• Title/Summary/Keyword: LB (Langmuir-Blodgett)

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A Study on Electrical Properties of Dendrimer (덴드리머의 전기적 특성 연구)

  • Choi, Yong-Sung;Song, Jin-Won;Lee, Woo-Ki;Lee, Kyung-Sup
    • Proceedings of the KIEE Conference
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    • 2006.07c
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    • pp.1330-1332
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    • 2006
  • In the Langmuir-Blodgett (LB) technique, a monolayer on the water surface is transferred onto a substrate, which is raised and dipped through the surface. From this, multilayers can be obtained in which constituent molecules are periodically arranged. The LB technique has attracted considerable interest in the fabrication of electrical and electronic devices. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The agobenzene dendrimer is one of the dendritic macromolecules that include the azo-group exhibiting a photochromic character. Due to the Presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current.

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Displacement current of monolayer film on the water surface (수면상 단분자막의 변위전류)

  • 송경호;박태곤;박근호
    • Electrical & Electronic Materials
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    • v.9 no.7
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    • pp.674-679
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    • 1996
  • Using the home made Kuhn type LB (Langmuir - Blodgett) film's deposition apparatus, We measured the displacement current of monolayer film on the water surface. The obtained displacement current had each different pattern by the kind of solution while varying pressure of the monolayer. Solution of 4 - octyl - 4' - (5 - carboxyl - pentamethyleneoxy ) - azobenzene (8A5H) and stearic acid (CH$_{3}$(CH$_{2}$)$_{16}$COOH) (C18) were spreaded at the air water interface respectively, and the current induced by the dynamic behavior of molecules were pressed by barrier. Displacement current of 8A5H measured small current than C18 at same condition and it was positive direction when increasing pressure but it was negative direction when decreasing pressure. Also, Two patterns of displacement current were symmetrical form and appeared repeatedly. The C18 has unsymmetrical form of displacement current and weak current when decreasing pressure (expansion). The C18 molecules have two distinct peak values of displacement current that show that the orientations of molecules were changed largely at this points. From these results, we obtained that the 8A5H has more elasticity than the C18.8.C18.

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Local Photoswitching Effects of Cytochrome c/Viologen/GFP Hetero-Thin Film

  • Yu, Chang-Jun;Choe, Jeong-U;Park, Se-Jeong;Nam, Yun-Seok;O, Byeong-Geun;Lee, Won-Hong
    • 한국생물공학회:학술대회논문집
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    • 2001.11a
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    • pp.823-826
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    • 2001
  • In the initial process of photosynthesis, a biological electron transfer system, photoelectric conversion occurs and then long-range electron transfer takes place very efficiently in one direction through the biomolecules. The metal/insulator/metal structured device consisting of GFP, viologen, cytochrome c hetero-thin film was presented based on the biomimesis. GFP, viologen, and cytochrome c was used as an electron sensitizer, a mediator, and an electron acceptor. Cytochrome c molecules and viologen molecules were deposited by Langmuir-Blodgett (LB) technique, and GFP molecules were adsorbed by self-assembly method (SAM). Surface morphology of hetero-thin film was analyzed by scanning tunneling microscopy (STM). Local photoswitching effects of a proposed photodiode were verified by current-voltage measurements using hybrid STM/I-V measurement system.

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Ultra-thin Film Assembly of a Novel Biomaterial Containing Protein and Functionalized Polymer for Sensor Application

  • Lim, Jeong-Ok;Sohn, Byung-Ki;Huh, Jeung-Soo
    • Journal of Sensor Science and Technology
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    • v.4 no.4
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    • pp.81-87
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    • 1995
  • A novel biomaterial capable of incorporating biotinylated biomolecule has been synthesized. Our strategy is to biotinylate one-dimensional electroactive polymers and use a bridging streptavidin protein on Langmuir-Blodgett (LB) organized films. These copolymers are derivatized with long alkyl chains and biotin moieties to bind, respectively, to the hydrophobic surface and the biotinylated species, through the biotin and streptavidin complexation. We utilize the polymer assembly approach to attach a signal transducing biomolecule biotinylated phycoerythrin (B-PE) into this novel biomaterial by binding the unoccupied biotin binding sites on the bound streptavidin (4 sites total). The pressure-area isotherm of the protein injected monolayer showed area expansion. A characteristic fluorescent emission peak at 576nm was detected from the monolayer transferred onto a solid substrate. These observations demonstrated the promise of the organized thin polymer assemblies for their application to the sensor system.

