Consequences of Flexoelectricity on Director Distribution and Local Mass Density Fluctuation in Parallel Aligned Nematic Liquid Crystals

In this paper, considering the flexoelectric effect, the coupling consequences of local mass density fluctuation and liquid crystal director distribution are analyzed in parallel aligned nematic liquid crystals. Under the applied surface free charge density, the total free energy of liquid crystal system includes the elastic energy, local density energy density, flexoelectric energy and dielectric energy using the director-density coupling theory. Then the Ginzburg-Landau phase field equation of the liquid crystal director evolution and Cahn-Hilliard equation of the local mass density change are established to couple the evolution process and final distribution of the director and local mass density. The distribution curves of liquid crystal director, local mass density are calculated and illustrated. The effects of surface free charge density and material parameters have been discussed in detail. The results show that the Freedericksz transition accompanied by a modulation in the mass density.