Dielectric Properties of Graphene Oxide-doped Nematic Liquid Crystal

Introduction: Graphene and Graphene oxide (GO) at the nanoscale are remarkable nanomaterials with a variety of astonishing properties. The dielectric properties of the thermotropic nematic (5CB) liquid crystals with dispersed GO have been experimentally studied. The real and imaginary parts of dielectric permittivities were measured both in the lyotropic and thermotropic nematic phases. Methods: The dielectric properties of graphene oxide-doped nematic liquid crystal are studied using the combination of Flory-Huggins theory and Landau-de Gennes theory. The real and imaginary parts of the permittivity as a function of temperature, frequency, and concentration of graphene oxide in the nematic phase are calculated. Results: The real and imaginary parts of the dielectric permittivities are plotted for different frequencies for graphene oxide-doped nematic liquid crystal. An immense impact has been found in the dielectric permittivity in the graphene oxide-doped nematic liquid crystal. The dielectric permittivity decreases with the increase of frequency and increases with the increase of temperature. Discussion: The increase of dielectric permittivity with temperature in the NLC+GO mixture occurs due to the strong interaction between GO and NLC molecules. The strong rise appears when the frequency is lowered. This indicates the rising impact of translational processes. Conclusion: The dielectric properties of the GO-doped NLC are studied theoretically. The temperature, frequency, and concentration dependence of the real and imaginary parts of the dielectric permittivity of the GO-doped NLC are calculated. An appreciable change in the dielectric permittivity has been observed for the NLC+GO mixture. A good qualitative agreement between the theoretical and experimental results has been observed.