Cover Picture: UV-Light-Induced Swelling and Visible-Light-Induced Shrinking of a TiO2-Containing Redox Gel (Adv. Mater. 9/2007)

Authors

  • T. Tatsuma,

    1. Institute of Industrial Science, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8505 (Japan)
    2. PRESTO, Japan Science and Technology Agency, Honcho, Kawaguchi-shi, Saitama 332-0012 (Japan)
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  • K. Takada,

    1. Institute of Industrial Science, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8505 (Japan)
    2. Present address: Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555, Japan
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  • T. Miyazaki

    1. Institute of Industrial Science, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8505 (Japan)
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Abstract

Polyacrylate gels containing Ag+ and TiO2 nanoparticles are shown to swell under UV light and shrink under visible light in water. In work reported by Tetsu Tatsuma and co-workers on p. 1249, the TiO2 absorbs UV light and reduces the Ag+, whereas the deposited Ag absorbs visible light and dissolves itself. These redox reactions change the interactions between the polymer chains and eventually the volume of the gel, as shown on the cover.

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