Dispersion of Nanoparticles in Liquid Crystals by Sputtering and Its Effect on the Electrooptic Properties

  • YOSHIDA Hiroyuki
    Division of Electrical, Electronic and Information Engineering, Osaka Univ.
  • KAWAMOTO Kosuke
    Division of Electrical, Electronic and Information Engineering, Osaka Univ.
  • TANAKA Yuma
    Division of Electrical, Electronic and Information Engineering, Osaka Univ.
  • KUBO Hitoshi
    Division of Electrical, Electronic and Information Engineering, Osaka Univ.
  • FUJII Akihiko
    Division of Electrical, Electronic and Information Engineering, Osaka Univ.
  • OZAKI Masanori
    Division of Electrical, Electronic and Information Engineering, Osaka Univ.

Search this article

Abstract

The authors describe a method to produce gold nanoparticle-dispersed liquid crystals by means of sputtering, and discuss how the presence of gold nanoparticles affect the electro-optic response of the host liquid crystal. The method exploits the fact that liquid crystals possess low vapor pressures which allow them to undergo the sputtering process, and the target material is sputtered directly on the liquid crystal in a reduced air pressure environment. The sample attained a red-brownish color after sputtering, but no aggregations were observed in the samples kept in the liquid crystal phase. Polarization optical microscopy of the sample placed in a conventional sandwich cell revealed that the phase transition behaviour is affected by the presence of the nanoparticles and that the onset of the nematic phase is observed in the form of bubble-like domains whereas in the pure sample the nematic phase appears after the passing of a phase transition front. Transmission electron microscopy confirmed the presence of single nano-sized particles that were dispersed without forming aggregates in the material. The electro-optic properties of the nanoparticle-dispersed liquid crystal was investigated by measuring the threshold voltage for a twisted-nematic cell. The threshold voltage was found to depend on the frequency of the applied rectangular voltage, and at frequencies higher than 200Hz, the threshold became lower than the pure samples.

Journal

  • IEICE Transactions on Electronics

    IEICE Transactions on Electronics E93-C (11), 1595-1601, 2010

    The Institute of Electronics, Information and Communication Engineers

References(29)*help

See more

Related Projects

See more

Details 詳細情報について

Report a problem

Back to top