• Title/Summary/Keyword: $\pi$-A isotherm

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Electrical Properties of LB Films by Using IMI-O Polymer (IMI-O고분자 LB막의 전기적 특성)

  • 정상범;유승엽;박재철;이범종;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.202-205
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    • 1997
  • In this paper, we synthesized poly(N-(2-4-imidazolyl) ethyl) maleimide-alt-1-octadecene(IMI-O) polymer that can have function group and improvement of mechnical strength and then confirmed the possibility of molecular device made by LB method. Evaluation of LB film have been processed such as the technique of EA, $^{1}$H-NMR, FT-IR. Also, the deposition status was observed by SEM and Metal/Insulator/Metal(MIM) device was fabricated for investigation of electric properties. In our experimental results. The surface pressure for the solid state was investigated to 20~35[dyne/cm] by the $\pi$ -A isotherm and the limiting area was about 40 ~45 ($\AA$$^2$/molecule). The deposition status of LB films was confirmed by SEM. The conductivity of LB film was found to be 10$^{-14}$ ~10$^{-13}$ [S/cm] by I-V characteristic.

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The Deposition Characterization of DLPC Lipid Membrane by Moving Wall Type LB Methode (Moving Wall형 LB법에 의해서 제작된 DLPC 지질막의 누적특성)

  • 정용호;이우선;김남오;이경섭
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.342-345
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    • 1997
  • We fabricated the sample of u1tra thin lipid membrane(L-${\alpha}$-DLPC ) by LB methode. The $\pi$-A isotherm of the DLPC was measured at the air-water interface varying with the compressing speed and amounts of solutions for spreading. For good property of lipid monolayer film, it was necessary for the lower speed of compressing, and 40${\mu}\ell$ of solutions for spreading. The molecular arrangement of deposited films were evaluated by measuring the absorption, transmitance and intensity with the UV spectrophotometer. The Y-type multilayers prepared at 50mN/m showed weaker than Z-type. So we found building-up of structurally high quality LB films is essential to study properties of the films and to get reproducible data.

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Deposition condition, Cinfirmation, and electrical properties of ${C_22}$-quinolium(TCNQ) langmuir-blodgett films (박막의 누적조건, 누적확인 및 전기적인 특성)

  • 김태완;박승규;홍언식;홍진표;강도열
    • Electrical & Electronic Materials
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    • v.5 no.4
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    • pp.411-420
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    • 1992
  • C$_{2+}$-Quinolium(TCNQ) 유기 초박막을 Langmuir-Blodgett 방법을 이용하여 유리기판 위에 누적하였다. 이의 최적 누적조건을 알아보기 위하여 .pi.-A isotherm특성을 온도, pH, 압축 속도, 분산량 등을 변화시키면서 조사하였다. 누적 과정은 전이비를 통하여 고체 기판에 누적되는 정도를 살펴볼 수 있었으며 누적된 박막은 다음과 같은 방법으로 확인하였다. 광학적인 방법으로 광흡수도, 전기적인 방법으로 전기 용량, 그리고 기계적인 방법으로 두께를 직접 측정하여 누적된 박막의 상태를 관찰하였다. 상온에서 이방성 전기 전도도를 측정하였는데 수평 방향으로 ~1 x $10^{-7}$S/cm, 수직 방향으로 ~1 x $10^{-14}$S/cm의 값을 얻었다.

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Studies on synthesis of Charge Transfer Complex and Preparation Characteristics of its LB Films (전하이동착체의 합성과 Langmuir-Blodgett막의 제조에 관한 연구)

  • Sohn, Mi-Wha;Sohn, Byoung-Chung
    • Journal of the Korean Applied Science and Technology
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    • v.12 no.2
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    • pp.137-143
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    • 1995
  • Octadecyltrimethylammonium-TCNQ(1:1) complex was synthesized by the reaction of LiTCNQ with octadecyltrimethylammonium bromide and the reaction product was identified with FT-IR and UV/Vis spectroscopies. In order to prepare the LB films, ${\pi}-A$ isotherm characteristics of octadecyltrimethylammonium-TCNQ(1:1) complex were investigated. The LB films of octadecyltrimethylammonium-TCNQ(1:1) complex were formed on various substrates and the formation of ultrathin films of octadecyltrimethylammonium-TCNQ(1:1) complex was confirmed by using FT-IR and UV-Vis spectroscopies.

