MONTE-CARLO STUDY OF GAY-BERNE LIQUID-CRYSTAL DROPLETS

We report results of a series of NVT Monte Carol simulations on system s of molecules interacting via a Gay-Berne (GB) potential within a sph erical cavity modelling a polymer-dispersed liquid-crystal (PDLC) drop let. The cavity walls have been simulated by constructing a spherical shell of GB particles, each oriented towards the centre of the drop in an attempt to promote radial boundary conditions. The wall-fluid inte ractions have been modelled with a modified 1-3 GB potential (with ene rgy exponents mu-1 and nu = 3, respectively) to favour radial alignmen t. We show results for the molecular organization in the droplet for a 2-1 and 1-3 fluid-fluid potential. We also show the radial order para meter as a function of temperature and droplet size. It is found that at low scaled temperatures a layer of radially aligned particles is fo rmed, but this ordering does not propagate towards the centre of the d rop unless the drop is relatively large or all the fluid-fluid interac tions are modelled with the 1-3 potential. In this situation, concentr ic shells of aligned particles are formed, with a small smectic-like d omain in the centre.