Uniaxial and biaxial liquid crystal phases in colloidal dispersions of board-like particles
Dispersions of board-like goethite (α-FeOOH) particles with short-range repulsive interaction form a versatile colloidal model system, showing a nematic, smectic A and columnar phase. In high magnetic fields a biaxial nematic phase is induced with the shortest dimension of the particles aligned alon...
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Published in | Liquid crystals Vol. 37; no. 6-7; pp. 641 - 651 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Abingdon
Taylor & Francis
01.06.2010
Taylor & Francis Ltd |
Subjects | |
Online Access | Get full text |
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Summary: | Dispersions of board-like goethite (α-FeOOH) particles with short-range repulsive interaction form a versatile colloidal model system, showing a nematic, smectic A and columnar phase. In high magnetic fields a biaxial nematic phase is induced with the shortest dimension of the particles aligned along the field. Moreover, if particles have a shape almost exactly in between rod-like and plate-like they can spontaneously, without external magnetic field, form biaxial nematic and biaxial smectic A phases, which is in accordance with theoretical predictions. The macroscopic domains were oriented by a magnetic field and their structure was revealed by small-angle X-ray scattering. Our results suggest that biaxial phases can be readily obtained by a proper choice of the particle shape. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0267-8292 1366-5855 |
DOI: | 10.1080/02678291003798164 |