Alkanethiol

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Anne L. Plant - One of the best experts on this subject based on the ideXlab platform.

  • Effect of an Oxidized Gold Substrate on Alkanethiol Self-Assembly
    Langmuir, 2000
    Co-Authors: John T. Woodward, Curtis W. Meuse, Marlon L. Walker, David J. Vanderah, G. E. Poirier, Anne L. Plant
    Abstract:

    UV-cleaned gold substrates incubated in solutions of Alkanethiol show islands on the monolayer surface when imaged with noncontact atomic force microscopy (AFM). The height of the islands above the monolayer is approximately twice the height of the Alkanethiol monolayer, and the diameter of the islands is 20-200 nm. These islands are easily pushed aside during contact mode AFM imaging without damaging the underlying monolayer. Islands are observed on gold substrates exposed to solutions of octadecane-, hexadecane-, and dodecanethiol and 1′-thiahexa(ethylene oxide)-1-octadecane at 0.01-1.0 mM concentrations in ethanol and hexadecane. AFM on samples with submonolayer coverage shows that the islands are not observed until the late stages of monolayer formation. Islands are not observed on freshly deposited gold substrates or on UV-cleaned gold substrates that are exposed to ethanol for longer than 10 min prior to incubation in Alkanethiol solutions. We conclude that the island formation is associated with oxidation of the gold surface and that the islands are primarily composed of Alkanethiol. We hypothesize that the stability of these structures may be due to the formation of multimolecular complexes of Alkanethiols.

  • Assessing the Molecular Structure of Alkanethiol Monolayers in Hybrid Bilayer Membranes with Vibrational Spectroscopies
    Langmuir, 1998
    Co-Authors: Curtis W. Meuse, Gediminas Niaura, Mary L. Lewis, Anne L. Plant
    Abstract:

    Hybrid bilayer membranes (HBMs), consisting of a lipid monolayer covering a self-assembled Alkanethiol monolayer on a metal surface, are useful models for studying the structure and function of cell membranes. Surface-enhanced Raman spectroscopy (SERS) and reflection absorption infrared spectroscopy (RAIRS) are used to study HBMs with various Alkanethiol and lipid components. Together, these two techniques clearly indicate that the lipid forms a well-ordered, non-interdigitated layer on the Alkanethiol with the head groups of the lipids oriented away from the metal surface. Both techniques reveal that the formation of an HBM produces small changes in the Alkanethiols, which are similar to those caused by a reduction in temperature, indicative of an increase in order. The small magnitude of the perturbations in the Alkanethiol monolayer upon addition of the lipid layer will simplify the further study of HBMs.

  • supported phospholipid Alkanethiol biomimetic membranes insulating properties
    Biophysical Journal, 1994
    Co-Authors: Anne L. Plant, M. Gueguetchkeri, W. Yap
    Abstract:

    A novel model lipid bilayer membrane is prepared by the addition of phospholipid vesicles to Alkanethiol monolayers on gold. This supported hybrid bilayer membrane is rugged, easily and reproducibly prepared in the absence of organic solvent, and is stable for very long periods of time. We have characterized the insulating characteristics of this membrane by examining the rate of electron transfer and by impedance spectroscopy. Supported hybrid bilayers formed from phospholipids and Alkanethiols are pinhole-free and demonstrate measured values of conductivity and resistivity which are within an order of magnitude of that reported for black lipid membranes. Capacitance values suggest a dielectric constant of 2.7 for phospholipid membranes in the absence of organic solvent. The protein toxin, melittin, destroys the insulating capability of the phospholipid layer without significantly altering the bilayer structure. This model membrane will allow the assessment of the effect of lipid membrane perturbants on the insulating properties of natural lipid membranes.

  • Supported phospholipid/Alkanethiol biomimetic membranes: insulating properties
    Biophysical journal, 1994
    Co-Authors: Anne L. Plant, M. Gueguetchkeri, W. Yap
    Abstract:

    A novel model lipid bilayer membrane is prepared by the addition of phospholipid vesicles to Alkanethiol monolayers on gold. This supported hybrid bilayer membrane is rugged, easily and reproducibly prepared in the absence of organic solvent, and is stable for very long periods of time. We have characterized the insulating characteristics of this membrane by examining the rate of electron transfer and by impedance spectroscopy. Supported hybrid bilayers formed from phospholipids and Alkanethiols are pinhole-free and demonstrate measured values of conductivity and resistivity which are within an order of magnitude of that reported for black lipid membranes. Capacitance values suggest a dielectric constant of 2.7 for phospholipid membranes in the absence of organic solvent. The protein toxin, melittin, destroys the insulating capability of the phospholipid layer without significantly altering the bilayer structure. This model membrane will allow the assessment of the effect of lipid membrane perturbants on the insulating properties of natural lipid membranes.

