Molecular or Nanoscale Structures? The Deciding Factor of Surface Properties on Functionalized Poly(3,4-ethylenedioxythiophene) Nanorod Arrays

Authors

  • Hsing-An Lin,

    1. Yu Initiative Research Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
    2. Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8502, Japan
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  • Shyh-Chyang Luo,

    Corresponding author
    1. Yu Initiative Research Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
    • Yu Initiative Research Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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  • Bo Zhu,

    Corresponding author
    1. Yu Initiative Research Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
    • Yu Initiative Research Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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  • Chi Chen,

    1. Nanophotonics Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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  • Yoshiro Yamashita,

    Corresponding author
    1. Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8502, Japan
    • Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8502, Japan.
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  • Hsiao-hua Yu

    Corresponding author
    1. Yu Initiative Research Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
    • Yu Initiative Research Unit, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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Abstract

Nanostructures of poly(3,4-ethylenedioxythiophene) (PEDOT) are assembled by using an anodic aluminum oxide template directly fabricated on gold-coated silicon wafers. Inside these templates, PEDOT and hydroxy functionalized PEDOT form tubes. On the other hand, alkyl- and perfluoro-functionalized PEDOTs assembled as nanorods. This approach allows a platform to understand the molecular and nanostructural effect on the surface wettability of these materials. In the water/air interface, the contact angle of water droplet (CAwater) for the smooth alkyl-functionalized PEDOT films increases when alkyl chain gets longer. In contrast, the contact angle reachs saturation at 130° with alkyl chain longer than ethyl in assembled nanorod arrays. It remains the same even in the case of perfluoro-functionalized PEDOT. Moreover, ethyl-functionalized PEDOT (PEDOT-C2) nanorods displays superoleophilicity and the oil deoplet cannot stay on the film in water. Based on the wettability studies, it is concluded that the nanostructures contribute predominantly for the surface wettability of these nanomaterials when the length of alkyl chain crosses certain threshold.

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