Doping liquid crystals with nanoparticles. A computer simulation of the effects of nanoparticle shape

Abstract

We have studied, using Monte Carlo computer simulations, the effects that nanoparticles of similar size and three different shapes (spherical, elongated and discotic) dispersed at different concentrations in a liquid crystal (LC), have on the transition temperature, order parameter and mobility of the suspension. We have modelled the nanoparticles as berry-like clusters of spherical Lennard-Jones sites and the NP with a Gay–Berne model. We find that the overall phase behaviour is not affected by the addition of small amounts (x_N = 0.1–0.5%) of nanoparticles, with the lowest perturbation obtained with disc-like nanoparticles at the lowest concentration. We observe a general decrease of the clearing temperature and a reduction in the orientational order with a change in its temperature variation, particularly in the case of the x_N = 0.5% dispersions and with a more pronounced effect when the nanoparticles are spherical.