Preparation of pH responsive smart nanocontainer via inclusion of inhibitor in graphene/halloysite nanotubes and its application in intelligent anticorrosion protection

Abstract

Graphene exhibits great potential as a functional building block in modern protective material aiming to high anti-corrosion performance. Herein, we demonstrate a concept for graphene based integrated intelligent inhibitor nanocontainer (IIIN), which can provide multifunctional anti-corrosion protection when be applied as a modifier in waterborne coating. The synthesis of IIIN was started from the nanocomposite of halloysite nanotubes (HNTs) and reduced graphene oxide (rGO). Then, L-histidine (L-His) was loaded on HNTs-rGO for the formation of ternary nanocomposite via electrostatic adsorption. IIIN has the excellent compatibility with waterborne coatings. Importantly, L-His@HNTs-rGO can provide an integrated anticorrosion function: in addition to the role of “passive protection” of rGO, IIIN not only extends the diffusion distances of the corrosive molecules, interrupts the possible formation of conductive pathways, but also serves an intelligent container to release L-His. The comprehensive result is the effective prolongation on the protection life of the coating from 7, 67 and 22 days of the unmodified waterborne coating, to 42, 116, and 69 days of the IIIN modified coating in H2SO4, NaOH, NaCl solution respectively. The electrochemical impedance spectroscopy (EIS) has been applied to monitor the corrosion process for different coatings, which confirms the synergism effect of IIIN.