• 제목/요약/키워드: Langmuir-Blodgett Technique

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주사형 맥스웰 응력 현미경을 이용한 박막의 Nanometer-scale 이미지 (Nanometer-scale Imaging in Thin Films by Scanning Maxwell-stress Microscopy)

  • 신훈규;유승엽;권영수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 추계학술대회 논문집
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    • pp.133-136
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    • 1998
  • The scanning Maxwell-stress microscopy (SMM) is a dynamic noncontact electric force microscopy that allows simultaneous access to the electrical properties of molecular system such as surface potential, surface charge, dielectric constant and conductivity along with the topography. Here we report our recent results of its application to nanoscopic study of domain structures and electrical functionality in organic thin films prepared by the Langmuir-Blodgett technique.

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양친매성 다중층막의 전기적 도전성 및 전기적 특성 (The Electrical Conductivity and Electrochemical Characteristics of Amphiphilic Milecules Multilayer Film confined with Hetero Type)

  • 최인희;박수길;임기조;이주성
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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    • pp.269-272
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    • 1996
  • The electrochemical behavior of Ru complex and PD complex monolayer, deposited on conductive substrate by the Langmuir-Blodgett(LB) technique as monolayer and multilayer, has been studied by cyclic voltammetry. Monolayer films show stable reversible state. Atomic resolution imaging of LB highly-conductive, environmently stable organic films has been obtained by atomic force microscopy (AFM) showing their closely packed structure,

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Octadecylviologen-TCNQ LB 막의 물리적 특성 (Physical Properties of the Langmuir-Blodgett Films Layered with Octadecylviologen-TCNQ)

  • 신동명;박제상;강도열
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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    • pp.77-80
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    • 1995
  • Enhancing the electrical conductivity of the ultrathin organic films using Langmuir-Blodget technique is important step for the developement of molecular electronic device. The Octadecylviologen-TCNQ was synthesized with Octadecylviologen-Bromide an Lithium TCNQ Sine Octadecylviologen-TCNQ has two TCNQ snion radicals, the conductivity of LB film is expected to increase. The $\pi$-A isotherm showed that the limiting area was 150${\AA}$$\^$2/ molecule and the silid-like transition surface pressure was 25 mN/m. The electronic transition of the TNCNQ anion radical was observed at 400 nm. Intermolecular charge transfer absorption was observed at 600nm and 850~1050 nm which ay resulted from the TCNQ anion radical dimer formation. The electrical conductivity of the viologen -TCNQ LB film was 10$\^$-6/cm This values was 100 times higher than that of the quinolinium-TCNQ and pyridinium-TCNQ LB films.

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여러가지 도판트에 의해 도핑된 전도성 폴리아닐린 LB 박막의 제조 및 전기적 성질 (Preparation and Electrical Properties of Conductive Polyaniline Langmuir-Blodgett Thin Films Doped by Various Dopants)

  • 오세용;오병근;최정우;김형수;이희우;이원홍
    • 공업화학
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    • 제8권2호
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    • pp.172-178
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    • 1997
  • 폴리아닐린(PANI)-stearic acid(SA) 복합물의 단분자막이 공기-물 계면에서 형성되었으며, 계면활성제인 stearic acid는 PANI 단분자막의 형성을 증진시키는데 사용되었다. Langmuir-Blodgett(LB) 기법을 사용하여 약 1의 전이비와 Y형태를 갖는 균일한 PANI-SA의 다층막을 제조하였다. HCI 또는 $I_2$의 도핑에 의해 $10^{-1}{\sim}10^{-2}S/cm$의 높은 전기 전도도를 갖는 PANI-SA 복합막의 LB 필름을 얻었고, 그 값은 전형적인 PANI-HCl 착제와 비슷한 전도도를 나타냈다. 특히 $I_2$는 전자수용체/감광체/전자공여체로 구성된 MIM 분자 device에서 고분자 전극으로 사용하는데 뛰어난 안정성을 제공해 주기 때문에 가장 적합한 도판트로 밝혀졌다. PANI-SA LB 필름의 구조와 물리적 성질은 near-ir UV, FT-IR과 Cyclic voltammetry를 통해 조사하였다.

