• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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• pp.45-48
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• 1997

Enhancing the electrical conductivity of the ultrathin organic films is one of the important factors for the development of molecular electronic devices. The Langmuir-Blodgett(LB) technique has recently been attracted interest as the a method of deposition ultrathin films. We have fabricated N-docosyl-N'-methyl viologen-diTCNQ(DMVT) anion radical LB film and investigated the optical and electrical conductivity. We have measured UV/visible and FT-lR spectrum. In ESR spectrum, we confirmed that a half-amplitude linewidth is clearly dependent on both temperature and incident angle, which indicates conducting species change. The in-plane electrical conductivity of 21 layers is approximately 1.37$\times$10$^{-6}$ (S/cm).

• 한국응용과학기술학회지
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• 제26권1호
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• pp.102-108
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• 2009

Behaviors of saturated fatty acid halides (CI4, C16, C18) were measured by LB method when the molecules were stimulated by pressure. The saturated fatty acid halides were deposited on the indium tin oxide(lTO) glass by the LB method. The average organic ultra thin film size and the surface roughness of the fatty acid halides thin films were investigated using AFM. It was found that AFM images show small surface roughness ($2.5{\sim}5.0\;nm$) and the organic ultra thin film size of $2.5{\sim}12\;nm$. Both aggregations and pin-holes were also seen on the AFM images. However we found that the surface roughness. These effects seem to be reasonable to be related to the increase of the organic ultra thin film size of fatty acid halides.

• 한국염색가공학회지
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• 제20권5호
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• pp.23-27
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• 2008

In this work, poly(diallyldimethylammoniumchloride) (PDDAC) and meso-tetrakis(4-carboxyphenyl)porphyrin were considered to produce the self-assembly fabrication films. This method is based on the layer-by-layer (LbL) deposition produced by the electrostatic attraction between positively charged PDDAC and negatively charged porphyrin ions. The result of multilayer fabrication was discussed with the level of color strength (K/S). K/S spectra of the fabricated multilayer films showed gradual increase behaviors. In addition, the color photo images of the fabricated multilayer films showed that PDDAC and porphyrin were successfully attracted by electrostatic self-assembly forces.

• 한국식품과학회지
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• 제26권4호
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• pp.411-416
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• 1994

유전자 재조합 대장균에서 분지올리고당을 생산하는 Bacillus licheniformis amylase(BLMA)효소의 생산수율을 향상시키기 위하여 배지최적화 연구를 수행하였다. 기존 LB배지로 5l 발효조에서 배양한 결과 재조합 균주인 E. coli pIJ322의 최대비생육속도(${\mu}_{max}$)는 0.81 hr, 최종균체농도는 1.39g/l, 최종효소역가는 5.11U/ml였다. 배지조성 최적화는 Box and Wilson method에 의한 flask 배양실험으로 수행하였으며, 이 방법으로 결정된 배지조성은 tryptone 18.0g/l, yeast extract 22.4g/l, NaCl 5.3g/l, 포도당 2.1g/l였다. 최적화된 배지로 발효조에서 E. coli pIJ322를 배양한 결과 최종균체농도 6.01g/l, 최종효소역가 23.2U/ml였다. 이것은 기존의 LB배지와 비교하여 최종균체농도 4.3배, 최종효소역가 4.5배 증가한 것이다. 최종효소역가의 증가는 균체농도가 향상되었기 때문인 것으로 추정된다.

• 한국응용과학기술학회지
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• 제23권2호
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• pp.137-146
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• 2006

We investigated the electrochemical properties for Langmuir-Blodgett (LB) films mixed with fatty acid (8A5H) and phospholipid (DLPE, DMPC, and DPPA). LB films of 8A5H monolayer and 8A5H-phospholipid mixture were deposited using the Langmuir-Blodgett method on the indium tin oxide(ITO) glass. The electrochemical properties measured using cyclic voltammetry with three-electrode system, an Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode at various concentrations(0.1, 0.5, and 1.0 mol/L) of $NaClO_4$ solution. A measuring range was reduced from initial potential to -1350 mV, continuously oxidized to 1650 mV and measured to the initial point. The scan rate was 50, 100, 150 and 200 mV/s, respectively. As a result, LB films of fatty acid and phospholipid (8A5H/DLPE and DPPA) appeared irreversible process were caused by only the reduction current from the cyclic voltammogram and LB film of 8A5H-DMPC mixture was found to be caused by a reversible oxidation-reduction process.

• 한국응용과학기술학회지
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• 제32권4호
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• pp.789-794
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• 2015

스테아르산과 인지질혼합물의 농도변화에 띠르는 유기초박막에 대한 안정성을 조사하였다. 스테아르산과 인지질 혼합물 유기초박막은 ITO glass에 LB법을 사용하여 제막하였다. 전기화학적 특성은 $NaClO_4$ 용액에서 3 전극 시스템으로 순환전압전류법을 사용하여 초기 1650 mV에서 최종 퍼텐셜 -1350 mV 까지 측정하였다. 그 결과 스테아르산과 인지질의 혼합물 유기초막은 순환전압전류도표로부터 산화전류로 인한 비가역공정으로 나타났다. 스테아르산과 인지질혼합물 LB막(몰비 1:1, 1:2, 1:3)에서 확산계수(D)는 $0.01N\;NaClO_4$에서 각각 $1.4{\times}10^{-3}$, $1.7{\times}10^{-3}$ 및 $1.6{\times}10^{-3}(cm^2/s)$로 산출되었다.

