• Title/Summary/Keyword: Emulsions

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STUDY OF STABILITY AND EFFECT OF COLLOIDAL SILVER IN VARIOUS EMULSIONS (Colloidal Silver Emulsion에서 안정성과 효능, 효과에 관한연구)

  • 지홍근;윤경로
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.24 no.1
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    • pp.48-73
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    • 1998
  • Colloid refers to dispersed particles of solid or liquid having diameters of $10^{-5}$ to $10^{-7}$cm, among which colloidal silver is produced by electrolysis. Colloidal silver of various concentrations according to charge and time were formed, antimicrobial activity of colloidal silver was measured. And, the optimum conditions for emulsion were determined by changing the concentration of coloidal silver. Also, the stability of the emulsion was measured by zeta potential and chroma meter by applying colloidal silver to creams(W/S, O/W, MLV)

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Nanofood and Its Materials as Nutrient Delivery System (NDS)

  • Kim, Dong-Myong;Cho, Gyu-Seong
    • Journal of Applied Biological Chemistry
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    • v.49 no.2
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    • pp.39-47
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    • 2006
  • Incorporation of bioactive compounds such as vitamins, probiotics, bioactive peptides, and antioxidants into Nutrient Delivery System (NDS) for 'nanofood' provides simple way to develop novel functional foods that may have physiological benefits or reduce risks of diseases. As vital nutrient in nanofood, proteins possess unique functional properties including ability to form gels and emulsions, which allow them to be ideal nanofood materials for encapsulation of bioactive compounds. Based on protein physico-chemical properties, this review describes potential role of nanofood materials for development of NDS in hydrogel form, micro-or nano-particles. Applications of these nanofood materials to protect delivery-sensitive nutraceutical compounds are illustrated, and impacts of particle size on release properties are emphasized.

Preparation of $Al_2O_3$-$ZrO_2$Composite Powders by the Use of Emulsions(IV) : Emulsion-Spray Pyrolysis Method (에멀젼을 이용한 $Al_2O_3$-$ZrO_2$ 복합분체의 제조(IV) : 에멀젼-분무열분해법)

  • 현상훈;김동준
    • Journal of the Korean Ceramic Society
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    • v.27 no.8
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    • pp.955-964
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    • 1990
  • A new process of emulsiion-spray pyrolysis for synthesizing ceramic powders was developed and the characteristics of Al2O3-20w/o ZrO2 composite powders prepared by this method were investigated. The composite powders synthesized in this study were spherical dense particles with 0.1~0.4${\mu}{\textrm}{m}$ of diameter. As found in powders derived by the emulsion-hot kerosene drying method, all zirconia in Al2O3-20w/o ZrO2 powders heat-treated at 120$0^{\circ}C$ was in the tetragonal form at room temperature. The relative density and the fracture toughness of composites sintered at 1$650^{\circ}C$ for 4hrs were 95% and 5.2MPa.m1/2, respectively.

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Nanoemulsions and Nanoparticles Employed as Delivery Vehicles for Topical Active Ingredients to Enhance Stability and Efficacy

  • Arthur Georgalas
    • Proceedings of the SCSK Conference
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    • 2003.09b
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    • pp.307-307
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    • 2003
  • Strategies to make finished products more stable and efficacious can take advantage of formulation technologies- ingredients and techniques - to improve their delivery into the skin by both enhanced penetration and delayed release. Nanometer range particles and emulsion droplets can be formed with a selection of either silicone copolyol or conventional organic surfactants and dispersion shear rates sufficient to generate stable submicron droplets. By incorporating these into systems with biomimetic liquid crystalline gel networks in either simple or multiple phase emulsions the skin delivery can be enhanced as shown in tape stripping experiments. Such systems can stabilize labile actives, such as Vitamin C and retinol, and aid delivery. Laboratories in U.S and Europe investigated actives including green tea polyphenols, salicylic acid and methyl and benzyl nicotinate.

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Study on nanoemulsion using various lecithins and oils

  • Park, Byung-Gyu;Lee, Sung-Won;Chai, Hee-Gil;Eom, Sang-Yong;Kim, Jong-Heon;Ji, Hong-Geun
    • Proceedings of the SCSK Conference
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    • 2003.09b
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    • pp.379-391
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    • 2003
  • Nanoemulsions have many specific characters compared with general emulsions in aspect of stability, rheological property, uniformity, high interfacial tension and so on. Therefore we study on nanoemulsions with changing various lecithins and oils using microfluidizer. As lecithins, we used saturated lecithin, unsaturated lecithin and hydrogenated phosphatidylcholine. Caprylic capric triglyceride, Squalane, Macadamia nut oil, Liquid paraffins, Dimethicone, and Cyclomethicone were used as oils. To identify nanoemulsions, we measured paticle size, zeta potential, turbidity and transmission electron microscope.

