Synthesis of polyaniline-modified graphene oxide for obtaining a high performance epoxy nanocomposite film with excellent UV blocking/anti-oxidant/ anti-corrosion capabilities

This paper focuses on the synthesis and modification of graphene oxide nanosheets with polyaniline. The main aim is to take the advantages of both graphene oxide and polyaniline in enhancing the long-term performance (including weathering and corrosion) of exterior nanocomposites. For this purpose, the synthesized graphene oxide was treated via an in-situ polymerization process. The modified hybrid nanosheets were characterized by Fourier transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FE-SEM), X-ray diffraction analysis (XRD), Ultraviolet–visible spectrophotometry (UV–Vis) and Raman spectroscopy. It was approved that the emeraldine base form of polyaniline has been successfully polymerized on the graphene oxide nanosheets in two forms of non-covalent bonding through π-π interactions between quinoid ring of PANI and basal plane of graphene oxide, and covalent bonding through reaction with epoxide group. The modified nanosheets were introduced into a typical epoxy matrix and then subjected to accelerated weathering and corrosion cycles. The results revealed that a considerable improvement in both weathering (42% reduction in ΔE) and corrosion resistance was achieved which was mainly attributed to the considerable enhancement in UV shielding, radical scavenging as well as better dispersion of graphene oxide modified with polyaniline.