Europhys. Lett.
Volume 74, Number 6, June 2006
Page(s) 1039 - 1045
Section Condensed matter: structural, mechanical and thermal properties
Published online 17 May 2006
Europhys. Lett., 74 (6), pp. 1039-1045 (2006)
DOI: 10.1209/epl/i2006-10062-4

Hard colloidal rods near a soft wall: Wetting, drying, and symmetry breaking

K. Shundyak1 and R. van Roij2

1  Instituut-Lorentz for Theoretical Physics, Leiden University - Niels Bohrweg 2 Leiden, NL-2333 CA, The Netherlands
2  Institute for Theoretical Physics, Utrecht University - Leuvenlaan 4 3584 CE Utrecht, The Netherlands

received 23 January 2006; accepted in final form 26 April 2006
published online 17 May 2006

Within an Onsager-like density functional theory we explore the thermodynamic and structural properties of an isotropic and nematic fluid of hard needle-like colloids in contact with a hard substrate coated with a soft short-ranged attractive or repulsive layer. As a function of the range and the strength of the soft interactions we find wetting and drying transitions, a pre-drying line, and a symmetry-breaking transition from uniaxial to biaxial in the wetting and drying film.

61.30.Hn - Surface phenomena: alignment, anchoring, anchoring transitions, surface-induced layering, surface-induced ordering, wetting, prewetting transitions, and wetting transitions.
64.70.Md - Transitions in liquid crystals.
05.70.Np - Interface and surface thermodynamics.

© EDP Sciences 2006