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Fluorescent Magnetic Silica Nanotubes with High Photostability Prepared by the Conventional Reverse Micro-Emulsion Method

  • Zhang, Yuhai;Son, Sang Jun
    • Bulletin of the Korean Chemical Society
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    • v.33 no.12
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    • pp.4165-4168
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    • 2012
  • Magnetic fluorescent silica nanotubes were fabricated using reverse micro-emulsions coupled with conventional sol-gel methods. Anodic aluminum oxide templates were used to separate spatially the magnetic and the fluorescent moieties on individual nanotubes and so prevent quenching of the fluorescence. C18 and fluorescent layers were deposited sequentially on silica. Magnetism was then obtained by the introduction of pre-made magnetic nanoparticles inside the nanotubes. The photo- and chemical stabilities of nanotubes were demonstrated through dye release and photobleaching tests. The produced nanotubes did not show fluorescence quenching upon the addition of the nanoparticles, an advantage over conventional spherical fluorescent magnetic nanoparticles. High photostability of nanotubes, magnetism and biocompatiblily make them potentially useful in bioanalysis.

APPLICATION OF STABLE EMULSIONS TO LIPASE IMMOBILISED MEMBRANE REACTORS FOR KINETIC RESOLUTION OF RACEMIC ESTERS

  • Giorno, Lidietta;Na, Li;Drioli, Enrico
    • Proceedings of the Membrane Society of Korea Conference
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    • 2003.07a
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    • pp.65-68
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    • 2003
  • The paper discusses the use of stable emulsion, prepared by membrane emulsification technology, to improve the enantiocatalytic performance of immobilised lipase in multiphasic membrane reactors. The production of optical pure (S)-naproxen from racemic naproxen methyl ester has been used as model reaction system. The enzyme was immobilised in the sponge layer (shell side) of capillary polyamide membrane with 50 kDa cut-off, The O/W emulsion, containing the substrate in the organic dispersed phase, was fed to the enzyme membrane reactor from shell-to-lumen. The results evidenced that lipase maintained stable activity during all the operation time (more than 250 hours), showing an enantiomeric excess (96 $\pm$2%) comparable to the free enzyme (98 $\pm$ 1%) and much higher compared to similar lipase-loaded membrane reactors used in two-separate phase systems (90%). The study showed that immobilised enzymes can achieve high stability as well as high catalytic activity and enantioselectivity.

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In vitro SPF Measurement of Sunscreen Agents in Cosmetics (화장품에서 자외선 차단제의 in vitro SPF 측정)

  • Yang, Jae-Chan
    • Journal of the Korean Applied Science and Technology
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    • v.27 no.3
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    • pp.370-377
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    • 2010
  • This study evaluated SPF (Sun Protection Factor) of various quntity and kind of sunscreen ingredients which is used in O/W and W/O emulsion by systematic and quantitative approach. Octylmethoxycinnamate(OMC), Buthylmethoxydibenzoylmethan (BMDM), Octocrylene (OC), Octylsalicylate(OS), Octyl Triazone (OT), Titanium dioxide (TD) are used for the experiment. As a result, when different chemical sunscreen ingredients are added to OMC, the synergy effect of SPF was high in order of BMDM, OC, OS, OT. There was no significant difference in O/W and W/O emulsions. It can be a guide to use sunscreen ingredients effectively when the relation between the results of in vitro SPF and in vivo SPF is comprehended.

Preparation and Properties of Anionic Water-Dispersed Polyurethane Containing Polypropylene Glycol and Casein

  • Lee, Joo-Youb
    • Journal of the Korean Applied Science and Technology
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    • v.34 no.4
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    • pp.778-786
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    • 2017
  • In this study, analyzed the changes occurred after adding casein emulsions to water - dispersed polyurethane using polypropylene glycol (PPG). For this purpose, anionic water - dispersed polyurethane containing PPG, IPDI and DMPA and casein emulsion prepared by dissolving casein in distilled water using ammonia water were prepared. As a result of measuring the alkali resistance by using the prepared resin, there was no change in the physical properties. The tensile strength of the sample having a high casein content was measured to be $2.227kgf/mm^2$. Elongation was measured at 474% for samples containing less casein and The abrasion resistance was measured as 46.090 mg.loss of sample containing much casein as a result of the surface roughness measurement.

A Quantitative Analysis Method for Studing AKD Hydrolysis (AKD 가수분해 연구를 위한 정량분석 방법)

  • 민춘기;신동소
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.30 no.3
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    • pp.29-37
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    • 1998
  • In order to set up a proper AKD quantification method for studing AKD hydrolysis, a quantitative analysis method using Uv/vis spectroscopy was evaluated and compared to the conventional GC-MS analysis. Hydrolysis rates of AKD emulsions during storage at 4$0^{\circ}C$ were measured by the UV/vis analysis. Owing to its simplicity and capability of measuring the unreacted AKD significantly even in a small amount, UV/vis method proved to be more suitable for studing AKD hydrolysis than GC-MS analysis. AKD hydrolysis was affected by the types of emulsifiers. Polymer stabilized AKD emulsion hydrolyzed more rapidly than starch stabilized AKD.

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