• Title/Summary/Keyword: Langmuir-blodgett

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A Study on the Molecular Orientation of Po1yamic Acid Alkylamine Salt Langmuir-Blodgett Films (Polyamic Acid 알킬아민 염 랭뮤어-블로젯막의 분자 배향에 관한 연구)

  • 정순욱;임현성
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2000.11a
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    • pp.53.1-56
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    • 2000
  • Langmuir-Blodgett(LB) technique is the best candidate for the future molecular electronic devices. But, these molecular thin film devices require the bulk properties that are influenced by the molecular orientations. So, this is of current interest in molecular electronic device fabrications of new materials. In this study, quantitative evaluation of molecular orientation in LB films of PAAS was performed by comparing the absorption intensities of the FT-IR transmission and reflection-absorption spectra and the polarized UV/visible absorption spectra. It was found that the polar angle($\theta$) of the dipole moment is about 68$^{\circ}$and the tilting angle of the alkyl chain is about $11.5^{\circ}$ .

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Stability to the spreading solvent of(3-Alkyl benzimidazolium)-TCNQ(1:1) Complex for Langmuir-Blodgett Technigue (Langmuir-Blodgett법을 위한(3-Alkyl benzimidazolium)-TCNQ(1:1)착물의 분산용매 중에서의 안정성)

  • Sohn, Byoung-Chung;Hwang, Kyo-Hyun;Jeong, Soon-Wook
    • Journal of the Korean Applied Science and Technology
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    • v.11 no.1
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    • pp.39-44
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    • 1994
  • A Stability to the Spreading solvents, Which is acetonitrile, dichloromethane, benzene, chloroform and acetonitrile-benzene(1:1, v/v) of (3-Alkyl benzimidazolium)-TCNQ(1:1) Complex was investigated by UV-visible Spectrometer and was confirmed stabilized on acetonitrile, acetonitrilbenzene(1:1, v/v) for five hours. Using Ultra pure water as subphase for Langmuir-Blodgett (LB) Films, it was achived successively to fabricate the Y-type LB films of (3-Alkyl benzimidazolium)-TCNQ(1:1) Complex. For the identification of deposition of (3-Alkyl benzimidazolium)-TCNQ(1:1) Complex, UV-visible spectra was recorded on HP 8452A spectrometer.

Electrochemical properties of Langmuir-blodgett Films of Fatty acid containing Azobezene (아조벤젠기를 가진 지방산 Langmuir-blodgett막의 전기화학적 특성)

  • 박근호;김범준;손태철;이경구;주찬홍;박태곤
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.459-462
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    • 2001
  • We have investgated the photoisomerization using light irradiation 8A5H LB film accumulated by monolayer and three layers on an ITO. We determined electrochemical measurement by using cyclic voltammetry with a three-electrode system, An Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode measured in 0.1mol/L NaClO$_4$ solution. The scan rate was 100mv/s.

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$NO_2$Gas Detection Characteristics of Octa-dodecyloxy Copper-phthalocyanine Langmuir-Blodgett(LB) Films

  • Koo, Ja-Ryong;Kim, Young-Kwan;Kim, Jung-Soo
    • Electrical & Electronic Materials
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    • v.11 no.10
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    • pp.78-80
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    • 1998
  • Metallo-phthalocyanines(MPcs) are very sensitive to toxic molecules such as electron affinitive NO2 gas and also chemically and thermally stable since losts of MPcs have been studied for the potential chemcial gas sensors for $NO_2$ using their electrical conductivity. In this study, thin films of octa-dodecyloxy copper -phthalocyanine were prepared by Langmuir-Blodgett(LB) method and characterized by using UV/Vis absorption spectroscopy, and ellipsometry. It was found that the proper transfer surface pressure for the film deposition was 25mN/m and the limiting area per molecule was $112\AA$/molecule. The film thickness of one layer was $64\AA$. Current-voltage(I-V) characteristics of these films were investigated as a function of film thickness.

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Electrical and Chemical characteristics of Zn(II)-Porphyrin Langmuir-Blodgett(LB) Films (Zn(II)-Porphyrin LB막의 전기, 화학적 특성에 관한 연구)

  • Koo, Ja-Ryong;Lee, Ho-Sik;Kim, Young-Kwan;Kim, Jung-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.752-755
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    • 2002
  • Since Metallo-Porphyrin (MP) is very interesting compound due to its unique electronic and redox properties and it is also chemically and thermally stable, MP has been studied for potential memory and switching devices. In this study, thin films of 5,10,15,20 - Tetrakis - Octadecyloxymethylphenyl - Porphyrin - Zn(II) (Zn-TPP) were prepared by the Langmuir-Blodgett (LB) method and characterized by using UV/vis absorption spectroscopy and cyclic voltammetry. It was found that the proper transfer surface pressure for film deposition was 25 mN/m and the limiting area per molecule was $135{\AA}^2$/molecule. The current-voltage (I-V) characteristics of these films were investigated.

