• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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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.

• 한국산학기술학회논문지
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• 제9권6호
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• pp.1739-1744
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• 2008

본 연구에서는 현재 국내에서 다량 사용하고 있는 중금속 크롬($Cr^{6+}$)과 납(Pb)이 포함된 녹색안료를 대체하기 위하여 유동층기상증착(FB-VD) 공정을 사용한 무독성 유 무기 복합안료를 개발하였다. 안교제조를 위하여 카올린(Kaolin) 계열의 화합물과 탄산칼슘($CaCO_3$)을 담체로 사용하였으며, 담체들의 표면특성과 구성성분은 SEM과 EDXS를 사용하여 고찰하였다. 또한 안료의 성능을 극대화하기 위하여 다양한 종류의 계면활성제를 사용하고, 그 성능 차이를 고찰하였다. 녹색안료의 색상발현 실험을 한 결과 건조상태나 색상발현에서 녹색물실 배합농도에 차이를 보였으나, 음이온 계면활성제를 사용한 경우 건조와 색상발현에 가장 적합하였다.

• Macromolecular Research
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• 제8권2호
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• pp.80-88
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• 2000

Biodegradable microspheres were prepared with poly(L-lactide-co-glycolide) (PLGA, 75 : 25 by mole ratio) by an oil/oil solvent evaporation method for the sustained release of anti-AIDS virus agent, AZT The microspheres of relatively narrow size distribution (7.6$\pm$ 3.8 ㎛) were obtained by controlling the fabrication conditions. The shape of microspheres prepared was smooth and spherical. The efficiency of AZT loading into the PLGA microsphere was over 93% compared to that below 15% for microspheres by a conventional water/oil/water method. The effects of Preparation conditions on the morphology and in vitro AZT release pattern were investigated. in vitro release studies showed that different release pattern and release rates could be achieved by simply modifying factors in the fabrication conditions such as the type and amount of surfactant, initial amount of loaded drug, the temperature of solvent evaporation, and so on. PLCA microspheres prepared by 5% of initial drug loading, 1.0% (w/w) of surfactant concentration, and 25$\^{C}$ of solvent evaporation temperature were free from initial burst effect and a near-zero order sustained release was observed. Possible mechanisms of the near-zero order sustained release for our system have been proposed.

• 한국응용과학기술학회지
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• 제27권3호
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• pp.257-265
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• 2010

This study concerned about "Gemini type co-surfactant" which has very interesting properties with new components. They were synthesized by reaction of diethylene glycol monoethyl ether and dicarboxylic acid. The structure could be comfirmed with FT-IR and $^1H$-NMR. Surface active properties such as surface tension, evaluated cmc, cloud point, emulsing power were measured respectively at given conditions. Their surface tensions in the aqueous solution were decreased to 33~35 dyne/cm, which was lower than 39 dyne/cm of SDS, and their cmc values evaluated by surface tension method were $5.0{\times}10^{-1}\sim7.5{\times}10^{-1}$ mol/L. And the emulsifying power was excellent in jojoba oil. All of the synthesized Gemini surfactants possessed good water solubility and their cloud point were $48\sim58^{\circ}C$. As results, Gemini surfactants which were synthesized are expected to be applied as O/W emulsifiers.

• 대한화학회지
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• 제57권6호
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• pp.703-711
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• 2013

In the present investigation, kinetic studies of oxidation of formic acid with and without catalyst and promoter in aqueous acid media were studied under the pseudo-first order conditions [formic acid]T ${\gg}[Cr(VI)]_T$ at room temperature. In the 1,10-phenanthroline (phen) promoted path, the cationic Cr(VI) phen complex is the main active oxidant species undergoes a nucleophilic attack by the substrate to form a ternary complex which subsequently experiences a redox decomposition through several steps leading to the products $CO_2$ and $H_2$ along with the Cr(III) phen complex. The anionic surfactant (i.e., sodium dodecyl sulfate, SDS) and neutral surfactant (i.e., Triton X-100, TX-100) act as catalyst and the reaction undergo simultaneously in both aqueous and micellar phase with an enhanced rate of oxidation in the micellar phase. Whereas the cationic surfactant (i.e., N-cetyl pyridinium chloride, CPC) acts as an inhibitor restricts the reaction to aqueous phase. The observed net enhancement of rate effects has been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. The neutral surfactant TX-100 has been observed as the suitable micellar catalyst for the phen promoted chromic acid oxidation of formic acid.

