• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.813-820
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• 2019

The influence of cholesterol on the physicochemical properties of the oleic acid was clarified through the measurements of density, viscosity, IR, $^1H$ NMR, self-diffusion coefficient for the oleic acid samples containing a small amount of additives such as cholesterol, cholestanol, cholestane, cholesteryl oleate, benzene, and ethanol. Cholesterol, possessing one OH group and one double bond in its molecular structure, largely increased the viscosity and reduced the self-diffusion coefficient and the intramolecular movement of oleic acid. Oleic acid forms a complex with cholesterol as well as with ethanol. On the basis of these complex formations and the existence of the clusters composed of oleic acid dimers, it was known the role and the fundamental mechanism of cholesterol to the intermolercular and intramolecular movements of oleic acid in the liquid state.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.02a
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• pp.215-220
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• 2003

인간 게놈 프로젝트가 지속적으로 진행됨에 따라 계속적으로 대량의 유전체 정보가 밝혀지고 있으며, 이미 밝혀진 유전체의 염기서열을 바탕으로 다양한 생물의 전체 유전자의 기능을 효율적으로 해석하는 기술의 개발이 요구되고 있다. 식물 게놈 프로젝트 또한 식량확보라는 단순하면서도 전략적인 차원에서 가장 절실히 요구되는 기본 과학기술 연구분야이다. 게놈(genome)은 유전자(gene)와 염색체(chromosome)의 합성어로 한 생물체가 지닌 모든 유전 정보의 집합체이고, 동종의 재결합 DNA 분자를 포함하는 동일 세포의 개체를 클론(clone)이라 하며, 클론의 집합체를 콜로니(Colony)라 한다 생물체의 모든 유전정보를 가진 게놈은 핵산(nucleotide acid)이라 불리는 염기로 이루어져 있으며, 이들은 서로 상보적인 쌍을 이루어 두 가닥으로 형성되어 있다. 이를 한 쌍의 base pair라 한다. (중략)

• Electrical & Electronic Materials
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• v.6 no.4
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• pp.290-301
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• 1993

최근 전기전자재료 분야에서 유기재료의 초박막화 기술이 주목되고 있다. 유기재료는 구성하는 유기분자에 여러가지 기능을 부여할 수 있기 때문에 무기재료 이상의 기능 또는 무기재료에서는 나타나지 않던 새로운 기능의 발현이 가능하기 때문에 오늘날 관심의 대상이 되고 있다. 이와같이 분자자체가 가지고 있는 기능을 추구하여 가면 궁극적으로는 분자소자의 제안에서처럼 분자를 1개씩 단위로 하여 조립하여 희망의 소자를 구축하는 것이 가능할 것이다. 그러나 현실적으로 우리들 주변에 있는 기술로서 이와같은 분자소자를 실현한다는 것은 아직 시기상조이지만 집합체로서 유기분자를 활용하거나 분자가 가진 기능을 효율 좋게 이용할 수 있다면 현시점에서도 가능할 것으로 생각된다. 따라서 이를 위한 구체적인 방법으로서 박막화가 생각되었으며 그 수단으로서 유기초박막제작기술이 있다.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.41-41
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• 2003

기존의 계통분류는 비교해부학적 및 비교발생학적 방법에 의해 소수의 특징적인 기준형질만을 가지고 상위분류군간의 분류범주를 정하고, 종을 배정하였기 때문에 상당한 인위성이 개입되었고, 이렇게 주관적으로 정리하다 보면 종종 한개의 분류군에 대하여 서로 불일치하는 경우도 있다. 따라서 상위분류군들은 분류군을 구성하는 많은 구성원들이 나타내고 있는 형질의 집합체로서, 다양한 형질에 의해서 다루어져야 한다. (중략)

• Journal of the Korean Applied Science and Technology
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• v.30 no.1
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• pp.16-34
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• 2013

Oleogels may be defined as lipophilic liquid and solid mixtures. The solid lipid materials (oleogelators) with less than 10 wt.% can entrap bulk liquid oil by ways of the formation of network of oleogelators in the bulk oil. The oelogelators can be grouped into two: self-assembly system and crystal particles system. This article reviewed recent work on the formation of oleogels using various types of oleogelators. The fundamental aspects of the formation of lipid network are discussed with a special emphasis on crystal particle based oleogels. The potential applications of oleogels for cosmetics are also described.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1142-1146
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• 1996

Cholesterol-containing surfactant was synthesized, and it was sonicated with monomer in water to form a vesicle solution. This vesicle solution was dried to construct a membrane which had a molecular multilayer structure. Using UV irradiation the monomer in this membrane were polymerized, and then surfactant was extracted by organic solvent. Using a X-ray diffractometer, the thickness of one layer and the regularity of the multilayer were measured. And scanning electron microscopy was conducted for fractured polymer film.

