-water-surfactant mixtures in a thermodynamics stable system. The droplet size of micellar is approximately 10~100 nm. Because of extremely small size, these droplets have weaker light scattering power, they look like transparency or translucency, and also give well penetration into skin. In this study, the influences of non-ionic surfactants on nano-emulsion formation with different carbon chain length and numbers of ethoxy groups by the phase transfer temperature were investigated. The conductivities during phase transitions were measured to evaluvate the phase inversion temperature. A laser-scattering particles size distribution instrument was used to evaluvate the droplet size at 25oC. This research was divided into two parts: the formation of nanoemulsion with single non-ionic surfactant and the surfactants mixed with two surfactants. The results showed that the phase inversion temperatures increase with the surfactants amounts increased, a linear relation was found for surfactants contents and the PIT. The successful emulsion are dependant on hydrophilic-lipophilic balance (HLB) values. The larger or smallier HLB values can not form stable emulsion. The effect of oil contents, thickening agent and ionic strength on the stabilities of nano-emulsion was also discussed. The higher oil contents, the higher PIT. The higher Oswald ripping rates were also found when thickening agent and NaCl concentration increased in solution.
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