• 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 Life Science
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• v.20 no.8
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• pp.1241-1248
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• 2010

The solvent extracts of Nelumbo nucifera G. were investigated for antioxidant activities, whitening and anti-wrinkle effects to apply as a functional ingredient in cosmetic products. For their industrial application, the cosmetic products were also prepared with advanced formulation techniques such as W/O/W multiple emulsion. Total phenolic and flavonoids contents increased in Nelumbo nucifera G.-Leaf (NN-L). The electron donating ability of Nelumbo nucifera G.-Flower (NN-F) or Nelumbo nucifera G.-Leaf (NN-L) extracts were above 85% at a concentration of 500 ppm. The superoxide dismutase (SOD)-like activity of Nelumbo nucifera G. (NN-L) extracts was about 60% at a concentration of 1,000 ppm. The xanthine oxidase inhibitory effect of NN-L extract was higher than that of NN-F and NN-S extracts. The tyrosinase inhibitory effect, which is related to skin-whitening, was 36% in NN-F at 1,000 ppm. For anti-wrinkle effect, the elastase inhibition activity of NN-L was about 30% at 1,000 ppm. The results of stability test showed that W/O/W multiple emulsion (ME) containing Nelumbo nucifera G. extracts. The electron donating ability of the ME containing NN-F and NN-L were about 60% at a concentration of 100 ppm. The superoxide dismutase (SOD)-like activity of the ME containing NN-L was 30% at 1,000 ppm. The tyrosinase inhibitory effect, which is related to skin-whitening, was 34% in the ME containing NN-F at 1,000 ppm. In anti-wrinkle effect, the elastase inhibition activity of the ME containing NN-L was about 55% at 1,000 ppm.

• Tribology and Lubricants
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• v.2 no.2
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• pp.27-31
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• 1986

By Bong Goo Rhee, College of Engineering, The Univ. of Won Kwang (344-2, Sinyongdong, Iri-shi, 510 Chunpuk-do, Korea), Yoshitsugu Kimura and Kazumi Okada, Institute of Interdisciplinary Research, Faculty of Engineering, The Univ. of Tokyo(4-6-1 Komaba, Meguro-ku, Tokyo 153, Japan), Katsuyuki Hashizume, Taiho Kogyo(2-47 Hosoya-Cho, Toyoda-Shi 471, Japan) and Chang Heon Chi, The G. S of Chon buk N. Unv. It is empirically known that, in concentrated conjunctions lubricated with O/W emulsions, only the oil is entrained to form elastohydrodynamic films. In the present work, this phenomenon is studied experimentally and the result is compared with a theory Which employes a starved lubrication concept. The experiment is conducted in a four roller machine with 0/W emulsions of varying concentration of oil, i.e. beef tallow, in which the film thickness is determined by detecting the rate of X-ray transmission through the conjunction. Excellent agreement is found between the experimental and the theoretical results.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.25 no.4 s.34
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• pp.65-74
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• 1999

We have studied the stability of W/O high internal phase emulsions(HIPE) containing water, cetyl dimethicone copolyol and oils varying magnesium sulfate in the range 0 to 0.5 wt% and oil polarities, respectively. The rheological consistency was mainly destroyed by the coalescence of the deformed water droplets. The greater the increase of complex modulus was, the less coalescence occurred and the more consistent the concentrated emulsions were. The increasing pattern of complex modulus versus volume fraction has been explained with the resistance to coalescence of the deformed interfacial film of water droplets in concentrated W/O emulsion. The stability is dependent on: (i) the choice of the oil is important, the requirements coincide with the requirements for the formation of the rigid liquid crystalline phases; and (ii) addition of salts the aqueous phase opposes the instability due to coalescence. Increasing the salt concentration increases the refractive index of the aqueous phase. It lowers the difference in the refractive index between the oil and aqueous phases. This decreases the attraction between the water domains, thus increasing the stability.

• Proceedings of the SCSK Conference
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• 1999.10a
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• pp.65-74
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• 1999

We have studied the stability of W/O high internal phase emulsions(HIPE) containing water, cetyl dimethicone copolyol and oils varying magnesium sulfate in the range 0 to 0.5wt% and oil polarities, respectively. The rheological consistency was mainly destroyed by the coalescence of the deformed water droplets. The greater the increase of concentrated modulus was, the less coalescence occurred and the more consistent the concentrated emulsions were. The increasing pattern of complex modulus versus volume fraction has been explained with the resistance to coalescence of the deformed interfacial film of water droplets in concentrated W/O emulsion. The stability is dependent on: (i) the choice of the oil is important, the requirements coincide with the requirements for the formation of the rigid liquid crystalline phases :5; and (ii) addition of salts the aqueous phase opposes the instability due to coalescence:. Increasing the salt concentration increases the refractive index of the aqueous phase. It lowers the difference in the refractive index between the oil and aqueous phases. This decreases the attraction between the water domains, thus increasing the stability.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.4 s.59
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• pp.257-261
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• 2006

