MONTE-CARLO SIMULATION OF THE NEMATIC-VAPOR INTERFACE FOR A GAY-BERNELIQUID-CRYSTAL

The nematic-vapour interface of the Gay-Berne liquid crystal model has been studied by Monte Carlo simulation. When the anisotropy parameter kappa' is set to 1.25, a film of particles in a rectangular box has b een shown to exhibit nematic-vapour coexistence. Analysis of the orien tational ordering across the sample reveals that the anchoring is plan ar, that is, the preferred alignment is in a direction parallel to the interface. No nematic wetting of the film in the isotropic phase is o bserved, although there is a strong tendency for the molecules near th e surface to be parallel to the interface even at temperatures higher than the isotropic-nematic-vapour triple point. (C) 1997 Published by Elsevier Science B.V.