• Macromolecular Research
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• 제12권6호
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• pp.581-585
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• 2004

A copolymer P[OSA-MI] was synthesized by copolymerization of its corresponding monomers, N-phenyl maleimide (MI) and 2-octen-l-ylsuccinic anhydride (OSA). The polymer (poly[2-[1-(2,5-dioxo-l-phenylpyrroli­din-3-ylmethyl)heptyl]-succinic acid 4-(2-$\{$ethyl-[4-(4-nitrophen-ylazo)phenyl]amino$\}$ethyl)ester]) P[DR1MA-MI] was obtained from the reaction of P[OSA-MI] with 2-[4-(4-nitrophenylazo)-N-ethylphenylamino] ethanol (DR1). A stable monolayer of P[DRIMA-MI] was formed by spreading the solution of the polymer in chloroform. In Y-type Langmuir-Blodgett (LB) films prepared using this Langmuir-Blodgett method, the second harmonic waves generated from adjacent mono layers canceled each other out. In X-and Z-type LB films, the second harmonic intensity increased upon increasing the number of monolayers, but this increase was somewhat smaller than predicted by the square law. This phenomenon is due to defects or imperfect alignment of the dipoles in the LB film. The generation of second harmonic waves from Y-type LB films having an even number of mono layers supports this argument. The degree of imperfection seemed to increase as the number of layers increased. The second-order nonlinear optical properties of spin-cast films of these polymers were also measured. The largest second harmonic coefficient of the poled P[DRIMA-MI] film coated on a glass plate was 19 pm/V.

• 한국응용과학기술학회지
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• 제31권3호
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• pp.359-366
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• 2014

포화지방산과 인지질(DMPC)혼합 LB막에 대한 전기화학적 특성을 조사하였다. 포화지방산과 DMPC 혼합 단분자 LB막은 ITO glass에 Langmuir-Blodgett법을 사용하여 제막하였다. 전기화학적 특성은 $NaClO_4$ 용액에서 3 전극 시스템 (Ag/AgCl 기준전극, 백금선 카운터 전극 및 LB 필름이 코팅된 ITO 작업 전극)으로 순환전압전류법을 사용하여 측정하였다. 그 결과 포화지방산과 인지질(DMPC)의 LB막은 순환전압전류도표로부터 산화전류로 인한 비가역공정으로 나타났다. 포화지방산과 인지질(DMPC)혼합(몰비 1:1) LB막(C14, C16, C18, C20)에서 확산계수(D)는 0.05 N $NaClO_4$에서 각각 $1.2{\times}10^{-3}$, $2.1{\times}10^{-3}$, $1.4{\times}10^{-4}$ 및 $1.1{\times}10^{-3}cm^2/s$로 산출되었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.244.2-244.2
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• 2011

We introduce a novel and robust method for the preparation of nanocomposite multilayers, which allows the excellent photoluminescent (PL) properties as well as the accurate control over the composition and dimensions of multilayers. By exchanging the oleic acid stabilizers of CdSe@ZnS quantum dots (QDs) synthesized in organic solvent with 2-bromo-2-methylpropionic acid (BMPA) in the same solvent, these nanoparticles were be alternately deposited by nucleophilic substitution reaction with highly branched poly(amidoamine) dendrimer (PAMA) through layer-by-layer (LbL) assembly process. Our approach does not need to be transformed into the water-dispersible nanoparticles with electrostatic or hydrogen-bonding groups, which can deteriorate their inherent properties, for the built-up of multilayers. The nanocomposite multilayers including QDs exhibited the strong PL properties achieving densely packed surface coverage as well as long-term PL stability under atmospheric conditions in comparison with those of conventional LbL multilayers based on electrostatic interaction. Furthermore, we demonstrate that the flexible multilayer films with optical properties can be easily prepared using nucleophilic substitution reaction between bromo and amino groups in organic media. This robust and tailored method opens a new route for the design of functional film devices based on nanocomposite multilayers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.238-240
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• 1991

Langmuir-Blodgett(L.B) method is one of the most possible candidate for the fabrication of the micro scale memory or electrical devices. As for a fundamental study on the conduction mechanism in the organic thin membrane, N-alkyl quinolium-TCNQ complexes were synthesized and their physical properties were examined spectroscopically. LB film was produced by using Moving Wall Type LB Apparatus. The average area per molecule (N-docosylquinolium-TCNQ) was $67.97{\AA}^2$ which is ${\AA}^2$ larger than N-docosyl quinolium-TCNQ.