π-π interaction between fluorinated reduced graphene oxide and acridizinium ionic liquid: Synthesis and anti-corrosion application

Graphene has long been considered a superlative protection material due to its extraordinary characteristics and properties. However, its high electrical conductivity can facilitate the electrochemical corrosion of metal, which strongly limits its anti-corrosion applications. Here, we developed a facile fluorination strategy to suppress the corrosion promotion activity of graphene. Fluorinated reduced graphene oxide (FrGO) exhibited low electrical conductivity (3.643 x 10(-13) S/cm), which proved unable to trigger micro-galvanic corrosion. Furthermore, acridizinium ionic liquid (IL) [MAc]Br was non-covalently grafted on FrGO to achieve the well dispersion in the polymer matrix. Results revealed that FrGO-IL nanohybrid can be stably dispersed in the epoxy resin. Electrochemical impedance spectroscopy revealed that incorporating a small percentage of FrGO-IL into waterborne epoxy matrix effectively improved the corrosion resistance performance of the coating by exerting the superior shielding effect and inhibiting the ability for micro-galvanic corrosion. Moreover, local electrochemical and scratching tests further confirmed that FrGO-IL significantly reinforced the corrosion protection capability of waterborne epoxy coating because the well-dispersed nanohybrid enhanced the integrity of the composite coating, effectively utilizing the labyrinth effect. Our finding could inspire the development of new graphene-based materials with superior protection properties for metal materials. (C) 2019 Elsevier Ltd. All rights reserved.