Thermal and Electro-optical Properties of Graphene Oxide/Dye-Doped Nematic Liquid Crystal

In this paper, the liquid crystalline complex systems were obtained by dispersing graphene oxide (GO) and methyl blue (MB) dye to liquid crystal mixture E7. The phase transitions and microstructural properties of the prepared liquid crystalline complex systems were investigated by differential scanning calorimeter (DSC) and polarised optical microscopy (POM). DSC and POM results showed that there was no change in the molecular structures of the complexes and they exhibited completely liquid crystalline properties during continuous heating. Also, the voltage-dependent optical transmissions of the complex systems were measured by the voltage transmittance experiments. It was found that the optical transmissions of the complex systems were not very different from the each other, but threshold voltage of the complex decreased by GO doping and increased for MB/GO doping. Furthermore, the dielectric properties of the complex systems were investigated by using impedance analyser. Dielectrically, measurements showed that the dielectric constant decreased with the dispersion of GO and GO/MB, and the critical frequency of E7 increased with doping.