Statistical Mechanics of a Simple Model of the Nematic Liquid Crystal-Wall Interface

Abstract

The orientational profile near a liquid-wall interface has been studied, concentrating, in the spirit of recent theories of wetting, on the existence of surface phase transitions. The Maier-Saupe theory has been used to investigate the behaviour of a nematic near a wall in the presence of both bulk and surface ordering fields. We find that the surface ordering transition predicted by Sheng is extremely sensitive to the form of the bulk nematic free energy. The surface transition is also dependent on the bulk ordering field, and terminates at a wetting temperature; it is symptomatic of prewetting behaviour and occurs near a wide variety of first order phase transitions. The surface adsorption, contact angle at a nematic-isotropic-solid contact line, and surface free energy as a function of bulk field and temperature are also studied.