Tetravalent colloids by nematic wettingM. Huber1, 2 and H. Stark1
1 Universität Konstanz, Fachbereich Physik, D-78457 Konstanz, Germany
2 Department of Physics and Astronomy, University of British Columbia 6224 Agricultural Road, Vancouver, B.C. V6T1Z1, Canada
received 23 July 2004; accepted in final form 2 November 2004
published online 8 December 2004
In an elegant paper, Nelson suggested a method to produce tetravalent colloids based on a tetrahedral configuration created on the surface of a spherical particle. It emerges from a two-dimensional nematic liquid crystal placed on a sphere due to the presence of four 1/2 disclinations, i.e., topological defects in the orientational order (Nelson D. R., Nano Lett. 2 (2002) 1125). In this paper we show that such a tetrahedral configuration also occurs in the wetting layers which form around spheres dispersed in a liquid crystal above the nematic-isotropic phase transition. Nematic wetting therefore offers an alternative route towards tetravalent colloids.
82.70.Dd - Colloids.
61.30.Hn - Surface phenomena: alignment, anchoring, anchoring transitions, surface-induced layering, surface-induced ordering, wetting, prewetting transitions, and wetting transitions.
61.30.Dk - Continuum models and theories of liquid crystal structure.
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