Tetravalent colloids by nematic wetting

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

Corresponding author: Holger.Stark@uni-konstanz.de

Received: 23 July 2004
Accepted: 2 November 2004

Abstract

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.