• 제목/요약/키워드: SAMs

검색결과 177건 처리시간 0.021초

유기 자기조립 단분자막의 레이저 포토 패터닝을 이용한 박막 미세 형상 가공 기술 (Micromachining Thin Film Using Femtosecond Laser Photo Patterning Of Organic Self-Assembled Monolayers.)

  • 최무진;장원석;김재구;조성학;황경현
    • 한국정밀공학회지
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    • 제21권12호
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    • pp.160-166
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    • 2004
  • Self-Assembled Monolayers(SAMs) by alkanethiol adsorption to thin metal film are widely being investigated fer applications as coating layer for anti-stiction or friction reduction and in fabrication of micro structure of molecule and bio molecule. Recently, there have been many researches on micro patterning using the advantages of very thin thickness and etching resistance of Self-Assembled Monolayers in selective etching of thin metal film. In this report, we present the several machining method to form the nanoscale structure by Mask-Less laser patterning using alknanethiolate Self-Assembled Monolayers such as thin metal film etching and heterogeneous SAMs structure formation.

Nano-identification for the Cleavage of Disulfide Bond during the Self-Assembly Processes of Unsymmetric Dialkyl Disulfides on Au(111)

  • Noh, Jae-Geun
    • Bulletin of the Korean Chemical Society
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    • 제26권4호
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    • pp.553-557
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    • 2005
  • The formation of striped phases of unsymmetric hexyl octadecyl disulfide ($CH_3(CH_2)_5SS(CH_2)_{17}CH_3$, HOD) and 1-hydroxyundecyl octadecyl disulfide ($CH_3(CH_2)_{17}SS(CH_2)_{11}$OH, HUOD) on Au(111) and graphite has been investigated by scanning tunneling microscopy (STM) to understand the self-assembly processes of dialkyl disulfides. STM imaging clearly shows the formation of striped phases having corrugation periodicities that are nearly consistent with the molecular length of alkanethiolate moieties formed after the S-S bond cleavage of dialkyl disulfide on a gold surface. On the other hand, self-assembled monolayers (SAMs) of dialkyl disulfides on a graphite surface displayed long-range, well-ordered monolayers with one striped pattern that shows periodicity as a function of molecular length via nondissociative adsorption. From a nonoscopic viewpoint, we have clearly demonstrated that dialkyl disulfide SAMs on gold form via S-S bond cleavage of disulfide.

SAMs of 2-Aminoethanethiol Modified with 3,4-Dihydroxyphenylalanine for the Electrocatalytic Oxidation of NADH on Gold Electrodes

  • Cha, Seong-Keuck
    • Bulletin of the Korean Chemical Society
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    • 제25권6호
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    • pp.786-790
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    • 2004
  • 2-Aminoethanethiol (aet) has been used to make self-assembled monolayer (SAMs) on gold electrodes, which are subsequently modified with 3,4-dihydroxy phenylalanine (dpa). Such modified electrodes having various types of Au/aet-dpa were employed in the electrocatalytic oxidation of NADH. The purpose of this study to characterize the responses of such modified electrodes in terms of the immobilization procedure, pH of the solution and applied potential. The reaction of the surface immobilized dpa with NADH was studied using the rotating disk electrode technique and a value of $2.2{\times}10^4M^{-1}s^{-1}$ was obtained for the second-order rate constant in 0.1 M Tris/$NO_3^-$buffer (pH=8.0). The hydration behavior of the films was characterized by quartz crystal microbalance. When used as a NADH sensor, the Au/aet-dpa electrode exhibited good sensitivity and an excellent correlation (r ${\geq}$ 0.99) for NADH concentration which extended to $3.8{\times}10^{-3}$ M.

Characterization of biotin-avidin recognition system constructed on the solid substrate

  • Lim, Jung-Hyurk
    • 분석과학
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    • 제18권6호
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    • pp.460-468
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    • 2005
  • The biotin-avidin complex, as a model recognition system, has been constructed through N-hydroxysuccinimide(NHS) reaction on a variety of substrates such as a smooth Au film, electrochemically roughened Au electrode and chemically modified mica. Stepwise self-assembled monolayers (SAMs) of biotin-avidin system were characterized by surface-enhanced resonance Raman scattering (SERRS) spectroscopy, atomic force microscopy (AFM) and surface plasmon resonance (SPR). A strong SERRS signal of rhodamine tags labeled in avidin from the SAMs on a roughened gold electrode indicated the successful complex formation of stepwise biotin-avidin recognition system. AFM images showed the circular shaped avidin aggregates (hexamer) with ca. $60{\AA}$ thick on the substrate, corresponding to one layer of avidin. The surface coverage and concentration of avidin molecules were estimated to be 90% and $7.5{\times}10^{-12}mol/cm^2$, respectively. SPR technique allowed one to monitor the surface reaction of the specific recognition with high sensitivity and precision.

