Atomistic modelling of liquid-crystal surface modificationM. T. Downton1, 2 and S. Hanna1
1 H. H. Wills Physics Laboratory, University of Bristol - Tyndall Avenue Bristol, BS8 1TL, UK
2 Physics Department, Simon Fraser University - Burnaby B.C., V5A 1S6, Canada
received 4 September 2005; accepted in final form 14 February 2006
published online 8 March 2006
Results are shown from atomistic molecular-dynamics simulations of 800 5CB molecules in contact with a graphite substrate, onto which flexible alkyl chains have been tethered. By increasing the number density of tethered chains, it is shown that the alignment switches from planar to homeotropic. The change of anchoring is accompanied by a change in the conformation of the tethered chains, which switch from being bound close to the substrate at low densities, to being almost fully extended and parallel to the liquid-crystal moieties at high densities.
61.30.Hn - Surface phenomena: alignment, anchoring, anchoring transitions, surface-induced layering, surface-induced ordering, wetting, prewetting transitions, and wetting transitions.
61.20.Ja - Computer simulation of liquid structure.
© EDP Sciences 2006