GRAPHENE NANOCOATING RENDERS PERSISTENT CORROSION PROTECTION TO TITANIUM BIOMEDICAL ALLOYS

Abstract

Presence of metallic nanoparticles around healthy and failed dental implants have raised concerns on biomedical titanium alloy stability. Previous strategies to address this issue have limited functionality in resisting electrochemical- and bio-corrosion. Graphene is an atom-thick carbon layer, with excellent properties and biocompatibility. Its small pore size and electrically repulsive dense pi-orbitals makes it highly impermeable. Exploring this property, graphene nanocoating’s anti-corrosion potential has been tested in fluoride containing acidic medium. A comprehensive investigation over a prolonged period of corrosive challenge has been studied. Finally, microbiologically influenced corrosion resistance of graphene was tested after Streptococcus mutans biofilm exposure. Detailed structural, elemental, and electrochemical characterization of uncoated controls and graphene nanocoated samples exposed to corrosion conditions were performed. The results demonstrated superior structural and surface elemental integrity offered by graphene nanocoated samples. The polarization sweeps and electrochemical impedance spectroscopy further confirm lower anodic dissolution and higher anti-oxidation potential of graphene samples.