title: Discontinuous anchoring transition and photothermal switching in composites of liquid crystals and conducting polymer nanofibers.
abstract: We prepared nanocomposites of a nematic liquid crystal and nanofibers of a conducting polymer (polyaniline). All the nanocomposites exhibit a discontinuous surface anchoring transition from planar to homeotropic in the nematic phase on a perfluoropolymer coated surface with a thermal hysteresis (≈ 5.3 °C). We observe a relatively large bistable conductivity and demonstrate a light driven switching of conductivity and dielectric constant in dye doped nanocomposites in the thermal hysteresis (bistable) region. The experimental results have been explained based on the reorientation of the nanofibers driven by the anchoring transition of the nematic liquid crystal. We show a significant enhancement of the bistable temperature range (≈ 13 °C) by an appropriate choice of compound in the binary system.
authors.affiliation: School of Physics, University of Hyderabad, Hyderabad 500046, India.
authors.forename: M V
authors.initials: MV
authors.lastname: Rasna
authors.affiliation: School of Physics, University of Hyderabad, Hyderabad 500046, India.
authors.forename: K P
authors.initials: KP
authors.lastname: Zuhail
authors.affiliation: School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046, India.
authors.forename: R
authors.initials: R
authors.lastname: Manda
authors.affiliation: School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046, India.
authors.forename: P
authors.initials: P
authors.lastname: Paik
authors.affiliation: Darmstadt University of Technology, Eduard Zintl Institute for Inorganic and Physical Chemistry, Petersenstrasse 20, Darmstadt 64287, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Haase
authors.affiliation: School of Physics, University of Hyderabad, Hyderabad 500046, India.
authors.forename: Surajit
authors.initials: S
authors.lastname: Dhara
mesh_terms: D003198:Computer Simulation; D004553:Electric Conductivity; D004574:Electromagnetic Fields; D005466:Fluorocarbons / Q000737:chemistry* / Q000528:radiation effects; D006358:Hot Temperature; D008027:Light; D050866:Liquid Crystals / Q000737:chemistry* / Q000528:radiation effects; D008956:Models, Chemical; D008968:Molecular Conformation / Q000528:radiation effects; D057139:Nanofibers / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure*; D044367:Phase Transition
chemical_list: D005466:Fluorocarbons