• 한국식품과학회지
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• 제29권1호
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• pp.26-31
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• 1997

물을 극미량 함유하는 미수계 효소반응계인 aerosol-OT/이소옥탄으로 구성된 역미셀계내에서 레시친의 일종인 DPPC (dipalmitoyl phosphatidylcholine)의 가수분해반응을 phospholipase $A_2$가 촉매할 수 있었다. 또한 phospholipase $A_2$에 의한 가수분해반응을 정량분석하기 위한 고성능 액체 크로마토그래피에 의한 예민하고 간편한 방법을 고안하였는 바, 이에 의하여 aerosol-OT/이소옥탄 역미셀계내에서 phospholipase $A_2$에 의한 가수분해반응의 동력학적인 분석이 가능하였다. 한편, 여러가지 유화제와 유기용매 중 aerosol-OT와 이소옥탄일 때 효소반응이 가장 효과적이었으며, 반응 적정온도는 $35{\sim}40^{\circ}C$, 적정 pH는 7.0이었다. 또한 역미셀계내에서의 가수분해반응은 수분 함량변화에 민감하였으며, R-값(=[water]/[aerosol-OT])이 10.0일 때 가장 높은 효소활성을 나타내었다. 효소반응을 위한 최적조건하에서의 $K_{m,app.}$ 및 $V_{max.,app.}$는 각각 8.73 mM, 2.83 units/㎎ protein이었으며, 역미셀계내에서 phospholipase $A_2$에 의한 DPPC가수분해반응의 활성화에너지는 12.31 kcal/mole로 산출되었다.

• 한국식품과학회지
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• 제34권5호
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• pp.770-774
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• 2002

대두유 수중유적형 유화액의 산화에 미치는 surfactant micelle의 영향을 규명하기 위하여 수중유적형 유화액에서 continuous phase로 전이되는 ferric iron의 양을 측정하였다. Continuous phase로 전이된 ferric iron의 양은 첨가한 잉여의 surfactant micelle의 농도를 $0.5{\sim}2.0%$로 증가시킬수록, 저장기간이 길어질수록 증가하였다. pH 3.0에서 continuous phase로 전이된 ferric iron의 양은 pH 7.0에서 보다 높게 나타났다. Ferric iron을 함유한 대두유 수중유적형 유화액의 지방산화정도는 hydroperoxide와 headspace hexanal을 측정하여 살펴본 결과 첨가된 계면활성제의 양이 증가할수록 산화는 감소하였다. 이상의 결과로 첨가된 계면활성제에 의해 수중유적형 유화액에서 prooxidant로 작용하는 ferric iron의 위치가 변화되어 산화를 줄일 수 있을 것으로 판단하였다.

• Korea-Australia Rheology Journal
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• 제19권4호
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• pp.227-232
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• 2007

The use of various shearing apparatuses to study the phase behavior of poly(styrene-b-isoprene) diblock copolymer micelles is described. A DMTA rheometer was modified so that one can apply oscillatory shear and obtain the scattering pattern along the shear gradient direction. A cone and plate shear cell was designed to access scattering along the shear vorticity direction, and both oscillatory and steady shear can be applied. The most popular way to employ steady shear on relatively low viscosity fluids is to use a Couette cell, because a high shear rate can be readily achieved without disturbing the sample by overflow. In this work, oscillatory shear was used to obtain a single crystal-like scattering pattern, and thereby to examine the mechanism of the thermotropic transition between face-centered cubic (fcc) and body-centered cubic (bcc) lattices. By applying the steady shear, the response of the fcc lattices to various shear rates is discussed.

• Journal of Pharmaceutical Investigation
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• 제22권3호spc1호
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• pp.17-34
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• 1992

A novel drug delivery system, detergent-phospholipid mixed micelles as proliposomes, for water-insoluble compounds was developed by investigating (i) spontaneous formation of small unilamellar vesicles (SUV) from bile salt-egg phosphatidylcholine mixed micelles, (ii) the molecular mechanism of micelle-to-vesicle transition in aqueous mixtures of detergent-phospholipid, (iii) preparation and screening of a suitable liposomal formulation for a lipophilic drug: solubilization of the drug within the lipid bilayer, evaluation of the solubility limit, and characterization of the resulting product with respect to the physical properties and stability of the drug in the system, and (iv) testing antitumor activity in vitro. The results showed that the new carrier had a strong possibility to be a biocompatible universal formulation for water-insoluble drugs.

• Journal of Magnetics
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• 제13권2호
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• pp.53-56
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• 2008

This study proposes a simple nano-patterning process for the fabrication of magnetic nanodot arrays on a large area substrate. Ni nanodots were fabricated on a large area (4 inches in diameter) Si substrate using the soft lithographic technique using self-assembled surface micelles of Polystyrene-block-Poly(methyl methacrylate) (PS-b-PMMA) diblock copolymer formed at the air/water interface as a mask. The hexagonal array of micelles was successfully transferred to a Ni thin film on a Si substrate using the Langmuir-Blodgett technique. After ion-mill dry etching, a magnetic Ni nanodot array with a regular hexagon array structure was obtained. The Ni nanodot array showed in-plane easy axis magnetization and typical soft magnetic properties.

