Dynamics of Rotational Motion in Liquid Crystalline Systems

  • W. Stille
  • G. R. Strobl


Liquid crystals combine the anisotropic optical properties, as they are typical for birefringent crystals, with the viscous behaviour of liquids [1, 2]. Application of these materials is based on this specific pattern of properties. Well known, and of great technological importance is the use of nematic liquid crystals in modern displays. Here electrical fields are applied to induce local changes in the orientation of the optic axis. Switching times should be as short as possible and usually are in the order of 10–100 ms. The decisive parameter is the rotational viscosity γ, which describes the ratio between the torque acting on the director (i.e. the optic axis) and its angular velocity. For displays low values of γl are desirable. In a different range of applications nematogenic materials are used to prepare optical components with specific permanent birefringence profiles. Principally this can be achieved by setting up in the nematic phase a specific director field and then fixing it by a quench into the glassy state. This procedure is now gaining special importance in attempts to produce components with nonlinear optical properties. Liquid crystalline polymers, composed of mesogenic groups which are laterally attached to a flexible backbone chain, constitute a class of materials which is convenient for this purpose [3, 4]. These “LC-side group polymers” usually show a glass transition at temperatures above room temperature, so that optical structures prepared in the nematic phase can be fixed by a quenching and then remain stable at ambient temperature.


Rotational Motion Nematic Liquid Crystal Nematic Phase Rotational Diffusion Liquid Crystalline Polymer 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    De Gennes PG (1974) The physics of liquid crystals. Clarendon, OxfordGoogle Scholar
  2. 2.
    Vertogen G, de Jeu WH (1988) Thermotropic liquid crystals, fundamentals. Springer, Berlin Heidelberg New YorkGoogle Scholar
  3. 3.
    Finkelmann H, Ringsdorf H, Wendorff H (1978) Makromol Chem 179:273Google Scholar
  4. 4.
    Donald AM, Windle AH (1992) Liquid crystalline polymers. Cambridge University Press, CambridgeGoogle Scholar
  5. 5.
    Doi M, Edwards SF (1986) The theory of polymer dynamics. Clarendon, OxfordGoogle Scholar
  6. 6.
    Marrucci G (1982) Mol Cryst Liq Cryst 72:153CrossRefGoogle Scholar
  7. 7.
    Tseber AO (1978) Magn Gidrod 3:3Google Scholar
  8. 8.
    McArdle CB (1989) Side chain liquid crystal polymers. Blackie, LondonGoogle Scholar
  9. 9.
    Finkelmann H (1991) In: Ciferri A (ed) Liquid crystallinity in polymers: principles and fundamental properties, VCH Publishers, Weinheim, p 315Google Scholar
  10. 10.
    Brochard F (1979) J Polym Sci Polym Phys Ed 17:1367CrossRefGoogle Scholar
  11. 11.
    Kirste R, Ohm H (1985) Makromol Chem, Rapid Commun. 6:179CrossRefGoogle Scholar
  12. 12.
    Hardouin F, Leroux N, Mery S, Noirez L (1992) J Phys II France 2:271CrossRefGoogle Scholar
  13. 13.
    Mattoussi H, Ober R, Veyssie M, Finkelmann H (1986) Europhys Lett 2:233CrossRefGoogle Scholar
  14. 14.
    Martin AJ, Meier G, Saupe A (1971) Symp Faraday Soc 5:119CrossRefGoogle Scholar
  15. 15.
    Seiberle H, Stille W, Strobl G (1990) Macromolecules 23:2008CrossRefGoogle Scholar
  16. 16.
    Götz S, Stille W, Strobl G (1993) Macromolecules 26:1520CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1994

Authors and Affiliations

  • W. Stille
  • G. R. Strobl

There are no affiliations available

Personalised recommendations