Influence of reduced graphene oxide content on dielectric, optical energy band gap, and I–V characteristics of PVDF/PANI/RGO nanocomposites

This analysis explores the significant enhancement in dielectric performance, I–V characteristics, optical energy band gap and thermal properties of reduced form graphene oxide (RGO) based poly (vinylidene fluoride) (PVDF)/polyaniline (PANI) blend nanocomposites. The dispersion pattern of RGO and PANI phases in the bulk of PVDF has been analyzed from the photomicrographs obtained from the high-resolution transmission electron microscopy studies. The effect of ionic liquid (IL) such as 1-Butyl-3-methylimidazolium hexa-fluoro phosphate on the dispersion pattern of the PANI and RGO phases in the interface has also been analyzed from the photomicrographs obtained. The informative morphology recorded for the fabricated nanocomposite systems is correlated with the dielectric relaxation performance, optical energy band gap, and I – V characteristics. The excellent dielectric properties such as high dielectric permittivity ( ε′ ), adequate AC conductivity ( σ ac ), and required impedance (both real and imaginary) of the fabricated conductive nanocomposite systems have been explored in a wide range of frequencies (1 to 10 6 Hz) of the applied electric field. The effects of IL on the above dielectric properties are also explored and the result obtained particularly for ε′ in presence of IL ensures the effortless polarization of the dipoles. The non-linear I – V characteristics behavior indicates the disordered structure of crystalline RGO and PANI nano particulates separated by insulating and semicrystalline PVDF matrix. The shifting of the optical energy band gap towards lower photon energy on increasing the addition of RGO loading level obtained from the optical energy band gap study reveals the alteration of energy states in between the conduction band and valence band upon 0.25 wt% of RGO incorporation. The effect of RGO and IL on the thermal stability of developed nanocomposites has been explored using thermal analysis. The dielectric properties reveals the suitability of the systems for electromagnetic shielding applications.