The effect of spherical additives on a liquid crystal colloid

We present a computer simulation study of a colloidal particle immersed in a solvent comprising liquid crystalline rod-shaped particles and a 10% number concentration of small spherical additives. The presence of the colloidal particle (and its periodic images) is found to induce qualitative changes in the phase behaviour of the rod-sphere mixture. When the colloidal particle favours radial anchoring, it is found that the small spheres spontaneously aggregate to form a droplet which resides in the equatorial plane of the colloidal particle. When the colloidal particle favours tangential anchoring, however, the small spheres aggregate to form droplets at each of the boojums seen experimentally. These findings confirm expectations that small additives to liquid crystalline systems should preferentially reside in disordered regions, whilst also reflecting the competing influence of surface tension effects.