Cyclodextrin, with a hydrophobic inner cavity and a hydrophilic exterior, is often used to encapsulate a widest range of guest molecules based on host-guest inclusion interactions. Graphene, an emerging nanobuilding material, exhibits great potential for numerous applications because of its superior characteristics. Herein, we synthesized a novel graphene/β-cyclodextrin-based supramolecular nanocontainer with excellent inhibitor encapsulating capacity and high impermeable properties. The benzotriazole (BTA)-loaded nanocontainers were then used to endow coating system with excellent passive and active anticorrosion performance. Local electrochemical impedance spectroscopy (LEIS) was performed to characterize the self-healing behavior of composite coatings. Results indicated that the protective capability of the scratched coatings can be recovered through BTA release from containers. Furthermore, the long-term corrosion resistance of container-based coating was largely improved as observed from EIS. The effective healing process involves two conditions: (1) the release of BTA from containers and formation of adsorption layers on exposed metal surfaces and (2) the impermeable graphene nanosheets greatly impeded the electrolyte penetration and corrosion extension around the scratch. This novel graphene/β-cyclodextrin-based nanocontainer endows polymer coating with efficient self-healing functionality and durable anticorrosion property.
Keywords: anticorrosion; graphene; nanocontainers; self-healing; β-cyclodextrin.