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A Simulation of the Dipole Moments in Monolayer of Lipids on a Water Surface (수면상(水面上) 단분자(單分子) 계질막(階質膜)에서 쌍극자 모멘트의 시뮬레이션)

  • Lee, Won-Jae;Choi, Myung-Ku;Kim, Sang-Keol;Lee, Ho-Sik;Kim, Tae-Wan;Kang, Dou-Yol
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.04b
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    • pp.160-163
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    • 2000
  • Monolayers of lipids on a water surface have attracted much interest as models of biological membranes. but also as precursors of multilayer systems promising many technical applications. They exhibit very interesting physico-chemical properties as two-dimensional and interfacial systems. Until now. many potential methodologies have been developed in order to gain a better understanding of the relationship between the structure and function of the monolayers.

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Structural Characteristics of Fatty Acid Thin films (지방산계 박막의 구조 특성)

  • Jung, You-Ra;Choi, Yong-Sung;Hwang, Yong-Sun;Lee, Kyung-Sup
    • Proceedings of the KIEE Conference
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    • 2009.04a
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    • pp.33-36
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    • 2009
  • In this paper, evaluation of physical properties was made for dielectric relaxation phenomena by the detection of the surface pressures and displacements current on the monolayer films of fatty acid monomolecular Arachidic Acid, Stearic Acid using compressing velocity. LB(Langmuir-Blodgett) thin films were manufacture by detecting deposition for the accumulation and the current was measured after the electric bias was applied across the manufactured MIM device. The physicochemical properties of the fatty acid monomolecular Arachidic Acid, Stearic Acid films surface structure has been studied by AFM. We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is gas state, liquid state, solid state. Formation that prevent when gas phase state and liquid phase state measure but could know organic matter that molecules form equal and stable film when molecules were not distributed evenly, and accumulated in solid state only.

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A Study on the Light Stimulated Transmit of Organic Monolayers (유기 한분자학의 광자극 전달에 관한 연구)

  • 강용철;권영수;조수영;박석순;이경섭
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.11a
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    • pp.156-159
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    • 1996
  • Detection of displacement current across spreading organic Azodyes was investigated using a displacement current measuring technique. It was found that displacement current was generated only when dynamical motion of organic monolayers was initiated on the water surface by photo-isomerization and application of surface pressure. Displacement current was generated only in the range before the initial rise of Surface pressures for azo dyes(8A5H) we are using the Langmuir-Blodgett(LB) films deposition apparatus. We are obtain displacement current by pressure and light

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Study on Electrical Phenomena Properties of Bio-lipid Film on Water Surface for Application of Medical Engineering Device (의용 소자로의 응용을 위한 생체 지질막의 수면상에서의 전기적 현상 특성 연구)

  • Lee, Ho-Shik;Kang, Hyen-Wook;Jang, Kyung-Uk;Kwon, Young-Soo;Kim, Tae-Wan;Iwamoto, M.;Lee, Won-Jae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.11
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    • pp.1029-1032
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    • 2006
  • Monolayers of lipids on a water surface have attracted much interest as models of biological membranes, but also as precursors of multilayer systems promising many technical applications. They exhibit very interesting physico-chemical properties as two-dimensional and interfacial systems. Until now, many potential methodologies have been developed in order to gain a better understanding of the relationship between the structure and function of the monolayers.

A study on the NO$_2$ gas detector development using the CuTBP (Copper-tetra-te rt-butylphthalocyanine) chemiresistor device (CuTBP(Copper-tetra-tert-butylphthalocyanine) 화학 저항 장치를 이용한 NO$_2$ 가스 탐지기의 개발에 관한 연구)

  • 구자룡;이창희;김태완;김정수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.11a
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    • pp.417-420
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    • 1996
  • We have investigated air/200ppm NO$_2$ gas-detector characteristics of using CuTBP (Copper-tetra-tert-butylphthalocyanine) chemiresistor devices. The CuTBP films were made by Langmuir-Blodgett (LB) techniques. Sensitivity, response time, recovery time, and repoducibility of the devices were measured by current-voltage characteristics. To increase sensitivity, interdigital electrode was used. It was found that a conductance G increases monotonically as the number of interdigital electrode increases, and a Sensitivity, Reproducibility is stable. As far as a current is concerned, the current when N=25 is greater than that when N=1 by 70 or so. It indicates that the number of interdigital electrodes affects the current, sensitivity and stability We have also investigated applicability of the CuTBP chemiresistor device for a gas detector.

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Deposition Transfer and Response Properties of p-PDA/AA Mixed Films (p-PDA/AA 혼합막의 누적전이와 응답특성)

  • 송진원;이경섭
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.511-514
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    • 2000
  • Photoreactive multilayer films were prepared using long-chin alkyl diesters of p-phenylenediacrylic acid(p-PDA). In spite of the absence of hydrophilic groups in these molecules, they formed stable monolayers on the water surface when mixed with arachidic acid. Surface showed the presence of a condecsed phase and these monolayer could be transferred onto a substrate with Y-type deposition. The UV spectra of mixed multilayer films showed of absorption peak compared with that in solution. The linear relationship between absorbanoe and the number of layers supports the successful formation of multilayer films.

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