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Electrical Characteristics of Langmuir-Blodgett Ultra Thin Films (Langmuir-Blodgett 초박막의 전기적 특성)

  • You, D.S.;Kang, H.;Choi, M.K.;Jeong, S.W.;Shon, B.C.;Kang, D.Y.
    • Proceedings of the KIEE Conference
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    • 1989.07a
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    • pp.374-376
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    • 1989
  • Ultra Tihn Film of 100 angstrom-order is fabricated by Langmuir-Blodgett technique. The conductivity of this this measured by the direction of either vertical or horizontal axis is results in a quite different value. Specific inductive capacity and effect of time variation of LB films are also considered.

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Non-linear Optical Properties of the Langmuir-Blodgett Films Measured by the Differential Attenuated Total Reflection Method (미분 변조 전반사 감쇠법에 의해 측정된 Langmuir-Blodgett 박막의 비선형 광학적 성질)

  • 정미윤
    • Proceedings of the Optical Society of Korea Conference
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    • 1991.06a
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    • pp.94-97
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    • 1991
  • We have deposited the three kinds of the Langmuir-Blodgett films (Phenylhy drazone, O-stilbazene, N-stilbazene) which have optically nonlinear effect. To study the electro-optic characteristics of these LB films, we performed the differential attenuated total reflection experiment in which the optical properties of the LB films modulated by the electric field(νE = 1KHz). The surface non-linear susceptibilities $\chi$(2) of these LB films obtained, are 1.17$\times$10-10 (m/V), 36.3$\times$10-10 (m/V), and 1.62$\times$10-10 (m/V) for Phenylhydrazone, O-stilbazene, and N-stilbazene, respectively.

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Deposition condition and Confirmation of Organic Charge Transfer complex Langmuir-Blodgett Film (유기전하 이동착물 Langmuir-Blodgett막의 누적조건 및 누적확인에 관한 연구)

  • Jeong, Soon-Wook
    • Journal of the Korean Applied Science and Technology
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    • v.14 no.1
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    • pp.89-93
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    • 1997
  • In this research, ultra-thin films of organic charge transfer complex were deposited on to ordinary microscope slide-glass subtrates with a Langmuir-Blodgett technique. ${\pi}$-A isotherm characteristics of these complex were studied in order to find optimum conditions of deposition by varying temperature of subphase, compression speed, and spreading amount. Transfer ratio of these films were studied during the process of deposition. The UV-visible absorbance spectra of LB films were measured to find state of deposition by varing layer number. The observed optimum conditions of surface, pressure, spreading amount, and dipping speed for depositing LB films(Y-type) were 38m/Nm, $150{\mu}l$ and 5mm/min, respectively. Since the tansfer ratio is close to 100%, the monolayer on the subphase seems to be well transferred to the solid substrate. The thickness of the film was well-controlled as the UV-vis absorbance of films were changed linear according to the number of layers.

Stability to the Spreading Solvent of (3-Alkyl Benzumidazolium)-TCNQ(l:2) Complex for Langmuir-Blodgett Technique (Langmuir-Blodgett법을 위한(3-Alkyl benzimidazolium)-TCNQ(1:2)착물의 분산용매 중에서의 안정성)

  • Jeoung, Soon-Wook;Hwang, Kyo-Hyun;Sohn, Byoung-Chung
    • Journal of the Korean Applied Science and Technology
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    • v.11 no.2
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    • pp.99-103
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    • 1994
  • A stability to the spreading solvent, which is acetonitrile, benzene, chloroform and acetonitrile-benzene(1:1, v/v) of (3-Alkyl benzimidazdium)-TCNQ(1:2) complex was investigated by UV-visible spectrometer and was confirmed stabilized on acetonitrile, acetonitrile-benzene (1:1, v/v) for five hours. Using Ultra pure water as subphase for Langmuir-Blodgett(LB) films, it was achived successively to fabricate the Y-type LB films of (3-Alkyl benzimidazolium)-TCNQ(1:2) complex. For the identification of (3-Alkyl benzimidazolium)-TCNQ(1:2) complex, UV-visible spectra was recorded on HP 8452A spectrometer.

Stability to the Spreading Solvent of (N-docosyl Quinolinium)-TCNQ(1:2) Complex by Langmuir-Blodgett Technique (Langmuir-Blodgett법을 위한(N-docosyl quinolinium)-TCNQ(1:2)착물의 분산용매 중에서의 안전성)

  • Jeoung, Soon-Wook;Lee, Yoong-Kook;Sohn, Byoung-Chung
    • Journal of the Korean Applied Science and Technology
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    • v.11 no.2
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    • pp.93-97
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    • 1994
  • A Stability to spreading solvent, which is acetonitrile, dichloromethane, benzene, chloroform, and acetonitrile-benzene (1:1, v/v) of (N-docosyl quinolinium)-TCNQ(1:2) complex was investigated by UV-visible spectrometer and was confirmed stabilized on acetonitrile, dichloromethane, and acetonitrile-benzene(1:1, v/v) for 7 hours. Using buffer solution($ph{\doteqdot}6.0$) as subphase for Langmuir-Blodgett(LB) film, it was achieved successively to fabricate the Y type LB films of (N-docosyl quinolinium)-TCNQ(1:2) complex. For the identification of deposition of (N-docosyl quinolinium)-TCNQ(1:2) complex, UV-visible spectra was recorded on HP 8452A spectrometer.