金壽億 , 吳元植 , 金昌奎 , 權赫哲

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The effects of electrolytes (sodium chloride, potassium chloride and calcium chloride) on critical micelle concentration in aqueous solution of a series of polyoxyethylene oleic ester have been studied. Changes in the critical micelle concentration have been followed as a function of concentration of various electrolytes. By the addition of electrolytes the critical micelle concentration is lowered on account of salting out. The surface chemistry effects which results from the included salts are discussed.

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吳元植 , 金昌奎 , 梁三柱

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高鍾星

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梁三柱

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It has been found that W/O/W-type multiple-phase emulsions can be prepared by a two step procedure of emulsification using a variety of nonionic emulsifying agents. The first step in emulsification, providing the W /0 emulsion, was made with an organophilic emulsifying agent such as Span 80, and the second step, providing the W/O/W emulsion, was then carried out by mixing the W/O emulsion with an aqueous solution of a polyoxyethylenetype hydrophilic emulsifying agent. Yield of the W/O/W emulsion was measured by the amount of maker (glucose), which migrated from the dispersed globules to the continuous phase, using dialysis for separating the migrated glucose from the newly prepared W/O/W emulsion, and using Nelson-Somogyi's technique for analyzing the amount of the glucose. The results of the yield measurement for a series of the samples indicate that the significant factor affecting the W/O/W emulsion formation is the ratio of the organophilic emulsifying agent in the oil phase to the hydrophilic emulsifying agent in the aqueous continuous phase. The correlation between the yield of the W/O/W emulsion and the ratio of emulsifying agents used for the two-step in emulsification shows that when one desires a yield of the W/O/W emulsion higher than 90%, the organophilic emulsifying agent needed is 10 times or more the amount of the hydrophilic emulsifying agent.

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李炳純

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The physico-chemical factors influencing the microbial growth and the effectiveness of preservatives in cosmetic emulsions are described. Among the several kinds of factors that affect the microbial growth, such as the water volume, pH, degree of aeration, kinds or concentration of nutrients, particularly the most important is what the type of emulsion is. And the effectiveness of preservatives is largely influenced by the concentration of free preservative in water phase, which is closely related with the physico-chemical condition of emulsion system like pH, the volume ratio, and the kinds or concentration of macromolecules in aqueous phase, those of oil components and surfactants.

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李泰弘

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Measure the effect of initial concentration of surfactant (SDS), centrifugal time, temperature, electrolytes on the amount of oil separated from 50% LP-50% water emulsions. Exponentially increasing, stability with electrolyte concentrations is related with SDS absorption increase and change in absorbed film characteristics. Two of the important factors to have a stable emulsion are elasticity and viscosity of the interfacial film, as Parkinson and Sherman pointed out.

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Yoshimaru Kumano , Shin Nakamura , Sadaaki Tahara , Saburo Ohta

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WATER-IN-OIL (W/O) EMULSIONS STABILIZED by using gels formed between surfactants and aqueous solutions of AMINO ACIDS were studied. The gel can only be obtained with a fluid surfactant which has lipophilic properties and a specific orderly lamellar structure and amino acids or their salts which are readily soluble in water. By dispersing these gels into the oil phase and then adding the water phase, extremely stable w/o emulsions with wide ranges of water content were obtained. This type of emulsification was termed the “gel-emulsification method” by the authors. When this new technology was applied to the preparation of cosmetics, products with outstanding characteristics were obtained. The function of the amino acids in the emulsification were investigated by using physico-chemical methods such as X-ray analysis, nuclear magnetic resonance (NMR), heat of solution, electron microscopy (EM), and measurement of the water content solubilized in the surfactant phase. It may be concluded that the amino acids are effective in forming a tight surface atmosphere around the water particles and in preventing coalescence of water particles by strong hydration effect of the amino acids, thus stabilizing the w/o emulsion.

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