• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.1
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• pp.15-28
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• 2016

Water-in-oil emulsions including water-in-ester oil and water-in-silicone oil (W/O+S) have various advantages such as blocking moisture evaporation and forming air permeable membrane. However, their applications have been limited due to the poor stability under low viscosity condition. In this study, we investigated the effect of synergistic interaction between nonionic surfactant, micro-size particles and cationic surfactant on the stability of W/O+S formulation. The stability of W/O+S emulsions was changed as a function of cationic surfactant concentration where it increased at lower concentration and then started to decrease above a critical point. Finally, emulsion phase inversion occurred at a high concentration. The results suggest that W/O+S emulsions of low viscosity ranging from 2000 to 5000 cps can be stabilized under the conditions where a nonionic surfactant, micro-size particles and a cationic surfactant are used in the range of 1.0 ~ 4.0 wt%, 2.5 wt% and 0.1 ~ 0.5 wt%, respectively.

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.667-675
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• 2016

Nanoemulsions are actively used in several applications for pharmaceutical, cosmetic and chemical industries. In this study, we propose the use of microfluidizer known as high pressure homogenizer to prepare lipid nanoemulsion as a potent cosmetic delivery carrier. The lipid nanoemulsions were prepared by O/W emulsion with hydrogenated lecithin and different type of oils. Effects of oil type on the stability of the lipid nanoemulsion were investigated with Dynamic Light Scattering (DLS) and Zeta-potential. Arbutin was used as model drug for transdermal administration through hairless mouse skin. Transdermal arbutin delivery using the lipid nanoemulsions was studied with HPLC method.

• Food Science and Preservation
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• v.7 no.4
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• pp.373-379
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• 2000

The Ulmi corex extract was prepared using various solvents to investigate the availability as a natural antioxidant. The extracts were added to lard emulsion and the antioxidant activities were compared. The extract that had a greater antioxidant activity was fractionized. Then the antioxidant activity and substrate specificity of the fraction were examined and optimum concentration of addition was determined. To observe the antioxidative effect of the fraction in vivo, an inhibition rate of lipid peroxidation from which might be derived was measured using a microsome in rat's liver. Among the extracts of Ulmi cortex, the extract from water had the best antioxidant activity, and the addition of 0.05% (w/w) of ethyl acetate fraction showed similar antioxidant activity to a synthetic antioxidant, butylated hydroxyanisole(BHA). Ethyl acetate fraction (0.05%, w/w) also presented the antioxidative effect in lard, soybean oil, palm oil, and com oil. The inhibition of lipid peroxidation in liver microsome showed feater in the ethyl acetate fraction than caffeic acid in both nonenzymatic peroxidation (Fe$\^$++/ascorbate system) and enzymatic peroxidation (Fe$\^$++/-ADP/NaDPH system).

• Clean Technology
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• v.14 no.4
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• pp.256-264
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• 2008

In this study, using PBAST (poly(butylene adipate-co-succinate-co-terephthalate)) which was eco-friendly biodegradable aliphatic polyester, PBAST/PVA (poly(vinyl alcohol)) double-layered hollow microspheres were prepared with the water/oil/water multiple emulsion ($W_1/O/W_2$) method. The double-layered hollow microspheres were manufactured with the yield of 30.92% when the concentration of polymer PBAST in organic phase was 5 wt%, the concentration of PVA in inner aqueous phase was 5 wt%, the volume ratio of $W_1/O$ emulsion to outer aqueous phase was 1:4.5, and when co-surfactants that had large gap in HLB (hydrophile-lipophile balance) value were used. The bulk density of prepared hollow microsphere was 0.180 g/ml and particle size was $1.5{\sim}3\;{\mu}m$.

• Journal of the Korean Applied Science and Technology
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• v.28 no.1
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• pp.1-5
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• 2011

In this study, We investigated the properites of nano-emulsions containing hydrogenated lecithin prepared by high pressure homogenizer. The size of droplet of emulsions prepared by homogenizer at various rpm (rotation per minute) was not measured due to the unstability of emulsions, however, the size of droplet of nano-emulsions prepared by high pressure homogenizer was around 300 nm and the appearance of emulsions was bluish. The stability of emulsions with various lecithin concentration was tested against time. POV (Peroxide value) of emulsions were plotted against time. POVs of emulsions prepared with an egg lecithin and a soy lecithin were increased with time, however, POV of emulsion with Lecinol S-$10^{(R)}$ was kept constant within 60 hours and at $60^{\circ}C$. In consumer test, the nano-emulsion showed higher affinity regardless of skin type. Both of irritation scores of emulsions were similar.

