Azimuthal and polar anchoring energies of aligning layers structured by nonlinear laser lithography


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Pavlov I. , Candemir O., Rybak A., Dobrovolskiy A., Kadan V., Blonskiy I., ...More

Liquid Crystals, vol.48, no.1, pp.131-149, 2021 (Journal Indexed in SCI Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 48 Issue: 1
  • Publication Date: 2021
  • Doi Number: 10.1080/02678292.2020.1766589
  • Title of Journal : Liquid Crystals
  • Page Numbers: pp.131-149
  • Keywords: Aligning layers, azimuthal anchoring energy, polar anchoring energy, nematic liquid crystals, contact angle, Creagh-Kmetz's rule, nano-structured titanium layers, nonlinear laser lithography, NEMATIC LIQUID-CRYSTAL, ALIGNMENT, SURFACE, PLANAR, DEPENDENCE, STRENGTH, EXPOSURE, ANGLE

Abstract

© 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group.In spite of the fact that there are different techniques in the creation of the high-quality liquid crystals (LCs) alignment by means of various surfaces, the azimuthal and polar anchoring energies as well as the pre-tilt angle are important parameters to all of them. Here, the modified by a certain manner aligning layers, previously formed by nonlinear laser lithography (NLL), having high-quality nano-periodic grooves on Ti surfaces, recently proposed for LC alignment was studied. The change of the scanning speed of NLL in the process of nano-structured Ti surfaces and their further modification by means of ITO-coating, and deposition of polyimide film has enabled different aligning layers, whose main characteristics, namely azimuthal and polar anchoring energies, were measured. For the modified aligning layers, the dependencies of the twist and pre-tilt angles for LC cells filled by nematic E7 (Δε > 0) and MLC-6609 (Δε < 0) were obtained. Also, the contact angle for droplets of isotropic liquid (glycerol), and nematic LCs was measured for the various values of the scanning speed during the laser processing.