Electrical Properties of IMI-O Polymeric LB Films Using logic Concentration (이온농도에 의한 IMI-O고분자 LB막의 전기특성)

  • 정상범;유승엽;박재철;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.418-420
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    • 1997
  • We synthesized the polymer that can have function group and improvement of mechnical strength and then confirmed the possibility of molecular device made by LB method. In this paper, the $\pi$-A isotherm has been investigated as to the kinds and various concentrations of the metal ions complexed with imidazole group. The experimental results for the electrical properties of MIM fabricated has been obtained as following. There is no change in limiting area as to the kinds of the metal ions, also the shift of conductivity as to the metal ions couldn't be observed, which was 10$\^$-14/[S/cm]. There are some changes in limiting area as to the concentration of the metal ions, the conductivity shift was increased with the occupied molecular area.

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The Deposition Characterization of DLPC Lipid Membrane Fabricated by Moving wall Type LB Method (Moving wall형 LB법에 의하여 제작된 DLPC 지질막의 누적특성)

  • 이우선;최창주;정용호;김남오;이경섭;장의구;김태성
    • Electrical & Electronic Materials
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    • v.10 no.6
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    • pp.548-554
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    • 1997
  • We fabricated the sample of ultra thin lipid membrane(L-$\alpha$-DLPC) by LB method. The $\pi$-A isotherm of the DLPC was measured at the air-water interface varying with the compressing speed and amounts of solutions for spreading. For the good property of lipid monolayer film, it was necessary to prepare at the lower speed of compressing, with an appropriate volume of solutions for spreading. Absorption, transmitance and intensity with the UV spectrophotometer were measured. The Z-type multilayers showed good characteristics better than Y-type. So we found building-up of structurally high quality LB films is essential to study properties of the films and to get reproducible data.

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Fabrication as Ultra-thin films of Amphiphilic Squarylium dye by the Langmuir-Blodgett Technique (랭뮤어-블로젯법에 의한 양친매성 스쿠아릴리움 색소의 초박막 제작)

  • Jeong, Sun-Uk
    • Korean Journal of Materials Research
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    • v.9 no.6
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    • pp.595-598
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    • 1999
  • Ultra-thin films of amphiphilic Squarylium dye were prepared on the hydrophilic glass substrate by Langumuir-Blodgett(LB) technique. From the measurement of the surface pressure-area($\pi$-A) isotherm at air-water interface, it was found that amphiphilic Squarylium dye can form the stable monolayers. Using the LB technique, the Z-type monolayer assembly can be obtained. The amphiphilic Squarylium dye LB films exhibit λ\ulcorner at 684nm. The absorption is significantly red-shifted from solution of amphiphilic Squarylium dye(637nm in chloroform), suggesting that the Squarylim chromophores form J-aggregate in the LB film.

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An influence on EDC/PPCPs adsorption onto single-walled carbon nanotubes with cationic surfactant (단일벽 탄소나노튜브의 미량유해물질 흡착거동에서 양이온 계면활성제의 영향에 관한 연구)