The aim of this study is to assess the anti-irritation activities of Rheum undulatum L. extract against various irritants. In order to investigate the anti-inflammation effects of Rheum undulatum L. extract on keratinocytes, we measured the quantities of interleukin 8 (IL-8) and tumor necrosis factor ${\alpha}$(TNF ${\alpha}$) secreted by cultured human keratinocytes. As the results, Rheum undulatum L. extract inhibited the secretion of these cytokines dosage-dependently. We also investigated the anti-inflammation effects of Rheum undulatum L. extract against irritant skin reactions induced by 3 mM Methyl nicotinate. The flush was significantly decreased by application of O/W emulsion containing Rheum undulatum L. extract. In the primary irritation test, when Rheum undulatum L. extract was included in O/W emulsion containing 5.0% lactic acid, its considerable anti-irritation effect was revealed. In a in-use test, we confirmed the excellent anti-irritation effect of O/W emulsion containing Rheum undulatum L. extract.

• Applied Chemistry for Engineering
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• v.21 no.5
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• pp.488-494
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• 2010

Under W/O emulsion method using a homogenizer, ${\alpha}$-alumina powder was prepared to evaluate the effects of experimental conditions on its properties, such as particle shape, extent of aggregation, average particle size and distribution. The experimental parameters were the change of type, quantity and composition of emulsifiers as well as the change of O : W volumetric ratio and agitation rate. As results, in the case of the use of single surfactant of SP80, sphere-like particles could be prepared and the average particle size was hardly affected by the agitation speed more than 16000 rpm regardless of SP80 quantity used. When the extent of aggregation among sphere-like particles prepared using $HLB_m$ = 5 of [SP80 & TW80] was compared with that prepared using SP80 at the same vol% surfactant and agitation speed, the former showed more or less low aggregation phenomena and average particle size was slightly reduced. In addition, the fraction of nano-sized particles with low aggregation was increased by the use of 0.1 vol% n-butanol, as a co-surfactant, with $HLB_m$ = 5 of [SP80 & TW80].

• Journal of the Korean Applied Science and Technology
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• v.16 no.1
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• pp.95-103
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• 1999

In the separation of toluene/n-heptane mixture by the emulsion type liquid membrane in a batch system, the effect of surfactants on the separation factor and membrane stability were studied over the surfactant concentration ranging from 0.1 to 1.5 wt% at the contact time of 5 and 10 minutes and the settling time 5 and 10 minutes. The surfactants used were triethanol amine lauryl sulfate. The separation factor reached its maximum value at the surfactant concentration of 0.5 wt%. It was found that the percentage of membrane breakup reached its minium values and the separation factor showed its maximum value at the surfactant concentration of 0.5 wt%, which confirmed that efficient separation could be effect when emulsion liquid membrane were stable because of low membrane break up.

• Journal of the Korean Applied Science and Technology
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• v.25 no.3
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• pp.395-403
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• 2008

In this study, the characteristics of emulsified fuel were studied. The emulsified fuel which was composed of water and diesel was manufactured by using homogenizer and ultrasonic generator. The more the percentage of water contents increases, the more the density increases to the emulsified fuel. However, the viscosity increased in the 60% of water contents and decreased in the 70% of water contents because the O/W type was formed. The 3 minutes's ultrasonic waves during the irradiation time was appropriate of 16,000 rpm. And the energy density of ultrasonic waves was 87.5J/g. The emulsion stability has improved in the lower temperature, the lower percentage of water contents, and the most stable emulsion state was obtained from 20%(w/w) of water contents. Also, the emulsion stability was related to the HLB values of emulsifiers. Especially, the HLB values of emulsifier were appropriate from 4 to 7 values.

• Applied Chemistry for Engineering
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• v.28 no.2
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• pp.186-192
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• 2017

In this study, water in oil (W/O) emulsion fuel was prepared with surfactant mixture of OIMS90 and NP12 by varying ratio of water to bunker-C oil, surfactant concentration and composition, emulsification time, stirring intensity, temperature and mixing time. Diesel engine performance and exhaust emissions were measured and analyzed with prepared emulsified fuel and compared with those measured using bunker Coil. The results indicated that bunker C emulsion fuel stabilized by surfactant mixture of OIMS90 and NP12 is efficient in reducing emissions of particulate matter, $NO_2$, CO, $CO_2$ and $SO_2$. The biggest reduction in exhaust emission was achieved by using emulsion fuel prepared by OIMS90/NP12 = 4 : 6, 500 ppm of total surfactant concentration and 10% water content at $80^{\circ}C$. Boiler efficiency test measured with emulsion fuel showed excellent energy efficiency compared with bunker C oil.