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Combined electric and photocontrol of selective light reflection by oblique helicoidal cholesteric doped with azobenzene derivative

ORAL

Abstract

A cholesteric liquid crystal (ChLC) composed of flexible dimeric molecules shows an oblique helicoidal state (ChOH) in the presence of an electric field. By controlling the ChOH pitch P by the electric field, one can shift the wavelength of the selective reflection (transmission) of light in a broad spectral range, from UV to IR. In this work, we demonstrate that a combined action of the electric field and UV irradiation could continuously tune the pitch of a ChOH material doped with photosensitive azobenzene molecules capable of trans-cis isomerization. At a fixed voltage, UV irradiation causes a gradual redshift of the reflection wavelength by about 100 nm for the explored composition. The dynamic scenarios of the radiation-induced changes are described by kinetic equations. The phenomenon can find applications such as smart windows, lasers, optical filters, and sensors of UV intensities/doses.

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Presenters

  • Kamal Thapa

    Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA

Authors

  • Kamal Thapa

    Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA

  • Olena Iadlovska

    Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA, Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA

  • Hari Krishna Bisoyi

    Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA

  • Daniel Paterson

    Department of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, AB24 3UE Scotland, United Kingdom

  • John Storey

    Department of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, AB24 3UE Scotland, United Kingdom

  • Corrie T. Imrie

    Department of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, AB24 3UE Scotland, United Kingdom

  • Quan Li

    Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA

  • Sergij V Shiyanovskii

    Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA, Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA

  • O Lavrentovich

    Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA, Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA, Department of Physics, Kent State University, Advanced Materials and Liquid Crystal Institute, Department of Physics, Materials Science Graduate Program, Kent State University, Department of Physics and Advanced Materials and Liquid Crystal Institute, Kent State University, Advanced Materials and Liquid Crystal Institute, Kent State University