• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.3
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• pp.123-128
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• 1998

Dihydroxyacetone (DHA) has been used as a self tanning agent and many emulsion formulations containing DHA have been studied. In an emulsion, many factors which have negative effect on DHP and the resultant DHA decomposition can destabilize the emulsion base. In this study, two kinds of emulsion with 5％ DHA were prepared, O/W type emulsion and Multilamellavesicle (MLV) type emulsion to compare the stabilization effects of both emulsions on the DHA. The OHA concentration was analyzed quantitatively by high performance liquid Chromatography (HPLC), also the pH and viscosity of both emulsions were measured for stability. This process was carried out over 4 months. For HPLC, a bondaclone $C_{18}$ column with a mobile phase of distilled water and UV detector were used. The results of these experiment showed that DHA is more stable in an MLV emulsion than it is in an O/W type emulsion.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.510-516
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• 1997

O/W emulsions were prepared by adding water to the solution containing amphiphilic resin and the mixed emulsifier of cetyl alcohol polyoxyethylene(20) sorbitan monooleate. Phase behavoir of these emulsions was studied at various HLB(Hydrophilic Lipophilic Balance) values and temperatures. The polar oil emulsion containing the amphiphilic resin showed improved phase stability at various temperatures. Model compounds which contain one of the functional groups in the amphiphilic resin were used in the polar oil phase in order to study the effect of interaction between the functional group and the emulsifier on the phase stability of emulsion. These model compound emulsions showed the phase stability order of poly(acrylic acid)

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.3
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• pp.128-133
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• 1997

In manufacturing emulsion lipstick in the past, heat and emulsifyoil phase made with oil, wax and lipophilic emulsifier with water phase together; and then mold above-mentioned materials, so-called lipophilic emulsified lipstick production method has been used. However it is hard to manufacture products using the above said method and furthermore, weak in moisturizing effect, lip care and stability. In this paper, I will discuss about multi-emulsion lipstick complementing already existing emulsion lipstick in terms of stability, giving moisturing effect of lip, and outstanding protection effectiveness of skin by safely gelatinating the state between amphiphilic lipid and water in stable.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.2
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• pp.119-131
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• 2012

The W/O emulsion is widely used for cosmetics because of its water-proofing benefit and long-lasting moisturizing effect. However, because of low stability of the W/O emulsion, it is very important to control the concentration of electrolyte and emulsifying agent, and ratio of water phase. Among these factors, we focused on the effects of different structures of emulsifying agents on the change of stability. Emulsifying agents were sorted into polyglyceryl ester, silicone and sugar series. We also examined the emulsifyingability of emulsifier by changing the ratio of normal and silicon oil in the oil phase. Through these experimental results, we figured out the property of w/o emulsion depending on the types of emulsifiers, and observed the stability of emulsion considering the change of particles and viscosity over time.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1478-1486
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• 2018

Liquid crystals offer plenty of useful activities as improving the stability of emulsion, increasing moisturizing power, drug release, improving skin feeling and visual effect for cosmetics fields. In order to prepare stable semi-transparent gel emulsion, liquid crystal emulsification method was used. The emulsion stabilities of systems containing glycerin, fatty alcohols, surfactants, water and oil were investigated at various temperatures as time passed. The stabilities of all emulsions were evaluated by means of a polarizing microscope, SEM, rheometer, colorimeter and DSC. Even though the samples stored at $50^{\circ}C$ thermostatic chamber were occurred the reduction of hardness, turbidity and ${\Delta}H$ and the peak shift, the semi-transparent gel emulsion was very stable without separation between water and oils phase in emulsion.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.11 no.1
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• pp.21-31
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• 1985

The effect of dispersed phase on the stability of emulsion system with polyoxyethylene dodecyl ethers and their variation of ethylene oxide moles was studied by such methods as interfacial tension measurement, centrifugation and droplet size variation with time. The experiments showed that, in interfacial tension measurement, long chain alkanols into dispersed phaes are more effectively adsorbed onto interface, while long chain alkanes nearly not, and in centrifugation, dispersed phase with alkanols is less separated than that with alkanes. On the other hand, alkanes help more stabilyzing emulsion than alkanols in droplet size variation. And the addition of NaCl or Urea, and variation of E.O. moles have very slight effects on the stability with alkanes than with alkanols. Moreover, the longer carbon chain length is, dispersed phase is more effective on emulsion stability. Supposed from these facts is that more stable emulsion can be made with alkanes which retard molecular diffusion by water solubility decrease rather than alkanols which raise resistance to coalescence by rigid interfacial mixed monolayers formation. In conclusion, the stabilities of these emulsions are proved to be more influenced by molecular diffusion than coalescence.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.469-479
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• 2015

