Structural Transformations in Lyotropic Liquid Crystals

  • J. Charvolin
Part of the Ettore Majorana International Science Series book series (EMISS, volume 41)


The broad lines of the polymorphism of assemblies of amphiphilic molecules in presence of water are now well drawn. They can be found in basic review articles about phase diagrams[1,2] and structures[3,4]. These presentations are limited to descriptions of phase diagrams and structures; they do not consider the processes by which one structure transforms into another when the thermodynamical parameters of the phase diagram, water content and temperature, vary. In order to approach this problem we shall first analyze the structures described in the above classical works in purely geometrical terms. We shall consider them as organizations of space in two media, aqueous and paraffinic, of various connectivities. This will lead us to distinguish two classes of structural transformations: one corresponding to transformations without change of connectivity in the two media; the other corresponding to transformations with changes of connectivity. In the first case there is only growth, deformation and ordering of aggregates of amphiphilic molecules, without topological change. Thermodynamical models of aggregation and ordering, inspired from those developed for micellar aggregation and ordering of molecular crystals and thermotropic liquid crystals can give account, and in a few examples predict, some aspects of the phase transformations. In the second case the appearance of new connections between the aggregates when the transformation takes place changes the topology of the system. Such changes cannot be predicted by the above models and require specific treatments. This imposed the search for a more general frame within which the essential features of these models might be used. We shall propose a geometrical approach which consists in looking at the various structures as solutions to “frustrations” in the bilayers of the lamellar phases. Finally, we shall describe a few recent experimental studies which lead to the revision of some aspects of the classical descriptions, in agreement with the above proposition.


Phase Diagram Liquid Crystal Lamellar Phase Amphiphilic Molecule Lyotropic Liquid Crystal 
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.
    P. Ekwall, Composition, properties and structures of liquid crystalline phases in systems of amphiphilic compounds, in “Advances in Liquid Crystals”, vol. 1, G. H. Brown ed., Academic Press, New York (1978).Google Scholar
  2. 2.
    A. Skoulios, Amphiphiles: organisation et diagrammes de phases, Ann. Phys. 3, 421 (1978).Google Scholar
  3. 3.
    V. Luzzati, X-ray diffraction studies of lipid-water systems, in “Biological Membranes”, vol. 1, D. Chapman ed., Academic Press, New-York (1967).Google Scholar
  4. 4.
    J. Charvolin and Y. Hendrikx, Lyotropic nematic phases of amphiphilic compounds, in “Liquid Crystals of One and Two Dimensional Order”, W. Helfrich and G. Heppke ed., Springer-Verlag, Berlin (1980).Google Scholar
  5. 5.
    Y. Hendrikx and J. Charvolin, Structural relations between lyotropic phases in the vicinity of the nematic phases, J. Physique, 42, 1427 (1981).CrossRefGoogle Scholar
  6. 6.
    L. J. Yu and A. Saupe, Observation of a biaxial nematic phase, Phys. Rev. Lett. 45, 1000 (1980).ADSCrossRefGoogle Scholar
  7. 7.
    W. M. Gelbard, A. Ben Shaul, W. E. McMullen and A. Masters, Micellar growth due to interaggregate interaction, J. Phys. Chem. 88, 861 (1984).CrossRefGoogle Scholar
  8. W. E. McMullen, A. Ben Shaul and W. M. Gelbart, Rod/disk coexistence in dilute soap solutions, J. Coll. Interface Sci. 98, 523 (1984).Google Scholar
  9. W. M. Gelbart, W. E. McMullen, A. Masters and A. Ben Shaul, Partitioning of cosurfactants in mixed micelles: size enhancement and nematic stability, Langmuir, 1, 101 (1985).CrossRefGoogle Scholar
  10. W. M. Gelbart, W. E. McMullen and A. Ben Shaul, Nematic stability and the alignment induced growth of anisotropic micelles, J. Physique, 46, 1137 (1985).CrossRefGoogle Scholar
  11. 8.
    W. M. Gelbart, A. Ben Shaul, A. Masters and W. E. McMullen, Effects of interaggregate forces on micellar size, in “Physics of Amphiphiles: Micelles, Vesicles and Micro-emulsion”, V. Degiogio and M. Corti ed., North-Holland, Amsterdam (1984).Google Scholar
  12. 9.
    J. Charvolin, From micelles to liquid crystals, Mol. Cryst. Liq. Cryst. 113, 1 (1984).CrossRefGoogle Scholar
  13. 10.
    Y. Hendrikx, J. Charvolin and M. Rawiso, Segregation of two amphiphilic molecules within non-spherical micelles, J. Coll. Interface Sci. 100, 597 (1984).CrossRefGoogle Scholar
  14. 11.
    S. Alpérine, “Etudes structurales de transformations de phase dans des cristaux liquides lyotropes.” Thèse de doctorat de troisième cycle, Orsay (1985).Google Scholar
  15. S. Alpérine, Y. Hendrikx and J. Charvolin, in preparation.Google Scholar
  16. 12.
    S. Alpérine, Y. Hendrikx and J. Charvolin, Internal structure of aggregates of two amphiphilic molecules in a lyotropic liquid crystal, J. Physique Lett. 46, L-27 (1985).Google Scholar
  17. 13.
    J. Charvolin, Crystals of interfaces: the cubic phases of amphiphile/ water systems, J. Physique, 46, C3–173 (1985).MathSciNetGoogle Scholar
  18. 14.
    J. F. Sadoc and J. Charvolin, Frustrations in bilayers, J. Physique, 47, 683 (1986). J. Charvolin and J.F. Sadoc, Bicontinuous cubic phases, J. Physique 48, 1559 (1987).Google Scholar
  19. 15.
    M. C. Holmes and J. Charvolin, Smectic-Nematic Transition in a lyotropic liquid crystal, J. Phys. Chem. 88, 810 (1984).CrossRefGoogle Scholar
  20. 16.
    P. Kékicheff, B. Cabane and M. Rawiso, Structural defects of a lamellar lyotropic mesophase, J. Physique Lett. 45, L813 (1984).CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1989

Authors and Affiliations

  • J. Charvolin
    • 1
  1. 1.Laboratoire de Physique des SolidesUniversité Paris-SudOrsayFrance

Personalised recommendations