COMPUTER-SIMULATION OF THE LIQUID-VAPOR INTERFACE IN LIQUID-CRYSTALS

We present a computer simulation study of the liquid-vapour interface for a fluid characterized by anisotropic interactions. This model has been shown to be suitable for studying liquid crystal phases. In this work we focus on interfacial properties such as orientational effects at the interface and the dependence of the surface tension with temper ature. At all temperatures reported here, the liquid in coexistence wi th vapour is always orientationally disordered, although some evidence of smectic order at the lowest temperatures is observed. For the high er temperatures, no clear orientational effect is observed at the inte rface; however, as the temperature is decreased towards the vapour-iso tropic liquid-smectic triple point, molecules tend to orient themselve s at the interface. The surface tension values reported in this work s eem to be in qualitative agreement with the anomalous behaviour observ ed for this quantity in the vecinity of the triple point in liquid cry stals.