Evaluation of reduced graphene oxide/ZnO effect on properties of PVDF nanocomposite films

In this work, we report the preparation and characterization of PVDF/reduced graphene oxide (RGO)-ZnO nanocomposite films via synthesis of reduced graphene oxide-ZnO nanocomposite by solution casting method. Different weight ratios of RGO-ZnO nanocomposites were produced and compounded with PVDF by solution mixing. The compounding was followed by solution casting and drying to form nanocomposite films. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction techniques (XRD), revealed an obvious α to β-phase transformation compared to pure PVDF which a maximum content of 83% for β-phase was calculated by using FTIR techniques. The morphology of the nanocomposites was investigated using scanning electron microscope (SEM). SEM micrographs showed a decrease in size of spherulitic crystal structure of PVDF/RGO-ZnO nanocomposites compared with pure PVDF which has an obvious relation with β-phase enhancement. The thermal behaviors of PVDF/RGO-ZnO nanocomposite films have been investigated by employing thermogravimetric analysis (TGA). Since the interface between PVDF and the nanoparticles has an important role in the nucleation of the polymer phase, thermogravimetric analysis was used in order to identify and quantify the interface region and to correlate it with the β-phase content. It is found that an intimate relation exists between the size of the interface region and the piezoelectric β-phase formation that depends on the RGO-ZnO content. The interface value and the β-phase content increase with increasing RGO-ZnO. The PVDF nanocomposites showed higher thermal stability than the pure polymer.