W. Yap - One of the best experts on this subject based on the ideXlab platform.

  • supported phospholipid Alkanethiol biomimetic membranes insulating properties
    Biophysical Journal, 1994
    Co-Authors: Anne L. Plant, M. Gueguetchkeri, W. Yap
    Abstract:

    A novel model lipid bilayer membrane is prepared by the addition of phospholipid vesicles to Alkanethiol monolayers on gold. This supported hybrid bilayer membrane is rugged, easily and reproducibly prepared in the absence of organic solvent, and is stable for very long periods of time. We have characterized the insulating characteristics of this membrane by examining the rate of electron transfer and by impedance spectroscopy. Supported hybrid bilayers formed from phospholipids and Alkanethiols are pinhole-free and demonstrate measured values of conductivity and resistivity which are within an order of magnitude of that reported for black lipid membranes. Capacitance values suggest a dielectric constant of 2.7 for phospholipid membranes in the absence of organic solvent. The protein toxin, melittin, destroys the insulating capability of the phospholipid layer without significantly altering the bilayer structure. This model membrane will allow the assessment of the effect of lipid membrane perturbants on the insulating properties of natural lipid membranes.

  • Supported phospholipid/Alkanethiol biomimetic membranes: insulating properties
    Biophysical journal, 1994
    Co-Authors: Anne L. Plant, M. Gueguetchkeri, W. Yap
    Abstract:

    A novel model lipid bilayer membrane is prepared by the addition of phospholipid vesicles to Alkanethiol monolayers on gold. This supported hybrid bilayer membrane is rugged, easily and reproducibly prepared in the absence of organic solvent, and is stable for very long periods of time. We have characterized the insulating characteristics of this membrane by examining the rate of electron transfer and by impedance spectroscopy. Supported hybrid bilayers formed from phospholipids and Alkanethiols are pinhole-free and demonstrate measured values of conductivity and resistivity which are within an order of magnitude of that reported for black lipid membranes. Capacitance values suggest a dielectric constant of 2.7 for phospholipid membranes in the absence of organic solvent. The protein toxin, melittin, destroys the insulating capability of the phospholipid layer without significantly altering the bilayer structure. This model membrane will allow the assessment of the effect of lipid membrane perturbants on the insulating properties of natural lipid membranes.

Woong-ki Hong - One of the best experts on this subject based on the ideXlab platform.

  • Electrical and Optical Characterization of MoS2 with Sulfur Vacancy Passivation by Treatment with Alkanethiol Molecules
    AMER CHEMICAL SOC, 2018
    Co-Authors: Kyungjune Cho, Mi-sook Min, Tae-young Kim, Hyunhak Jeong, Jinsu Pak, Jae-keun Kim, Jingon Jang, Seok Joon Yun, Young Hee Lee, Woong-ki Hong
    Abstract:

    We investigated the physical properties of molybdenum disulfide (MoS2) atomic crystals with a sulfur vacancy passivation after treatment with Alkanethiol molecules including their electrical, Raman, and photoluminescence (PL) characteristics. MoS2, one of the transition metal dichalcogenide materials, is a promising two-dimensional semiconductor material with good physical properties. It is known that sulfur vacancies exist in MoS2, resulting in the n-type behavior of MoS2. The sulfur vacancies on the MoS2 surface tend to form covalent bonds with sulfur-containing groups. In this study, we deposited Alkanethiol molecules on MoS2 field effect transistors (FETs) and then characterized the electrical properties of the devices before and after the Alkanethiol treatment. We observed that the electrical characteristics of MoS2 FETs dramatically changed after the Alkanethiol treatment. We also observed that the Raman and PL spectra of MoS2 films changed after the Alkanethiol treatment. These effects are attributed to the thiol (-SH) end groups in Alkanethiols bonding at sulfur vacancy sites, thus altering the physical properties of the MoS2. This study will help us better understand the electrical and optical properties of MoS2 and suggest a way of tailoring the properties of MoS2 by passivating a sulfur vacancy with thiol molecules. (Figure Presented). © 2015 American Chemical Society575