• 청정기술
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• 제14권3호
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• pp.193-203
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• 2008

피혁 제조 공정에서 계면활성제는 세정목적, 분산성 그리고 고착성 등을 부여하기 위해 사용되고 있다. 그러나 기존의 피혁 공정에서 사용되고 있는 계면활성제는 친수성기가 다량 포함되어 있어 향후 피혁 시장에서 요구될 것으로 기대되는 내오염성, 내수성, 내구성 통의 고기능성 특성을 재현하는데 문제점이 있다. 본 연구에서는 기존의 탄화수소 계열의 계면활성제의 문제점을 보완하기 위해서, 탄소-불소의 강한 결합에너지로 인한 표면장력 감소, 분산력 증대, 세정효과, 크롬 흡착력 증대 등의 특성을 나타내는 불소계 계면활성제를 제조하였다. 불소계 계면활성제의 사용으로 피혁 제조 공정의 분산성 증대, 침투력 상승 및 결합력을 향상시켜 크롬 흡착률 증가, 탄닝 폐수 배액의 크롬 함량 감소, 생물학적 산소 요구량, 화학적 산소 요구량의 함량 감소 및 물리적 특성이 향상되는 것을 확인하였다.

• 한국재료학회지
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• 제18권2호
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• pp.73-76
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• 2008

[ $SF_6$ ] gas has been widely used as an insulating, cleaning and covering gas due to its outstanding insulating feature and because of its inert properties. However, the global warming potential of $SF_6$ gas is extremely high relative to typical global warming gases such as $CO_2$, CFCs, and $CH_4$. For these reasons, it is necessary to separate and collect waste $SF_6$ gas. In this study, the effects of a surfactant (Tween) on the formation rate of $SF_6$ gas hydrates were investigated. The $SF_6$ gas hydrate formation rate increased with the addition of Tween and showed a nearly 6.5 times faster hydrate formation rate with an addition of 0.2 wt.% Tween compared to an addition of pure water. This is believed to be due to the increased solubility of $SF_6$ gas with the addition of the surfactant. It was also found that $SF_6$ gas hydrate in the surfactant solution showed two-stage hydrate formation rates with a formation rate that increased rapidly in the 2nd stage.

• 한국지반환경공학회 논문집
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• 제23권12호
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• pp.55-61
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• 2022

대기 중 온난화 가스의 하나인 이산화탄소 감소를 위해 많은 연구들이 수행 중이다. 이 중 이산화탄소 지중저장은 지구온난화 방지를 위한 중요한 공법 중 하나로 주목받고 있다. 하지만, 제한된 공간의 최대한 많은 양의 이산화탄소 저장을 위한 기술의 개발이 필요한 실정이다. 계면활성제의 활용은 이산화탄소 지중저장 효율의 향상에 기여할 것으로 여겨지고 있으나, 이에 대한 연구는 부족한 실정이다. 본 연구에서는 이산화탄소 지중저장 효율 증진을 위해 계면활성제 종류(sodium dodecyl sulfate 및 sodium dodecylbenzene sulfonate) 및 농도, 이산화탄소 주입속도에 따른 2차원 마이크로모델 실험을 수행하였다. 그 결과, 계면활성제의 농도 및 이산화탄소 주입속도가 증가할수록, 이산화탄소 지중저장 효율이 증가함을 확인하였다. 하지만, 한계 농도 및 속도 이상에서는 더 이상 효율 증진이 발생하지 않는 것으로 나타났다.

• 한국응용과학기술학회지
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• 제25권2호
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• pp.205-210
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• 2008

The transformation of the liquid crystal complex made by binding of anionic surfactant, sodium dodecyl sulfate (SDS), into high charge density cationic polymer, the homopolymer of diallyldimethylammonium chloride (PDADMAC) was induced by adding of nonionic surfactants and investigated by means of microscopy and FE.SEM. Among nonionic surfactants in this experiments polyethylene glycol (3 mol) ether of lauryl alcohol (laureth-3) made variation in the complex. The laureth-3 transformed the complex into spherulite vesicle with the size of ca.$100{\mu}m$. This change increased the viscosity and the turbidity of the solution phase separated originally. Microscope showed that they are spherulite particles and polarized microscope suggested they are multi.lamellar liquid crystals. FE-SEM also proved that explicitly.

• Macromolecular Research
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• 제17권3호
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• pp.168-173
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• 2009

This study reports the preparation and characterization of nanohydrogels by using sodium alginate as a model material. Alginate nanohydrogels (ANH) were prepared by emulsification-diffusion method in a w/o system with 1,2-diacyl-sn-glycero- 3-phosphocholin as the lipophilic surfactant. The effects of the alginate to surfactant ratio and the remaining water contents on the mean particle size and swellability of ANHs were investigated in terms of the concentration, agitation speed, and agitation time. The feasibility of using nanohydrogels and their controllability were proved by the water the absorbency of ANHs during a 7-day evaluation by dynamic light scattering. In this work, the mean particle sizes of ANHs could be controlled from 49.2 nm (measured in ethanol phase) to $1.9{\mu}m$ (measured in water phase, after 7 days of water absorption).