O/W 에멀젼의 입자크기 및 상거동에 미치는 다양한 전상유화법의 효과 = Effects of Various Phase Inversion Emulsification Methods on Droplet Size and Phase Behavior of O/W Emulsion

다국어 초록 (Multilingual Abstract)

O/W emulsions were prepared with the various phase inversion emulsification methods. The emulsifiers used were the polyoxyethylene(20)sorbitan monostearate and sorbitan sesquioleate, and the oil used was a liquid paraffin(dispersed phase). A portion of aqueous phase added during the phase inversion emulsification process is solubilized or emulsified into the oil phase to form a W/O primary emulsion. This primary emulsion eventually inverts to form an O/W final emulsion either by changing the dispersed phase volume(a catastrophic inversion) or by changing the surfactant`s affinity for the oil and water phases(a transitional inversion). A short-lived double emulsions of (W/O)/W type were formed in the process of the two-step phase inversion which adopted the direct emulsification method : O/W final emulsion was formed as follows, i.e., W/O→(W/O)/W double emulsion→O/W emulsion. Catastropic inversion occured in the two-step phase inversion emulsification method. In one-step phase inversion emulsification and three-step phase inversion emulsification, fine and homogeneous O/W emulsions were formed as follows, i.e., W/O→pseudomicroemulsion gel phase→O/W. In this method the transitional inversion occurred within constant concentration(5-17wt. ％) of contineous phase. The more fine, homogeneous and viscous emulsion was prepared with the three-step phase inversion emulsification method than that of emulsions prepared with the two-step phase inversion emulsification method. The finest and most stable droplets were formed in 10.0∼10.8 HLB region of mixed surfactants and this HLB region had maximum amount of solubilizing water.