This study is related to the developing method of a transparent sunscreen cosmetic which has waterproofing property and no white turbidity when applied to skin. The transparent sunscreen is prepared by exploiting refractive index difference between oil-phase and water-phase of water-in-oil(W/O) emulsion. The sunscreen according to this study is prepared as a W/O type emulsion so that it is water-stable and water resistance. Also, the stability of W/O type emulsion is developed by adjusting the content of oil phase part and water phase part. As a result of this studying, the transparent W/O emulsion is prepared by adjusting the refractive index of oil-phase and water-phase within 0.004 and it is found that the stability of the transparent sunscreen is increasing when the water phase part is over 75% (w/w) of the W/O emulsion. Through clinical test of transparent sunscreen, the value of sun protection Factor(SPF) and Protection Factor of UVA(PFA) were determined. SPF and PFA values of transparent sunscreen were indicated $30.99{\pm}1.65$ and $3.01{\pm}0.30$.

• Textile Coloration and Finishing
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• v.19 no.1 s.92
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• pp.37-44
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• 2007

In this study, for textile use, the octadecane of phase change materials(PCM) was encapsulated in several micro-diameter shell which prevents leakage of the material during its liquid phase. Microencapsulated PCM(PM) was prepared with the different weight ratio of core material to wall material and by interfacial polymerization methods using polyurea as shell material. Phase stability for O/W emulsion of PCM and PVA aq. (PE) was evaluated by Turbiscan Lab. The capsule formation win identified using FT-IR. Physical properties of microcapsules including diameter, particle distribution, morphology were investigated. Thermal transport properties of suede treated with PM(SPM) were determined by KES-F7 system.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.123-131
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• 2018

Using mixed nonionic surfactants Span/Tween, we investigated the effects of HLB value on the O/W emulsion stability and rheological behaviors. In this study, MS-01 (Span 60 & Tween 60) and MS-02 (Span 80 & Tween 80) was used as mixed nonionic surfactants. We considered required HLB value 10.85 and selected corresponding HLB value range 8-13. The droplet size distributions, droplet morphology, rheological properties, zeta-potential and creaming index of the emulsion samples were obtained to understand the mechanism and interaction of droplets in O/W emulsion. The results indicated that optimal HLB number for O/W emulsions was 10.8 and 10.7, while using MS-01 surfactant and MS-02 surfactant respectively. MS-01 (HLB = 10.8) sample and MS-02 (HLB = 10.7) sample showed smallest droplet size and highest zeta-potential value. Rheological properties are measured to understand rheological behaviors of emulsion samples. All emulsion samples showed no phase separation until 30 days storage time at $25^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.673-679
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• 2004

A microbial cryoprotectant formulation using a W/O/W multiple emulsion system was developed. The psychrotolerant microorganism, B4, isolated from soil in South Korea, was observed by the drop freezing method, in which the microorganism sample inhibited ice nucleation activity. The antifreeze activity was eliminated when the microorganism sample was treated with protease, indicating that the antifreeze activity was due to the presence of antifreeze protein. The result of the l6S rDNA sequencing indicated the B4 strain was most closely related to a species of the genus Bacillus. Culture broth of B4 strain (Bacillus sp.) and rapeseed oil containing 1 % polyglycerine polyricinolate (PGPR) were used as core and wall material, respectively. The most stable W/O emulsion was prepared at a core/oil ratio of 1:2. The highest W/O/W emulsion stability was achieved when the primary emulsion to external aqueous phase containing 0.5% caster oil polyoxyethylene ether $(COG25^{TM})$ ratio was 1:1. Microcrystalline cellulose showed better W/O/W emulsion stability than other polymer types. The viability of cells in a W/O/W emulsion was higher than free cells during storage at $37^\circ{C}$. An acidic pH and UV exposure decreased the viability of free cells, but cells in W/O/W emulsion were more stable under these conditions.