• KSBB Journal
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• v.29 no.5
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• pp.385-391
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• 2014

In this study, the emulsion dispersion stability of optimizing storage temperature was investigated. The system was based on oil/water (O/W) emulsions. In order to evaluate the stability, mean diameter of droplet was measured as a function of temperature with various mixed hydrophilic lipophilic balance (HLB). In addition, the correlations between phase inversion temperature (PIT) and the optimum storage temperature were probed. In this system, majority of the smallest droplet was shown at temperature of $20^{\circ}C$ below PIT. Whether the temperature was increased or decreased from the optimum, size of the droplet increased. According to the mixed HLB, the particle size and optimum storage temperature were also affected. As the concentrations of surfactant were increased, the size of particle decreased with lower optimum temperature for storage. If the surfactant (4 wt%) were mixed with HLB, the optimum storage temperature was $21^{\circ}C$ for maintaining the size of smallest droplet at 108.3 nm in diameter. At above optimum condition, increased size of particle was observed approximately 4 % increases from 108.2 nm to 112.3 nm after 600 hours. The size of particle in emulsion was maintained stably without any considerable effect of Ostwald ripening phenomena at the optimum storage temperature with low polydispersity index.

• Korean Journal of Materials Research
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• v.1 no.2
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• pp.71-76
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• 1991

The superconducting powders in $YBa_2Cu_3O_{7-x}$ and Bi-Pb-Sr-Ca-Cu-O system were easily prepared from water in oil type emulsion by loading each cation into the aqueous phase. In $YBa_2Cu_3O_{7-x}$ system, the superconducting orthorhombic phase was formed by calcining at $750^{\circ}C$ for 10h in $O_2$. The size of the superconducting phase powders was submicron. The density of the sintered specimen using this powders was about 95% of the theoretical density and the resistance sharply decreases at about 90K, In Bi-Pb-Sr-Ca-Cu-O system the low Tc phase($(Bi, Pb)_2Sr_2Ca_1Cu_2O_y$) was formed by calcining at $800^{\circ}C$ for 10h in a low oxygen partial pressure of 1/20 atm The shape of clacined powder is thin plate of which size is about $2\mu\textrm{m}$ and thickness is smaller than $\mu\textrm{m}$. It was observed that the high Tc phase ($(Bi, Pb)_2Sr_2Ca_2Cu_3O_y$) was formed by sintering at $850^{\circ}C$ for 30h in oxygen pressure of 1/20 atm without intermediary grinding. The above sintered sample exhibited superconductivity with a Tc(zero)=105K.

• Membrane Journal
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• v.14 no.4
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• pp.275-288
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• 2004

Carbon dioxide was absorbed into water-in-oil (w/o) emulsion composed of aqueous 2-amino-2-methyl-1-propanol (AMP) droplets as a dispersed phase and benzene solutions of polybutene and polyisobutylene as a continuous phase in a flat-stirred vessel to investigate the effect of non-Newtonian rheological behavior on the rate of chemical absorption of $CO_2$, where the reaction between $CO_2$ and AMP in the aqueous phase was assumed to be a pseudo-first-order reaction. It was expressed that PIB with elastic property made the rate of chemical absorption of $CO_2$ accelerated by comparison of mass transfer coefficient of $CO_2$ in the non-Newtonian liquid with that in the Newtonian liquid.

• Korean Journal of Food Science and Technology
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• v.50 no.3
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• pp.324-330
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• 2018

In this study, we examined the effects of carrier oil type (MCT oil: MO, corn oil: CO, palm oil: PO), pH of dispersion solution, and antioxidants on the chemical degradation of ${\beta}$-carotene in oil-in-water nanoemulsions. The pH of the emulsion had a significant influence on the stability of ${\beta}$-carotene, which showed rapid degradation in emulsions at low pH value and relatively higher stability at high pH values. The influence of the carrier oil type on ${\beta}$-carotene stability was assessed. The rate of ${\beta}$-carotene degradation increased in the following order: CO > PO > MO. The effect of antioxidants on ${\beta}$-carotene degradation was monitored during storage at $25^{\circ}C$ for 4 weeks. The rate of ${\beta}$-carotene degradation decreased upon addition of water-soluble (ascorbic acid) or oil-soluble (tocopherol) antioxidants. In general, tocopherol was more effective than ascorbic acid in reducing ${\beta}$-carotene degradation. To utilize this nanoemulsion for producing acidic beverages, adding a higher concentration of antioxidants is required.

• Membrane Journal
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• v.8 no.4
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• pp.203-209
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• 1998

The cutting oil emulsion microfiltration was carried out on dead-end call and crossflow systems equipped with 0.22 $\mu$m GVHP Millipore and 0.2 m stainless steel Mott microfiltration membranes, respectivdy. The oil drop size in the emulsion was varied from 0.07 to 0.22 $\mu$m. Cake filtration(CFM) and standard pore blocking models(SPBM) were applied to predict the permeation flux. The permeation fluxes of 0.01 vol% oil emulsion followed CFM for dead-end system very well under the condition of 400 rpm and below 100 kPa. The SPBM was, however, suitable for the permeation flux at 400 rpm and above 150 kPa. The oil layer on the membrane surface was destroyed and reproduced repeatedly as operating pressure was suddenly changed from 60 to 200 kPa, and then returned to 60 kPa. Also, we estimated the critical entry pressure(CEP) which is changed from CFM to SPBM, and CEP for dead-end system was around 100 kPa. The CEP increased from around 100 to 150 kPa for the crossflow system as the oil concentration increased from 0.01 to 0.03 vol% when Reynolds number was 7080.