• Title/Summary/Keyword: noncovalent functionalization

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Noncovalent Modification of Carbon Nanofibers Using 2-Naphthalenethiol for Catalyst Supports in PEM Fuel Cells

  • Oh, Hyung-Suk;Kim, Han-Sung
    • Journal of Electrochemical Science and Technology
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    • v.1 no.2
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    • pp.92-96
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    • 2010
  • A new synthesis method for the preparation of Pt electrocatalysts on carbon nanofibers (CNFs) is reported. In this method, Pt electrocatalysts are loaded onto 2-naphthalenethiol (NT) functionalized CNFs. The noncovalent functionalization of CNFs by NT is the effective way for better distribution of Pt particles and higher electrocatalytic activity in polymer electrolyte membrane fuel cells. It was found that the presence of NT acts as a poison to catalysts. Therefore, it is necessary to remove NT through the heat treatment at $400^{\circ}C$.

Fabrication of top gate Graphene Transistor with Atomic Layer Deposited $Al_2O_3$

  • Kalode, Pranav;Seong, Myeong-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.212-212
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    • 2013
  • We fabricate and characterize top gate Graphene transistor using aluminum oxide as a gate insulator by atomic layer deposition (ALD). It is found that due to absence of functional group and dangling bonds, ALD of metal oxide is difficult on Graphene. Here we used 4-mercaptopheneol as a functionalization layer on Graphene to facilitate uniform oxide coverage. Contact angle measurement and Atomic force microscopy were used to confirm uniform oxide coverage on Graphene. Raman spectroscopy revealed that functionalization with 4-mercaptopheneol does not induce any defect peak on Graphene. Our device shows mobility values of 4,000 $cm^2/Vs$ at room temperature which also suggest top gate stack does not significantly increase scattering. The noncovalent functionalization method is non-destructive and can be used to grow ultra-thin dielectric for future Graphene applications.

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Dispersion Behavior of Graphene with Different Solvents and Surfactants (용매와 분산제의 종류에 따른 그래핀의 분산 거동)

  • Perumal, Suguna;Lee, Hyang Moo;Cheong, In Woo
    • Journal of Adhesion and Interface
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    • v.20 no.2
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    • pp.53-60
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    • 2019
  • Stable graphene dispersions in various organic solvents and in water were achieved via noncovalent functionalization of graphene surfaces using different types of commercially available surfactants. Stable dispersions were obtained in short time sonication, 3 h. In NMP, graphene with Tween and Span series, and with Pluronic surfactants showed stable dispersions. In ethanol, nitrogen based surfactants showed stable dispersions. In water and dichloromethane partially stable graphene dispersions were obtained using poly(4-vinyl pyridine) and sodium dodecyl sulfonate surfactants. Large scale productions of stable dispersions were successful using poly(4-vinyl pyridine), poly(vinyl pyrrolidone), and poly(2-(dimethylamino)ethyl methacrylate). Thus, this work will serve as a library to select the surfactants for different solvent systems.