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Revealing Strong Metal Support Interaction during CO Oxidation with Metal Nanoparticle on Reducible Oxide Substrates

  • Park, Dahee;Kim, Sun Mi;Qadir, Kamran;Park, Jeong Young
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.264-264
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    • 2013
  • Strong metal-support interaction effect is an important issue in determining the catalytic ac-tivity for heterogeneous catalysis. In this study, we investigated the support effect and the role of organic capping layers of two-dimensional Pt nanocatalysts on reducible metal oxide supports under the CO oxidation. Several reducible metal oxide supports including CeO2, Nb2O5, and TiO2 thin films were prepared via sol-gel techniques. The structure, chemical state and optical property were characterized using XRD, XPS, TEM, SEM, and UV-VIS spectrometer. We found that the reducible metal oxide supports have a homogeneous thin thickness and crystalline structure after annealing at high temperature showing the different optical band gap energy. Langmuir-Blodgett technique and arc plasma deposition process were employed to ob-tain Pt nanoparticle arrays with capping and without capping layers, respectively on the oxide support to assess the role of the supports and capping layers on the catalytic activity of Pt catalysts under the CO oxidation. The catalytic performance of CO oxidation over Pt supported on metal oxide thin films under oxidizing reaction conditions (40 Torr CO and 100 Torr O2) was tested. The results show that the catalytic activity significantly depends on the metal oxide support and organic capping layers of Pt nanoparticles, revealing the strong metal-support interaction on these nanocatalysts systems.

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Interaction of a Pyridyl-Terminated Carbosiloxane Dendrimer with Metal Ions at the Air-Water Interface

  • Lee, Burm-Jong;Kim, Seong-Hoon;Kim, Chung-kyun;Shin, Hoon-Kyu;Kwon, Young-Soo
    • KIEE International Transactions on Electrophysics and Applications
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    • 제3C권6호
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    • pp.216-219
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    • 2003
  • A new class of carbosiloxane dendrimer (G4-48PyP) terminated with 4-pyridylpropano I was synthesized and its possible application to functional thin films was examined through metal complexation and Langmuir-Blodgett (LB) technique. The highly concentrated periphery pyridyl groups of G4-48PyP were exposed on aq. aluminum ions at the air-water interface. The monolayers showed stability up to ca. 50 mN/m of surface pressure. When the subphase became acidic or alkaline, the monolayers changed to condensed phase. The presence of aluminum ions also caused reduction of the molecular area. The macroscopic images of the monolayers were monitored by Brewster angle microscopy (BAM) and only the images of dendrimer aggregates could be observed after the monolayer collapse. The surface images of the monolayer LB film were scanned by atomic force microscopy (AFM). The convex structures of single and aggregate molecules were directly observed. The structures of Langmuir-Blodgett (LB) films were characterized by FT-IR, UV-Vis, and X-ray photoelectron spectroscopy (XPS). The UV-Vis spectrum of the aluminum ion-complexed LB film showed additional band around 670nm, which was not found in the spectra of dendrimer itself or aq. aluminum ions. XPS spectra also supported the incorporation of aluminum ions into the LB films.

스쿠알렌 집합체의 광전기화학적 효과에 관한 연구 (A Study of the Photoelectrochemical Effects of Squaraine Aggregate in Monolayer)

  • 김영순
    • 대한화학회지
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    • 제37권7호
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    • pp.642-647
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    • 1993
  • 순수 정제한 스쿠알렌 색소(DSSQ(4-distearylamino phenyl-4'-dimethylaminophenylsquaraine) 를 Langmuir Blodgett 방법으로 $SnO_2$ 전극위에 단분자막으로 도포하였다. DSSQ 용액의 최대 흡수 파장은 630 nm 이었으나, $SnO_2$ 전극에 도포한 상태는 최대흡광파장 위치가 530 nm로 이동되어 스쿠알렌 집합체를 나타내었다. 이 집합체를 열처리하였더니 최대흡광 위치는 620~680 nm 로 이동되었다. 스쿠알렌 집합체에서의 에너지 이동 관계를 알기 위하여 광전류를 측정하였다. 광전류의 action spectrum은 흡수스펙트럼과 거의 같은 경향을 보였으며, 열처리한 시료의 광전류 action 스펙트럼도 처리전과 같은 결과를 나타내었다. 이때의 양자수율은 약 0.3%이었다. 용액내의 빛의 tunneling 효과를 보기 위하여 $SnO_2$전극과 DSSQ 색소사이에 스테아린산을 2~8층으로 각각 도포하고 광전류를 측정하였더니, 광전류가 현저히 감소하였다. 2층을 더 도포한 시료에서는 광전류가 전혀 나타나지 않았다. 또한 전해질 용액에 질소를 통하였을 경우에는 광기전력이 현저히 감소하고, 산소를 통하였을 때는 같은 정도로 증가하는 것으로 보아 전해질의 용존 산소가 전자 주게 역할을 하고 있음을 추정할 수 있었다.

