Experimental Results and Problems Concerning “Blue Phases”

  • H. Stegemeyer
  • K. Bergmann
Part of the Springer Series in Chemical Physics book series (CHEMICAL, volume 11)

Abstract

Most of the cholesteric mesophases formed by esters of cholesterol exhibit selective reflection of circularly polarized light in the u. v. region at temperatures close below the clearing point /1/. The well known reflection colours in the visible either occur near phase transitions to the smectic phase or in so-called compensated mixtures /1/. However, cooling down cholesteric esters only a few tenths of a Kelvin below the clearing point bright colours appear (mostly blue colours) which disappear on further cooling /2/. As early as in 1906 Lehmann /3/ noted that these colours belong to an optically isotropic modification. In his opinion this modification represents a stable phase distinct from that of the ordinary cholesteric one.

Keywords

Cholesterol Crystallization Enthalpy Calorimetry Turbidity 

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References

  1. 1.
    H. Stegemeyer: VDI-Berichte 198, 29 (1973)Google Scholar
  2. 2.
    G.W. Gray, P.A. Winsor: Liquid Crystals and Plastic Crystals, Vol. 1, p. 12 (Ellis Horwood Ltd., Chichester 1974)Google Scholar
  3. 3.
    O. Lehmann: Z. Phys. Chem. 56, 750 (1906)Google Scholar
  4. 4.
    G.W. Gray: J. Chem. Soc. 1955, 3733Google Scholar
  5. 5.
    D. Armitage, F.P. Price: J. Phys. (Paris) Colloq. C 1, 36, C 1–133 (1975)Google Scholar
  6. 6.
    E.M. Barrall, R.S. Porter, J. F. Johnson: Mol Cryst. 3, 103 (1967)CrossRefGoogle Scholar
  7. 7.
    H. Arnold, P. Roediger: Z. Phys. Chem. 239, 283 (1968)Google Scholar
  8. 8.
    D. Armitage, F.P. Price: J. Appl. Phys. 47, 2735 (1976)ADSCrossRefGoogle Scholar
  9. 9.
    A. Saupe: Mol. Cryst. Liq. Cryst. 7, 59 (1969)CrossRefGoogle Scholar
  10. 10.
    G. Pelzl, H. Sackmann: Z. Phys. Chem. 254, 354 (1973)Google Scholar
  11. 11.
    D. Demus, H.G. Hahn, F. Kuschel: Mol. Cryst. Liq. Cryst. 44, 61 (1978)Google Scholar
  12. 12.
    K. Bergmann, H. Stegemeyer: Ber. Bunsenges. Phys. Chem. 82, 1309 (1978)Google Scholar
  13. 13.
    M.F. Vuks: Opt. Spectrosc. 20, 361 (1966)ADSGoogle Scholar
  14. 14.
    K. Bergmann, H. Stegemeyer: Z. Naturf. 34a, 251 (1979)ADSGoogle Scholar
  15. 15.
    K. Bergmann: Thesis, Paderborn 1980Google Scholar
  16. 16.
    K. Bergmann, P. Pollmann, G. Scherer, H. Stegemeyer: Z. Naturf. 34a, 253 (1979)ADSGoogle Scholar
  17. 17.
    K. Bergmann, H. Stegemeyer; Z. Naturf. 34a, 1031 (1979)ADSGoogle Scholar
  18. 18.
    S. Meiboom, M. Sammon: to be publishedGoogle Scholar
  19. 19.
    T.K. Brog, P.J. Collings: to be publishedGoogle Scholar
  20. 20.
    H. de Vries: Acta Crystallogr. 4, 219 (1951)CrossRefGoogle Scholar
  21. 21.
    J.L. Fergason: Mol. Cryst. 1, 293 (1966)CrossRefGoogle Scholar
  22. 22.
    L.S. Goldberg, J.M. Schnur: Radio Electron. Eng. 39, 279 (1970)CrossRefGoogle Scholar
  23. 23.
    P. Pollmann, G. Scherer: High Temp. High Pressure, 12, 103 (1980)Google Scholar
  24. 23a.
    G. Scherer: Thesis, Paderborn 1979Google Scholar
  25. 24.
    D. Coates, G.W. Gray: Phys. Letters 45 A, 115 (1973)Google Scholar
  26. 25.
    D. Demus, L. Richter: Texture of Liquid Crystals, p. 60 (Verlag Chemie Weinheim, New York 1978)Google Scholar
  27. 25a.
    D. Demus, L. Richter: Texture of Liquid Crystals, p. 184 (Verlag Chemie Weinheim, New York 1978)Google Scholar
  28. 26.
    I.G. Chistiakov, L.A. Gusakova: Kristallogr. 14, 153 (1969)Google Scholar
  29. 27.
    D. Coates, G.W. Gray: Phys. Letters 51 A, 335 (1975)ADSGoogle Scholar
  30. 28.
    H. Finkelmann, H. Stegemeyer: Ber. Bunsenges. Phys. Chem. 82, 1302 (1978)Google Scholar
  31. 29.
    G.W. Gray, P.A. Winsor: Liquid Crystals and Plastic Crystals, Vol. 1 (Ellis Horwood Ltd., Chichester 1974) Ref. 2, p. 16Google Scholar
  32. 30.
    W. Kuczynski, K. Bergmann, H. Stegemeyer: Mol Cryst. Liq. Cryst. Letters, in pressGoogle Scholar
  33. 31.
    H. Schroder: in The Molecular Properties of Liquid Crystals, Report of the Nato-Conference, Cambridge 1977 (G.R. Luckhurst, G.W. Gray ed., Academic Press, New York, in press)Google Scholar
  34. 32.
    S.A. Brazovskii, S.G. Dmitriev: Sov. Phys. JETP 42, 497 (1976)ADSGoogle Scholar
  35. 33.
    H. Schröder: to be published; these proceedings, p. 201Google Scholar
  36. 34.
    R.M. Hornreich, S. Shtrikman: J. Phys. (Paris), to be publishedGoogle Scholar
  37. 35.
    P.P. Crooker: private communicationGoogle Scholar
  38. 36.
    W. Kuczynski, H. Stegemeyer: Naturwiss., in pressGoogle Scholar
  39. 37.
    F. Reinitzer: Monatsh. Chem. 9, 421 (1888)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1980

Authors and Affiliations

  • H. Stegemeyer
    • 1
  • K. Bergmann
    • 1
  1. 1.Department of Physical ChemistryUniversity of PaderbornPaderbornFederal Republic of Germany

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