• Journal of the Korean Chemical Society
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• v.38 no.9
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• pp.632-639
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• 1994

For dye sensitization of zinc oxide in the visible region, copper phthalocyanine(CuPc) and sunfast yellow(SY) were adsorbed in two layers on zinc oxide powder. The adsorption structures of $\alpha-and\beta-CuPc$ on zinc oxide were investigated by photoacoustic, IR and Raman spectra. The ${\alpha}-and\;{\beta}$-polymorphs exhibited dimeric structure or molecular aggregates. The surface photovoltaic effect of ZnO/CuPc/SY showed higher than that of ZnO/SY/CuPc and $ZnO/\beta-CuPc/SY$ indicated better photosensitive than $ZnO/\alpha-CuPc/SY.$ Electrophotographic sensitivity of $ZnO/\beta-CuPc/SY$ was $$S_{1/2}=2.99{\times}10^{-2}(erg/cm^2)^{-1}$ at 630 nm.

• Journal of the Mineralogical Society of Korea
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• v.32 no.3
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• pp.151-162
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• 2019

Todorokite, a tunnel-structured manganese oxide, can contain cations within the relatively large nanopores created by the $3{\times}3$ Mn octahedra. Because todorokite is poorly crystalline and found as aggregates mixed with other phases of Mn oxides in nature, the coordination structure of cations in the nanopores is challenging to fully characterize in experiment. In the current article, we report the atomistic coordination structures of $Mg^{2+}$ ions in todorokite tunnel nanopores using the classical molecular dynamics (MD) simulations. In experiment, $Mg^{2+}$ is known to occupy the center of the nanopores. In our MD simulations, 60 % of $Mg^{2+}$ ions were located at the center of the nanopores; 40 % of the ions were found at the corners. All $Mg^{2+}$ located at the center formed the six-fold coordination with water molecules, just as the ion in bulk aqueous solution. $Mg^{2+}$ ions at the corners also formed the six-fold coordination with not only water molecules but also Mn octahedral surface oxygens. The mean squared displacements were calculated to examine the dynamic features of $Mg^{2+}$ ions in the one-dimensional (1D) nanopores. Our MD simulations indicate that the dynamic features of water molecules and the cations observed in bulk aqueous solution are lost in the 1D nanopores of todorokite.

• Membrane Journal
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• v.5 no.2
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• pp.89-96
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• 1995

The monolayer characteristics of phosphate amphiphiles with azobenzene at air/water interface were studied by the measurment of $\pi-A$ curves and absorption spectra. Immediately after being spread on the water surface, these amphiphiles having strong intermolecular hydrogen bonding interactions showed the typical absorption spectra which resulted from domain formation. But the aggregated domains could be controlled by changing the subphase conditions (adding bulky salt and rasing pH). Addition of metal ions in subphase changes the molecular orientation of monolayer. As the metal ion charge increases ($1\leq2$ < 3 < 4 valence), the absorption maximum (310nm) of the amphiphile with azobenzene shifts to a longer wavelength (350nm) which means that the orientation of the amphiphile is tilted. These results suggest that the molecular orientation, and furthermore the aggregation state of monolayer can be possibly controlled by the interaction of metal ions with different charge types.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.101-101
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• 1989

Multilayer films of inorganic analogues of Langmuir-Blodgett films have been prepared on silicon and gold substrates and characterized by ellipsometry, XPS, FT-IRRS, and electrochemical measurements. The deposition technique requires first covalent attachment or adsorption of a phosphonic acid anchoring agent; $HO(CH_3)(CH_2)_2Si(CH_2)_3PO_3H_2$ and $[-S(CH_2)_4PO_3H_2]_2$ were used with Si and Au, respectively. The functionalized substrates are exposed alternately to aqueous $ZrOCl_2$ and l,l0-decanediylbis(phosphonic acid) solutions to yield multilayer films. Surface-sensitive probes show that the films are compact and grow in an oriented fashion suggestive of good structural order.