Extraordinary properties of nematic phases of bent-core liquid crystals

A. Jákli, M. Chambers, J. Harden, M. Madhabi, R. Teeling, J. Kim, Q. Li, G. G. Nair, N. Éber, K. Fodor-Csorba, J. T. Gleeson, S. Sprunt

Research output: Chapter in Book/Report/Conference proceedingConference contribution

12 Citations (Scopus)

Abstract

We briefly review systematic and comprehensive studies on several chlorine-substituted bent-core liquid crystal materials in their nematic phases. The results, in comparison to rod-shaped molecules, are both extraordinary and technologically significant. Specifically: a) Electrohydrodynamic instabilities provide unique patterns including well defined, periodic stripes and optically isotropic structures. b) Rheological measurements using different probe techniques (dynamic light scattering, pulsed magnetic field, electrorotation) reveal that the ratio of the flow and rotational viscosities are over two orders of magnitudes larger in bentcore than in calamitic materials which proves that the molecule shape and not its size is responsible for this behaviour. c) Giant flexoelectric response, as measured by dynamic light scattering and by directly probing the induced current when the material is subject to oscillatory bend deformation, turns out to be more than three orders of magnitude larger than in calamities and 50 times larger than molecular shape considerations alone would predict. The magnitude of this effect renders these materials as promising candidates for efficient conversion between mechanical and electrical energy. d) The converse of this effect when the bent-core material sandwiched between plastic substrates 4 times thicker than the liquid crystal material provided displacements in the range of 100nm that is sensitive to the polarity of the applied field thus suggesting applications as beam steering and precision motion controls.

Original languageEnglish
Title of host publicationEmerging Liquid Crystal Technologies III
DOIs
Publication statusPublished - May 15 2008
EventEmerging Liquid Crystal Technologies III - San Jose, CA, United States
Duration: Jan 20 2008Jan 22 2008

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume6911
ISSN (Print)0277-786X

Other

OtherEmerging Liquid Crystal Technologies III
CountryUnited States
CitySan Jose, CA
Period1/20/081/22/08

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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  • Cite this

    Jákli, A., Chambers, M., Harden, J., Madhabi, M., Teeling, R., Kim, J., Li, Q., Nair, G. G., Éber, N., Fodor-Csorba, K., Gleeson, J. T., & Sprunt, S. (2008). Extraordinary properties of nematic phases of bent-core liquid crystals. In Emerging Liquid Crystal Technologies III [691105] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 6911). https://doi.org/10.1117/12.768866