• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.3
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• pp.221-226
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• 2014

IIn this study, O/W type nano-emulsions were prepared by phospholipid-nonionic surfactant mixtures and octyldodecylmyristate using the phase transition low-energy emulsification method. The nano-emulsions were formed only in the very narrow area of the concentration of mixed surfactant and oil molar ratio of around 1 : 1. The particle size of the emulsions was decreased as adding the aqueous phase into the emulsions after phase inversion point unlike the emulsions formed only with nonionic surfactant. Nano-emulsion was stable at room temperature for more than a month. Thus, the nano-emulsions containing phospholipids can be widely used as a cosmetic formulations.

• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.353-360
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• 2010

This study was carried out to investigate the possibility of solid particles as a stabilizing agent instead of surfactant for preparing emulsions in the cosmetics. The type of emulsions stabilized by solid particles was dependent on wettability of the particles for water and oil. The optimal conditions of emulsions stabilized by solid particles were determined with ratio of water and oil phase, polarity of oils and amount of stabilizers. In the foundation appling the optimal condition of emulsions stabilized by solid particles without surfactant, the stable emulsion type foundation was successfully prepared. As a result, this work indicates that emulsions stabilized by solid particles can be applied to make-up cosmetics.

• Journal of the Korean Applied Science and Technology
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• v.26 no.2
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• pp.117-123
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• 2009

Caprylic/Capric triglyceride-in-water emulsions stabilized by Nikkol HCO-60 and HCO-10 were prepared using emulsion inversion point method at different HLB values. Emulsions with various droplet sizes were formed, and emulsion inversion point was detected by electrical conductivity. The change in emulsion droplet sizes and long term stability were monitored using laser scattering method and visual method. The droplet sizes and stability of emulsions were affected by HLB of surfactant. At emulsion inversion point, the water volume fraction increased as the HLB of surfactants decreased. According to our analysis, this resulted from a tendency of forming the W/O (water-in-oil) emulsion as the HLB of surfactants was decreased. The emulsion inversion point was clearly detected by the microscope and the electric conductivity meter. Nanometer-sized emulsion was obtained at the optimum HLB by using emulsion inversion point method. The main pattern of instability of emulsions in HLB 12 and 13 systems was Ostwald ripening. However, The patterns of instability of emulsions below 11 of HLB systems were Ostwald ripening and coalescence. All emulsions produced with surfactants in the range of HLB 8-13, creaming caused by density difference between water phase and oil phase.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.47-54
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• 2015

PURPOSES : The objective of this study is to evaluate the early adhesive characteristic of asphalt emulsions, including polymer-modified emulsions, for chip seals using the surface energy concept, the bitumen bond strength (BBS) test, and the Vialit test. METHODS : Two general methods, the BBS test and Vialit test, were applied to investigate the bond strength and the aggregate loss, respectively. A new theory, the surface free energy (SFE) theory, was used to evaluate the adhesive characteristic between the emulsion and the aggregate. Based on the theory, the contact angles were measured, and then the surface energy components were calculated. Using those components, the work of adhesion (Wa) was calculated for each emulsion. To ensure reliable results, all the tests were performed under the same conditions, i.e., at $25^{\circ}C$ for 240 minutes of curing time. For the materials, three emulsions (CRS-2, CRS-2L, and CRS-2P) and one aggregate type (granite) were employed. RESULTS AND CONCLUSIONS : Under the same conditions, the modified emulsions showed better adhesive characteristics and curing behaviors than the unmodified emulsions. In addition, there was no significant difference between the various modified emulsions. One of the important findings is that the analysis by Wa presents more sensitive results than other methods. The results of the Wa showed that the CRS-2P emulsion has the best adhesive characteristics. Consequently, the use of modified emulsions for chip seals could prevent aggregate loss and allow open traffic earlier.

• International Journal of Highway Engineering
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• v.16 no.6
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• pp.39-50
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• 2014

PURPOSES : The objective of this study is to evaluate the curing and adhesive behavior of asphalt emulsions including polymer-modified emulsions for chip seals and fog seals. METHODS : For the laboratory testing, the evaporation test, the bitumen bond strength (BBS) test, and the Vialit test are used. Also, the rolling ball test and the damping test are employed to evaluate the curing properties of the fog seal emulsions. In order to conduct all the tests in controled condition, all test procedures are performed in the environmental chamber. The CRS-2L and the SBS CRS-2P emulsions are used as a polymer-modified emulsion, and then unmodified emulsion, the CRS-2, is compared for the evaluation of chip seal performance. For the fog seal performance evaluation, two types of polymer-modified emulsions (FPME-1 and FPME-2) and one of unmodified emulsion, the CSS-1H, are employed. All the tests are performed at different curing times and temperatures. RESULTS AND CONCLUSIONS : Overall, PMEs show better curing and adhesive behavior than non-PMEs regardless of treatments types. Especially, the curing and adhesive behavior of PMEs is much better than non-PMEs before 120 minutes of curing time. Since all the test results indicate that after 120 minutes of curing time the curing adhesive behavior of emulsions, the early curing time, i.e., 120 minutes, plays an important role in the performance of chip seals and fog seals.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.1
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• pp.59-62
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• 2004

