A novel directional repairing rGO-Fe3O4/Oil coating with magnetic driving for metal protection and self-healing

Abstract Localized corrosion is caused by less protection of the metal substrate, which causes catastrophic damage for load-bearing material. It is significant to rescue corroded areas in a smart and controllable manner. Herein, a newfangled strategy for directional repairing rGO-Fe3O4/Oil coating drove by magnetic force to mitigate local corrosion was proposed. The new directional repairing system was consisted of low-viscosity oil and magnetically responded rGO-Fe3O4 filler via hydrothermal synthesis. Easy-flowing oil acted as the driving of the self-healing coatings because they can readily reconnect to heal minor flaw. Due to the synergistic effect of the magnetic responsiveness and the impermeability of rGO-Fe3O4, the flowable rGO-Fe3O4/Oil film can move to the corroded area under the action of magnetic field and effectively mitigated the corrosion examined by the scanning vibrating electrode technique (SVET). Moreover, the rGO-Fe3O4/Oil film was capable of repeating self-healing ability in air, pH = 1 (acid), pH = 7 (salt), and pH = 14 (alkali) solutions at the same area. The excellent anti-corrosion performance of rGO-Fe3O4/Oil coating was attributed to rGO-Fe3O4 tremendously improved its physical barrier effect and prolonged the penetration path of the corrosive mediums. Such a strategy could offer a potential approach for the preparation of anticorrosion materials that could accurately and intelligently repaired the localized corrosion on metal substrate.