• Bulletin of the Korean Chemical Society
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• 제27권2호
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• pp.251-254
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• 2006

The formation of polyaniline (PANI) in the reverse micelles of poly(oxyethylene) nonylphenyl ether, $(NP5, H(CH_2)_9Ph(OC_2H_4)_5OH)$, was investigated by small-angle neutron scattering (SANS). The reverse micellar solution containing initiators in the inner part of reverse micelle was prepared with surfactant (NP5), water, cyclohexane and an initiator (ammonium persulfate (APS)). The core-shell sphere model containing smearing effect reveals that the polymerization occurs on the shell layer of the reverse micelles. Shell thickness averages varied from 48 $\AA$ to 109 $\AA$ with increases of monomer concentration.

• 한국응용과학기술학회지
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• 제18권4호
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• pp.249-253
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• 2001

A proposed method of determining the composition of mixed micelles in equilibrium with monomer of known composition is described. The systems were sodium ${\alpha}-sulfonated$ dodecanoyl ethyl esther (${\alpha}-SR_{12}Et$) or sodium dodecyl sulfate(SDS)-polyoxyethylene 23 lauryl ether (Brij 35) un water and in 0.1M sodium chloride solution at $25^{\circ}C$. This technique applies the Gibbs-Duhem equation to the mixed micelles, which is treated as a pseudophase. This proposed methodology, which needs only critical micelle concentration data as a function of monomer composition, is applied to an anionic/nonionic surfactant pair. The calculated monomer-micelle equilibrium is found to be very similar to the much-used regular solution for nonideal systems.

• 농업과학연구
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• 제38권4호
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• pp.711-716
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• 2011

Casein micelles are the basic building block of rennet-induced gels. The stiffness of these gels is increased with reaction time. This is probably due to the continuous participation of activated casein micelles into growing network. Dual binding model of casein micelles, which explains assembly of casein and colloidal calcium phosphate, can provides fairly reasonable explanation for the changes in mechanical properties of rennet-induced gels made from different milk pHs and varying colloidal calcium phosphates. The changes in stiffness of these gels would be used for controlling textural properties of cheeses.

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3735-3739
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• 2010

Branched oligopeptides prepared by coupling a very hydrophobic aspartic diamino acid ethyl ester such as Asp $(LeuEt)_2$, $Asp(IleEt)_2$ and $Asp(PheEt)_2$ to glycine or glycylphenylalanine were grafted to the cyclotriphosphazene backbone bearing an equimolar hydrophilic poly(ethylene glycol) (PEG). The properties of the resultant amphiphiles were examined in comparison with those of the linear oligopeptide analogues previously reported. All cyclic phosphazene trimers grafted with the branched tetra- and pentapeptides displayed a normal trend of thermosensitivity depending on their hydrophilic to hydrophobic balance, but the stability and particle size of their micelles were found to be greatly dependent on the fine structure of the branched oligopeptides grafted. The trimers bearing branched tetrapeptides with a low hydrophobicity were found to form unstable micelles initially, which reassemble into thermodynamically more stable polymersomes.

• 대한화장품학회지
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• 제42권1호
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• pp.9-13
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• 2016

마이셀을 이용한 가용화 제형은 화장품 산업에서 스킨 로션, 토너, 미스트 등 다양한 제형으로 이용되고 있다. 마이셀은 입자 자체가 매우 작기 때문에 효능 물질의 담지체 역할보다는 향을 가용화시키는 정도로 활용되고 있다. 본 연구에서는 효능 물질인 ${\beta}$-sitosterol을 담지 할 수 있는 새로운 마이셀을 개발하기 위하여 투명한 외관을 갖는 swollen micelle을 고려하였다. 특히, 효능 성분과의 용해도 계수를 고려하여 swollen micelle을 제조함으로써 난용성 효능 성분이 마이셀 내부에 안정하게 존재할 수 있는 새로운 방법을 개발하였다. 이렇게 만들어진 swollen micelle의 안정도는 동적광산란장치(dynamic light scattering, DLS)를 이용하여 확인하였고, 투명한 입자의 외관과 모양은 육안 관찰 및 cryo-TEM을 통해 확인하였다. 또한, DSC를 이용한 열분석을 통해 난용성 효능 성분인 ${\beta}$-sitosterol이 swollen micelle 내에서 안정하게 존재함을 확인하였다. 본 연구를 통해 용해도 계수를 고려한 swollen micelle은 난용성 효능 성분의 새로운 담지체로서 이용할 수 있음을 확인하였다.