• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.1
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• pp.47-54
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• 2013

Aloe gel microcapsule was prepared by dehydrating dispersed aloe gel droplets in the form of W/O emulsion using a vacuum evaporator. The microcapsules remained in stable suspensions after washing with mineral oil and had a homogeneous spherical structure with diameter less than 6.4 ${\mu}m$. The microcapsule suspension in mineral oil (> 41%) exhibited a step increase in viscosity and shear-thinning but not showed thixotropic behavior with a yield stress higher than 300 Pa. The dense suspension appeared to be semi-solid as the microcapsule fraction increases and to be stable after heat treatment at $105^{\circ}C$ for 15 min. In conclusion, the dense suspension composed of gel microcapsules is expected to provide a basic cosmetic formulation that can be applied to develop various types of aloe gel cosmetic products.

• 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.