A Molecular Simulation of A Liquid-crystal Model

A Gay-Berne fluid of prolate molecules with length-to-breadth ratio 3 is studied using molecular dynamics simulations. This fluid exhibits vapor, isotropic liquid, nematic, and smectic-B mesophases. For the bulk fluid we report new results along isochores that further delineate the smectic and nematic regions of the phase diagram; the effect of system size is also discussed. These studies lead to a rather complete description of the fluid part of the phase diagram. We have also studied the changes that occur when such a fluid is confined in a pore with parallel, homeotropic walls. Our molecular dynamics results show that the isotropic-nematic transition shifts to higher temperatures, or lower densities, i.e., the liquid crystal phase is stabilized relative to the bulk flild.