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Octa-dodecyloxy Copper-Phthalocyanine LB막 제작에 관한 연구 (A study on the preparation and characterization of Octa-dodecyloxy Copper-Phthalocyanine LB films)

  • 구자룡;이한성;김영관;손병청;김정수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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    • pp.150-153
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    • 1997
  • Langmuir-Blodgett(LB) technique is one of the ways of fabricating organic ultra-thin films. It is well known that It has the advantage to control the alignment and orientation of the molecules in the films. Metallo-phthalocyanines(MPcs) are sensitive to electron affinitive toxic gaseous molecules, such as NO$_2$, NO, SO$_2$. MPcs are thermal, optical, mechanical, chemical stable. Therefore, it is interesting to prepare phthalocyanine LB films containing copper as a chemical sensor for NO$_2$ and SO$_2$ gas and test their sensitivity to these toxic gases. In this study, thin films of Octa-dodecylosy copper-phthalocyanine were prepared by LB technique. $\pi$-A isotherm, transfer ratio, UV-VIS. spectroscopy of these films were investigated. Also current-voltage(I-V) characteristics of these was auto investigated.

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Octa-dodecyloxy Tin-Phthalocyanine LB막 제작에 관한 연구 (A study on the preparation and characterization Octa-dodecyloxy Tin-Phthaucyanine LB films)

  • 이명호;신현만;김영관;손병청;김정수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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    • pp.146-149
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    • 1997
  • It is well known that the metallo-phthalocyanines(MPcs) are sensitive to toxic gaseous molecules, such as NO$_2$, NO, SO$_2$. MPcs are thermally, optica1ly, mechanically and chemically stable. Therefore, it is interesting to prepare phthalocyanine LB films containing tin as a chemical sensor for NO$_2$ and SO$_2$ gas and test their sensitivity to these toxic gases. Frist, in this study, ultra thin films of Octa-dodecyloxy tin-phthalocyanine were prepared on various substrates by LB technique. Langmuir-Blodgett(LB) technique is one of the ways of fabricating organic thin films. It has the advantage to control the alignment and orientation of the molecules in the films. $\pi$-A isotherm and transfer ratio of tin-phthalocyanine derivative. UV-VIS. spectroscopy were investigated. Also intrinsic current-voltage(1-V) characteristics of these films was investigated.

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Soft-Lithographic Fabrication of Ni Nanodots Using Self-Assembled Surface Micelles

  • Seo, Young-Soo;Lee, Jung-Soo;Lee, Kyung-Il;Kim, Tae-Wan
    • Journal of Magnetics
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    • 제13권2호
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    • pp.53-56
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    • 2008
  • This study proposes a simple nano-patterning process for the fabrication of magnetic nanodot arrays on a large area substrate. Ni nanodots were fabricated on a large area (4 inches in diameter) Si substrate using the soft lithographic technique using self-assembled surface micelles of Polystyrene-block-Poly(methyl methacrylate) (PS-b-PMMA) diblock copolymer formed at the air/water interface as a mask. The hexagonal array of micelles was successfully transferred to a Ni thin film on a Si substrate using the Langmuir-Blodgett technique. After ion-mill dry etching, a magnetic Ni nanodot array with a regular hexagon array structure was obtained. The Ni nanodot array showed in-plane easy axis magnetization and typical soft magnetic properties.