Thermal stability and dielectric relaxation behavior of in situ prepared poly(vinyl alcohol) (PVA)-reduced graphene oxide (RGO) composites

Poly(vinyl alcohol) (PVA)-reduced graphene oxide (RGO) composite films have been prepared via in situ reduction of graphene oxide (GO) inside PVA matrix. In order to study microstructure and morphology of prepared PVA-RGO composite films, transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) spectroscopy, UV-Visible absorption spectroscopy, X-ray diffraction (XRD) technique, and Raman spectroscopy were utilized. Thermogravimetric analysis (TGA) depicts the increase in thermal stability of PVA with increasing loading of RGO. The dielectric properties of composites were explored in frequency range 100 Hz–2.5 MHz which depicts increase in dielectric permittivity and ac conductivity of composite films with increasing RGO loading. The dielectric relaxation behavior and dispersion parameters of composite films were analyzed using Cole-Cole plots using a MATLAB program based on the Havrilak-Negami (HN) model.