Monte Carlo simulation of two-dimensional dimers between hard walls

Abstract

Monte Carlo simulation is used to examine the bulk equation of state and site-density profiles of a two-dimensional fluid of hard dimers between two hard walls. Dimers are modelled by two, tangent, hard discs and the pressure is calculated from the density of discs in contact with the walls. Five state points are examined at area fractions ranging from 0·1133 to 0·4950 and the results compared to several theoretical equations of state. Excellent agreement is obtained, over the entire density range, using an equation recently developed by Boublik. Very good agreement is also obtained with the generalized Flory-Huggins equation, which we derive here for two-dimensional athermal chain molecules. At low densities the site-density profile near the wall is depleted, while at higher densities it is enhanced.