NUMERICAL-CALCULATION OF NEMATIC DIRECTOR FIELDS WITH STOCHASTIC INNER BOUNDARIES

The reorientation behaviour of a nematic liquid crystal restricted to thin planar cells in external electro-magnetic fields is well known. W e discuss the effects of external fields on a bulk sample where a pref erred director alignment is achieved by oriented small solid particles statistically dispersed in the nematic. The calculations may serve as a model for LC/polymer gels. They allow for the determination of phys ical properties, e.g. mesh sizes, from dielectric, optical or NMR meas urements. A threshold behaviour for the director is found from the cal culations. Critical fields, director distribution functions and charac teristic relaxation times are derived.