• Title/Summary/Keyword: self-assembled

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Tuning Hydrophobicity of TiO2 Layers with Silanization and Self-assembled Nanopatterning

  • Nghia, Van Trong;Lee, Young Keun;Lee, Jaesang;Park, Jeong Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.291-291
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    • 2013
  • The wettability of TiO2 layers is controlled by forming highly ordered arrays of nanocones using nanopatterning, based on self-assembly and dry etching. Nanopatterning of TiO2 layers is achieved via formation of self-assembled monolayers of SiO2 spheres fabricated using the Langmuir-Blodgett technique, followed by dry etching. Compared to a thin film TiO2 layer, the nanopatterned TiO2 samples show a smaller static water contact angle, where the water contact angle decreases as the etching time increases, which is attributed to the Wenzel equation. When TiO2 layers are coated by 1H,1H,2H,2H-perfluorooctyltrichlorosilane, we observed the opposite behavior, exhibiting superhydrophobicity (up to contact angle of $155^{\circ}$) on the nanopatterned TiO2 layers. Self-assembled nanopatterning of the TiO2 layer may provide an advanced method for producing multifunctional transparent layers with self-cleaning properties.

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A Study on the Current-Voltage Characteristics of Self-Assembled Organic Molecules by using STM

  • Kim Seung-Un;Shin Hoon-Kyu;Kwon Young-Soo
    • KIEE International Transactions on Electrophysics and Applications
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    • v.5C no.3
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    • pp.115-118
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    • 2005
  • Currently, molecular devices are reported utilizing active self-assembled monolayers (SAMs) containing the nitro group as the active component, which has active redox centers [1]. SAMs are ordered molecular structures formed by the adsorption of an active surfactant on a solid surface. The molecules will be spontaneously oriented toward the substrate surface and form an energetically favorable ordered layer. During this process, the surface-active head group of the molecule chemically reacts with and chemisorbs onto the substrate In this paper, the electrical properties of the 4'4- di(ethynylphenyl)-2'-nitro-1-benzenethiolate was confirmed. This material is well known as a conducting molecule having possible application to molecular level negative differential resistance (NDR) device. To deposit the self-assembly monolayers onto the gold electrode, the prefabricated Au(1 l l) substrates were immersed into 0.5[mM/l] self-assembly molecule in THF solution. Then, the electrical properties and surface morphologies of 4' 4-di(ethynylphenyl)-2' -nitro-1-benzenethiolate were measured by using the ultra-high vacuum scanning tunneling microscopy (UHV-STM).

Electrochemical Properties of Self-Assembled Viologen Monolayer Using QCM (QCM을 이용한 자기조립화된 Viologen 단분자막의 전기화학적 특성 연구)

  • Ock, Jin-Young;Park, Sang-Hyun;Kim, Byoung-Sang;Shin, Hoon-Kyu;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 2003.07c
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    • pp.1520-1522
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    • 2003
  • Molecular self-assembled of surfactant viologen are of recent interest because they can from functional electrodes as well as micellar assemblies, which can be Profitably utilized for display devices, photoelectrochemical studies and electrocatalysis as electron acceptor or electron mediator. Fromherz et al studied the self-assembly of thiol and disulfide derivatives of viologens bearing long n-alkyl chains on Au electrode surface. The electrochemical behavior of self-assembled viologen monolayer has been investigated with QCM, which has been known as nano-gram order mass detector. The self-assembly process of viologen was monitored using resonant frequency (${\Delta}$F) and resonant resistance (R). The redox process of viologen was observed with resonant frequency (${\Delta}$F).

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Electrochemical Properties of Viologen Self-Assembly Monolayer Using QCM (수정진동자를 이용한 Viologen Self-Assembly 단분자막의 전기화학적 특성)

  • 옥진영;신훈규;박재철;장정수;권영수
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.6
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    • pp.496-500
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    • 2003
  • Molecular self-assembled of surfactant viologen are of recent interest because they can from functional electrodes as well as micellar assemblies, which can be profitably utilized for display devices, photoelectrochemical studies and electrocatalysis as electron acceptor or electron mediator. Fromherz et al studied the self-assembly of thiol and disulfide derivatives of viologens bearing long n-alkyl chains on Au electrode surface[1]. The electrochemical behavior of self-assembled viologen monolayer has been investigated with QCM, which has been known as nano-gram order mass detector. The self-assembly process of viologen was monitored using resonant frequency(ΔF) and resonant resistance(R). The redox process of viologen was observed with resonant frequency(ΔF).

Supramolecular Nanomaterials Derived from Self-Assembly of Dendritic Building Blocks

  • Park, Chi-Young;Lee, Sang-Wha;Lim, Ji-No;Lim, Moon-Seob;Kim, Chul-Hee
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.91-92
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    • 2006
  • The fine-tuned dendrons provide unique supramolecular self-assemblies in various environments such as in water, organic media, and solid-liquid interfaces. They form nanotubes, vesicles, thin films, columns, lamellar nanoribbons depending on the condition of self-assembly process. Unique characteristics of self-assembly of the amide dendrons are described. In addition, elucidation of the structural correlation between the building blocks and the assemblies, stabilization of assembled structure, and transformation of supramolecular assemblies by using external stimuli. Particular emphasis is placed on the formation of cyclodextrin-covered organic nanotubes derived from self-assembly of amide dendrons and their supramolecular transformation. Finally, unique biosensory characteristics of the self-assembled nanotubes will be discussed.

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Self-Assembled Monolayers(SAMs) (자기조립 단분자막)

  • 박경선;이보현;성명모
    • Polymer Science and Technology
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    • v.15 no.3
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    • pp.286-295
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    • 2004
  • 자기조립 단분자막 (self-assembled monolayers, SAMs)은 주어진 기질의 표면에 자발적으로 입혀진 규칙적으로 잘 정렬된 유기 분자막이다 (그림 1). SAMs의 제조에 이용되는 계면 활성제 분자는 그림 2에서 보여주듯이 세 개의 부분으로 이루어져 있다. 먼저 기질과 결합하는 머리 부분의 반응기, 규칙적인 분자 막 형성을 가능하게 하는 몸통 부분의 긴 알칸사슬, 그리고 분자 막의 기능을 좌우하는 꼬리 부분의 작용기로 나누어진다. 가장 간단한 작용기로는 알킬 그룹이 있으나 분자 막에 특수한 기능을 부여하기 위해서는 여러 가지 다른 그룹들 (예:NH$_2$, OH, COOH 등)이 이용되고 있다. (중략)

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