  • Electrical and Optical Characterization of MoS2 with Sulfur Vacancy Passivation by Treatment with Alkanethiol Molecules.
    ACS nano, 2015
    Co-Authors: Kyungjune Cho, Mi-sook Min, Tae-young Kim, Hyunhak Jeong, Jinsu Pak, Jae-keun Kim, Jingon Jang, Seok Joon Yun, Young Hee Lee, Woong-ki Hong
    Abstract:

    We investigated the physical properties of molybdenum disulfide (MoS2) atomic crystals with a sulfur vacancy passivation after treatment with Alkanethiol molecules including their electrical, Raman, and photoluminescence (PL) characteristics. MoS2, one of the transition metal dichalcogenide materials, is a promising two-dimensional semiconductor material with good physical properties. It is known that sulfur vacancies exist in MoS2, resulting in the n-type behavior of MoS2. The sulfur vacancies on the MoS2 surface tend to form covalent bonds with sulfur-containing groups. In this study, we deposited Alkanethiol molecules on MoS2 field effect transistors (FETs) and then characterized the electrical properties of the devices before and after the Alkanethiol treatment. We observed that the electrical characteristics of MoS2 FETs dramatically changed after the Alkanethiol treatment. We also observed that the Raman and PL spectra of MoS2 films changed after the Alkanethiol treatment. These effects are attributed to the thiol (-SH) end groups in Alkanethiols bonding at sulfur vacancy sites, thus altering the physical properties of the MoS2. This study will help us better understand the electrical and optical properties of MoS2 and suggest a way of tailoring the properties of MoS2 by passivating a sulfur vacancy with thiol molecules.

Kyungjune Cho - One of the best experts on this subject based on the ideXlab platform.

  • Electrical and Optical Characterization of MoS2 with Sulfur Vacancy Passivation by Treatment with Alkanethiol Molecules
    AMER CHEMICAL SOC, 2018
    Co-Authors: Kyungjune Cho, Mi-sook Min, Tae-young Kim, Hyunhak Jeong, Jinsu Pak, Jae-keun Kim, Jingon Jang, Seok Joon Yun, Young Hee Lee, Woong-ki Hong
    Abstract:

    We investigated the physical properties of molybdenum disulfide (MoS2) atomic crystals with a sulfur vacancy passivation after treatment with Alkanethiol molecules including their electrical, Raman, and photoluminescence (PL) characteristics. MoS2, one of the transition metal dichalcogenide materials, is a promising two-dimensional semiconductor material with good physical properties. It is known that sulfur vacancies exist in MoS2, resulting in the n-type behavior of MoS2. The sulfur vacancies on the MoS2 surface tend to form covalent bonds with sulfur-containing groups. In this study, we deposited Alkanethiol molecules on MoS2 field effect transistors (FETs) and then characterized the electrical properties of the devices before and after the Alkanethiol treatment. We observed that the electrical characteristics of MoS2 FETs dramatically changed after the Alkanethiol treatment. We also observed that the Raman and PL spectra of MoS2 films changed after the Alkanethiol treatment. These effects are attributed to the thiol (-SH) end groups in Alkanethiols bonding at sulfur vacancy sites, thus altering the physical properties of the MoS2. This study will help us better understand the electrical and optical properties of MoS2 and suggest a way of tailoring the properties of MoS2 by passivating a sulfur vacancy with thiol molecules. (Figure Presented). © 2015 American Chemical Society575

  • Electrical and Optical Characterization of MoS2 with Sulfur Vacancy Passivation by Treatment with Alkanethiol Molecules.
    ACS nano, 2015
    Co-Authors: Kyungjune Cho, Mi-sook Min, Tae-young Kim, Hyunhak Jeong, Jinsu Pak, Jae-keun Kim, Jingon Jang, Seok Joon Yun, Young Hee Lee, Woong-ki Hong
    Abstract:

    We investigated the physical properties of molybdenum disulfide (MoS2) atomic crystals with a sulfur vacancy passivation after treatment with Alkanethiol molecules including their electrical, Raman, and photoluminescence (PL) characteristics. MoS2, one of the transition metal dichalcogenide materials, is a promising two-dimensional semiconductor material with good physical properties. It is known that sulfur vacancies exist in MoS2, resulting in the n-type behavior of MoS2. The sulfur vacancies on the MoS2 surface tend to form covalent bonds with sulfur-containing groups. In this study, we deposited Alkanethiol molecules on MoS2 field effect transistors (FETs) and then characterized the electrical properties of the devices before and after the Alkanethiol treatment. We observed that the electrical characteristics of MoS2 FETs dramatically changed after the Alkanethiol treatment. We also observed that the Raman and PL spectra of MoS2 films changed after the Alkanethiol treatment. These effects are attributed to the thiol (-SH) end groups in Alkanethiols bonding at sulfur vacancy sites, thus altering the physical properties of the MoS2. This study will help us better understand the electrical and optical properties of MoS2 and suggest a way of tailoring the properties of MoS2 by passivating a sulfur vacancy with thiol molecules.

P Bertrand - One of the best experts on this subject based on the ideXlab platform.

  • TOF-SIMS study of Alkanethiol adsorption and ordering on gold
    Applied Surface Science, 2001
    Co-Authors: L Houssiau, P Bertrand
    Abstract:

    A systematic study of Alkanethiol self-assembly on gold was undertaken with the time-of-flight-secondary ion mass spectrometry (TOF-SIMS) technique. Following adsorption, the TOF-SIMS spectra exhibit sulfur-containing peaks (specially AuxSx clusters) and a rise of all hydrocarbon peaks (CxHy). But the most specific peaks are those directly related to the adsorbed molecules (M) such as deprotonated monomers (M-H)(-), thiolate (MAu-). dimers (M2Au-), trimers (M3Au2-) and even tetramers (M4Au3-) By examining the ion yield of the most relevant fragments as a function of adsorption time, it is possible to follow the self-assembly kinetics for all the Alkanethiols chosen. The hydrocarbon and Au,S, peak intensities quickly rise and reach a saturation level after typically an adsorption period of a few minutes. However, the oligomer fragments exhibit a much slower rise and reach saturation only after a few hours. This observation corroborates the widely accepted theory of Alkanethiol adsorption on gold, starting with a fast adsorption of a disordered layer followed by a slower phase of monolayer self-assembly leading to a high packing of the alkane chains. The oligomer ions clearly reflect, to some extent, the degree of organization of the monolayer, whereas hydrocarbon and AuxSy, clusters just indicate the chemical changes at the surface. (C) 2001 Elsevier Science B.V. All rights reserved.

  • TOF–SIMS study of Alkanethiol adsorption and ordering on gold
    Applied Surface Science, 2001
    Co-Authors: L Houssiau, P Bertrand
    Abstract:

    A systematic study of Alkanethiol self-assembly on gold was undertaken with the time-of-flight-secondary ion mass spectrometry (TOF-SIMS) technique. Following adsorption, the TOF-SIMS spectra exhibit sulfur-containing peaks (specially AuxSx clusters) and a rise of all hydrocarbon peaks (CxHy). But the most specific peaks are those directly related to the adsorbed molecules (M) such as deprotonated monomers (M-H)(-), thiolate (MAu-). dimers (M2Au-), trimers (M3Au2-) and even tetramers (M4Au3-) By examining the ion yield of the most relevant fragments as a function of adsorption time, it is possible to follow the self-assembly kinetics for all the Alkanethiols chosen. The hydrocarbon and Au,S, peak intensities quickly rise and reach a saturation level after typically an adsorption period of a few minutes. However, the oligomer fragments exhibit a much slower rise and reach saturation only after a few hours. This observation corroborates the widely accepted theory of Alkanethiol adsorption on gold, starting with a fast adsorption of a disordered layer followed by a slower phase of monolayer self-assembly leading to a high packing of the alkane chains. The oligomer ions clearly reflect, to some extent, the degree of organization of the monolayer, whereas hydrocarbon and AuxSy, clusters just indicate the chemical changes at the surface. (C) 2001 Elsevier Science B.V. All rights reserved