  • Heo, Jiyong;Lee, Heebum;Han, Jonghun;Son, Mihyang;Her, Namguk
    • Journal of Korean Society of Water and Wastewater
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    • v.28 no.4
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    • pp.419-429
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    • 2014
  • Recent studies have been reported the presence of Endocrine Disrupting Compounds, Pharmaceuticals and Personal Care Products (EDC/PPCPs) in surface and wastewater, which could potentially affect to the complicate behavior in coupled presence of nano-colloid particles and surfactants (adsorption, dispersion, and partitioning). In this study, the adsorption of EDC/PPCPs by Single Walled Carbon Nanotubes (SWNTs) as a representative of nano-particles in cationic surfactant solutions were investigated. Hydrophobic interactions (${\pi}-{\pi}$ Electron Donor-Acceptor) have been reported as a potential adsorption mechanisms for EDC/PPCPs onto SWNTs. Generally, the adsorptive capacity of the relatively hydrophobic EDC/PPCPs onto SWNTs decreased in the presence of cationic surfactant (Cetyltrimethyl Ammonium Bromide, CTAB). This study revealed that the competitive adsorption occurred between CTAB cations and EDC/PPCPs by occupying the available SWNT surface (CTAB adsorption onto SWNTs shows five-regime and maximum adsorption capacity of 370.4 mg/g by applying the BET isotherm). The adsorption capacity of $17{\alpha}$-ethinyl estradiol (EE2) on SWNT showed the decrease of 48% in the presence of CTAB. However, the adsorbed naproxen (NAP) surely increased by forming hemimicelles and resulted in a favorable media formation for NAP partition to increase SWNTs adsorption capacity. The adsorbed NAP increased from 24 to 82.9 mg/g after the interaction of CTAB with NAP. The competitive adsorption for EDC/PPCPs onto SWNTs is likely to be a key factor in the presence of cationic surfactant, however, NAP adsorption showed a slight competition through $CH_3-CH_3$ interaction by forming hemimicelles on SWNT surface.

A study on the deposition conditions and physical properties of the Hexadecyl Dipyridinium-$(TCNQ^-)_2$ thin films with Langmuir-Blodgett technique (LB법을 이용한 Hexadecyl Dipyridinium-$(TCNQ^-)_2$의 박막 제작과 물리적 특성 연구)

  • Lee, Yong-Soo;Shin, Dong-Myung;Kim, Tae-Wan;Kang, Dou-Yol
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1722-1724
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    • 1996
  • 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 as out of the ways of deposition ultrathin films. We have studied manufacturing conditions and physical properties of Hexadecyl Dipyridinium-$(TCNQ^-)_2$ LB films made by Kuhn type apparatus. A ${\pi}-A$ isotherm shows that a limiting area is around $180{\AA}^2/molecule$ and a proper surface pressure for a deposition is around 22mN/m. A transfer ratio shows that Hexadecyl Dipyridinium-$(TCNQ^-)_2$ is able to be deposited as an Y-type. UV /visible absorption spectra shows that TCNQ dimer peak is apeared at about 600nm in LB films. In solution, $TCNQ^-$ peak is observed at about 400nm and charge transfer band at $830{\sim}900nm$. A horizontal conductivity of the Hexadecyl Dipyridinium-$(TCNQ^-)_2$ LB film is about $10^{-7}(S/cm)$.

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Study on synthesis of Schiff base and its basic characteristics (Schiff base의 합성과 그의 기초적 물성에 관한 연구)

  • Shin, Dong-Gyu;Kwon, Oh-Kwan;Lim, Sung-Taek;Kim, Young-Kwan;Nam, Ki-Dae;Sohn, Byoung-Chung
    • Journal of the Korean Applied Science and Technology
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    • v.15 no.4
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    • pp.57-62
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    • 1998
  • In this study, a new conducting materials, namely, a Schiff base (polymeric azomethine) was synthesized from 2,6-diamino-N-docosyl pyridinium bromide and terephthalaldehyde to obtain a soluble and fusible conducting polymer. The synthesized Schiff base structure was analyzed by using UV/vis absorption spectrophotometer, FT-IR spectrometer and $^1H$-NMR spectrometer. It was found that the Schiff base was successfully synthesized and soluble in carbon tetrachloride$(CC^{14})$, its Langmuir-Blodgett film was easily fabricated, and its surface pressure was determined to be 30mN/m for solid state by measuring ${\pi}$-A isotherm.