https://doi.org/10.1140/epje/i2010-10586-2
Regular Article
Morphology of open films of discotic hexagonal columnar liquid crystals as probed by grazing incidence X-ray diffraction
1
Centre de Recherche Paul-Pascal, Université de Bordeaux, 115 Avenue Schweitzer, 33600, Pessac, France
2
Insitut des Nanosciences de Paris, Universités Paris 6 et 7, 140 Rue de Lourmel, 75015, Paris, France
3
Université Paris 5 René Descartes, 45 rue des Saints Pères, 75231, Paris Cedex 06, France
* e-mail: grelet@crpp-bordeaux.cnrs.fr
Received:
12
January
2010
Revised:
24
February
2010
Accepted:
3
March
2010
Published online:
10
April
2010
The structure and the orientation of thermotropic hexagonal columnar liquid crystals are studied by grazing incidence X-ray diffraction (GIXD) for different discotic compounds in the geometry of open supported thin films. Whatever the film deposition mode (either spin-coating or vacuum evaporation) and the film thickness, a degenerate planar alignment with the liquid crystalline columns parallel to the substrate is found. However, if a specific thermal process is applied to the liquid crystal film, homeotropic anchoring (columns normal to the interface) can be stabilized in a metastable state.
© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg, 2010
