Electrical properties of the octyl cyanobiphenyl nematic liquid crystal dispersed with graphene oxide

Abstract

Graphene oxide (GO) with different concentrations was dispersed to pristine octyl cyanobiphenyl nematic liquid crystal. The characteristics of the used GO were investigated with X-Ray diffraction (XRD), scanning electron microscopy (SEM) and UV–Vis spectroscopy. Also the bandgap values of GO were calculated. The impact of doping concentration on the thermal and electrical properties of prepared samples was investigated. The phase transition temperatures of samples were studied by differential scanning calorimeter. The isotropic phase transition temperature has decreased by the addition of graphene oxide ratio in samples. The electrical properties of the samples have been examined by measuring dielectric permittivity, capacitance and impedance of samples with an impedance analyzer. Also, electrical behaviors of pure and GO-dispersed samples under bias voltage were studied. The relaxation frequencies of specimens were obtained. The dielectric anisotropy and relaxation frequency also increased due to the presence of graphene oxide flakes. The dielectric permittivity $${\varepsilon }^{^{\prime}}$$ of GO-dispersed samples enhanced under the bias voltage was revealed.