To know what happens to the internal structure of emulsions under high shear flow is very important for cosmetic product development because it is highly relevant to the physical degradation of emulsions during the application upon the skin. Here, in order to investigate the response of emulsions against the external shear forces, we designed a new device, .JELLI$^{TM}$ (Joint Electro-rheometer for Liquid-Liquid Inversion) chip, for the measurement of electrical and rheological properties of emulsions under shear flow. By using this device, we examined the real-time changes in conductivities of oil-in-water (O/W) and water-in-oil (W/O) emulsions on the artificial skin during large deformation under shear flow. In this study, O/W and W/O emulsions having various volumes were prepared. After emulsions were homogeneously applied on the artificial skin, the electrical resistance and viscosity changes were monitored under steady shear flow. In case of O/W emulsions, the resistance increased as a function of time. The resistance showed more dramatic increase as the increase of the internal oil phase. It was also found that the viscosity change was proportional to the resistance variation. This phenomenon might be caused by decreased resisting forces against the shear flow because of the breakdown of the internal phase.the internal phase.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.2
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• pp.103-110
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• 2009

The objective of this study is to analyze the influences of fatty alcohols and fatty acids on rheological properties of oil in water (O/W) emulsions using viscosity and rheograms. As the chain length of fatty alcohols and fatty acids lengthened, the viscosity of emulsions was increased. The influence of fatty alcohols on viscosity enhancement was stronger than that of fatty acids. Both stearyl alcohol and cetearyl alcohol, which have carbon chain length similar to lipophilic portion of surfactant used in emulsion preparation, had showed the best increase in viscosity of O/W emulsions. O/W emulsions prepared with fatty alcohols and fatty acids were pseudo-plastic fluid and they showed shear thinning behaviour like as the common cosmetic emulsions. O/W emulsions prepared with cetyl alcohol, cetearyl alcohol and stearyl alcohol were thixotropic fluids and thixotropy increased with an increase in the concentration of fatty alcohols and fatty acids. Also O/W emulsions prepared with fatty alcohols were more thixotropic than those prepared with fatty acids. For the sake of viscosity increase related to O/W emulsions stability and spreadability enhancement related to payoff, it is thought that fatty alcohols are more useful than fatty acids in the O/W emulsions as the emulsion stabilizer.

• KSBB Journal
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• v.27 no.4
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• pp.207-214
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• 2012

Emulsions are mixture of immiscible liquids in which one is dispersed in all over the other. They have been applied to many applications including cosmetics, foods, drug delivery system (DDS), fine chemicals, and chemical separations. Especially, emulsion technology is one of the most useful technique to formulate cosmetics such as eye cream, foundation, and foam cleansing. In general, the emulsions can be generated by mechanical agitation of two immiscible fluids. However, the emulsions obtained by conventional method have limited in stability, monodispersity, and complicate process. We describe here preparation techniques of representative cosmetic emulsions such as liposome, liquid crystal emulsion, nanoemulsion, multiple emulsion, and pickering emulsion. Furthermore, various factors which can control the physical properties of each cosmetic emulsions are briefly discussed.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.258-267
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• 2003

Recently inside nano liposome particles or nano-emulsions which contain tough-melting physiology activity materials or the coefficient of low organism utilization promote the coefficient of organism utilization, so this part has been studied a lot because they can absorb selectly cosmetics, specially physiology activity materials, into the skin. Also, in particle size, cells interstitial lipid interval are 30~50nm, so nano-emulsions that the size is similar to 30~50 nm are made to study for absorbing quickly into the skin. And transparent skin which contains oils in common skin lotion dosage form has become the center of public interest. The used nano-emulsions in this study were unsaturated lecithin/co-surfactant! ethanol/ oil / water. And polysorbate 20/ polysorbate 80/ Dicetyl phosphate/hydrogenated .caster oil/ isoceteth-20/SLS were used in co-surfactant. The used oils were cyclomethicone and caprylic/capric triglyceride. The manufacturing process was that microfluidizer was fixed in 1000bar and transit times were changed from 1 to 10 times. From transparency and particle size, the transparency sequence was SLS> polysorbate 20= polysorbate 80> isoceteth-20> dicetyl phosphate >hydrogenated caster oil and the particle size was small. Specially cyclomethicone nano-emulsions, when we made unsaturated lecithin /SLS /ethanol/water/cyclomethicone, cyclomethicone 5％ was good for transparency. And 20％ of this was used for making transparent skin toner in common skin dosage form.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.4
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• pp.265-269
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• 2010

In this study, we varied emulsifiers and oils for obtaining nano-emulsions with low viscosity using solubilization method. We obtained the stable nano-emulsions with 100 nm droplet size composed with hexyl laurate, ceteareth-20, PEG-40 hydrogenated caster oil, glyceryl stearate, and stearic acid. This nano-emulsion was stable against time. The stability of nano-emulsions was measured through the change of particle size. The cooling process was an important factor for obtaining stable emulsions by solubilization method. Stability of nano-emulions was maximum only when cooled rapidly.