, Volume 35, Issue 9–12, pp 539–542 | Cite as

Determination of molecular diffusion coefficients in liquid crystal 4,4′-bis(heptyloxy)azoxybenzene by gas chromatography

  • I. Medina


The molecular diffusion coefficients of xylene isomers have been determined at different temperatures in the three phases (smectic, nematic and isotropic) of 4,4′-bis(heptyloxy)azoxybenzene (BHOAB) by gas chromatography. The results obtained are discussed in terms of molar volume, polarity and length-to-breadth ratio of several isomers. The activation energy of diffusion processes of solutes in the three phases of the liquid crystal has been calculated.

Key Words

Gas chromatography Liquid crystals Diffusion coefficients Xylenes 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    H. Kelker, Ber. Bunsenges. Phys. Chem.67, 698 (1963).Google Scholar
  2. [2]
    Z. Witkiewicz, J. Chromatogr.208, 311 (1982).CrossRefGoogle Scholar
  3. [3]
    J. Coca, I. Medina, S. Langer, Chromatographia25, 825 (1988).CrossRefGoogle Scholar
  4. [4]
    E. Grushka, J. F. Solsky, Anal. Chem.45, 1836 (1973).CrossRefGoogle Scholar
  5. [5]
    E. Grushka, J. F. Solsky, J. Chromatogr.112, 145 (1975).CrossRefGoogle Scholar
  6. [6]
    I. Medina, accepted for publication in Liquid Crystals.Google Scholar
  7. [7]
    J. C. Giddings, S. L. Seager, J. Chem. Phys.35, 2242 (1961).CrossRefGoogle Scholar
  8. [8]
    J. F. Bocquet, C. Pommier, J. Chromatogr.205, 239 (1981).CrossRefGoogle Scholar
  9. [9]
    W. Marciniak, Z. Witkiewicz, J. Chromatogr.207, 333 (1981).CrossRefGoogle Scholar
  10. [10]
    R. C. Reid, J. M. Prausnitz, T. K. Sherwood, “The Properties of Gases and Liquids”, McGraw-Hill, New York (1977).Google Scholar
  11. [11]
    A. Radecki, H. Lamparczyk, R. Kaliszan, Chromatographia12, 595 (1979).Google Scholar
  12. [13]
    R. C. Weast, “Handbook of Chemistry and Physics”, Chemical Rubber Co., Cleveland (1983).Google Scholar

Copyright information

© Friedr. Vieweg & Sohn Verlagsgesellschaft mbH 1993

Authors and Affiliations

  • I. Medina
    • 1
  1. 1.Department of Chemical EngineeringUniversity of OviedoOviedoSpain

Personalised recommendations