게이트 절연막에 OTS를 처리한 후 활성층 Pentacene 성장에 따른 OTFT 전기적 특성 (After treated the OTS of the gate insulator, the OTFT electric property of active layer Pentacene growth)

  • 손재구;오데레사;김홍배
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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    • pp.238-239
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    • 2006
  • 본 논문은 게이트 절연막에 OTS(n-octadecy trichlorosilance) 혼합용액을 이용하여 SAMs(Self-Assembled Monolayers)막을 형성하였다. OTS 혼합용액은 OTS를 0.1w%와 0.5w% 각각을 클로로포름 30w%와 헥산 70w%에 혼합하여 만들었다. 이 혼합용액을 게이트 절연막위에 표면처리하였다. 활성층인 Pentacene이 게이트 절연막 위에 증착될 때, OTS 혼합용액의 비에 따라 누설전류특성을 보았다. OTS를 0.1w% 처리한것이 0.5w%보다 누설전류가 더 작게 나타났다. 결과적으로 OTFT의 게이트 절연막의 절열특성은 향상시키는데 OTS 혼합용액의 비가 큰 영향을 준다.

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Self-Assembled Monolayers of Alkanethiols on Clean Copper Surfaces

  • ;김연수
    • Bulletin of the Korean Chemical Society
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    • 제22권7호
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    • pp.748-752
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    • 2001
  • Alkanethiols (CH3(CH2)n-1SH) based self-assembled monolayers (SAMs) on the clean copper surfaces have been examined for n = 4, 8, and 16. Using X-ray photoelectron spectroscopy (XPS) and contact angle analysis, it is found that alkanethiolate monolayers similar to those on gold are formed on clean copper surfaces. The monolayers are stable in air up to about 140 $^{\circ}C.$ Above 160 $^{\circ}C$ the monolayers begin to desorb through the oxidation reaction of the thiolate to sulfonate, with the alkyl chains remaining intact. Following this desorption step, the copper surface has begun to oxidize to CuO at about 180 $^{\circ}C$.

Electrochemical Properties of Electroactive Monolayers Having $[Os(bpy)_3]^{2+}$ Moieties

  • 방경숙;전일철
    • Bulletin of the Korean Chemical Society
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    • 제22권3호
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    • pp.281-287
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    • 2001
  • Self-assembled monolayers (SAMs) of the alkylthiols with [Os(bpy)3]2+ moiety at the terminal position were prepared on gold electrode surface. Examination of the cyclic voltammograms for the SAM shows that it does not organiz e well unlike alkylthiols, which is attributed to the much larger diameter of [Os(bpy)3]2+ moiety compared with the cross-section of alkyl chains and the distance between the adsorption sites. Electromicrogravimetry study shows that the hydration numbers of the electrolyte were 16 $\pm2$, 11 $\pm1$, 5 $\pm$ 1 and 24 $\pm6$ for ClO4- , PF6-, NO3- , and SO42- , respectively. The binary SAMs of alkylthiols with [Os(bpy)3]2+ terminal-group were prepared by co-adsorption of alkylthiols as spacer molecules, which results in better packing in SAM and accordingly the stability was enhanced.

Unusual Applications of Kendrick Plots: Recalibration and Tolerance

  • Thierry N. J. Fouquet;Orlando Cabarcos
    • Mass Spectrometry Letters
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    • 제14권4호
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    • pp.173-177
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    • 2023
  • Kendrick plots offer an alternative visualization of mass spectral data which reveals ion series and patterning by turning a mass spectrum into a map, plotting the fractional mass (wrongly called mass defect) as a function of mass-to-charge ratios and ion abundances. Although routinely used for polymer mass spectrometry, two unreported applications of these Kendrick plots are proposed using the program "kendo2": the graphical recalibration of a mass spectrum via the simulation of a theoretical fractional mass and a multi-segment fit; and the rapid evaluation of scan-to-scan variation of accurate mass measurements used as tolerances for the blank subtraction of UPLC-MS data files. Both applications are compatible with any type of high-resolution MS data including LC/GC-MS(/MS).