Dual bioinspired superhydrophobicity and magnetically-induced self-healing ferrofluid-based SLIPS to inhibit corrosion of copper

Copper has extensive industrial applications. However, the susceptibility to corrosion makes it vulnerable in harsh environments. Bioinspired coating presents a novel approach to address copper corrosion. Bioinspired from lotus leaves and pitcher plants, this research endeavors to create superhydrophobic and ferrofluid-infused surfaces (FIS) on copper substrate. Firstly, a one-step electrodeposition method is employed to fabricate superhydrophobic surface on copper. Secondly, Fe 3 O 4 nanoparticles are sequentially modified with dopamine hydrochloride and dodecanethiol to endow surface hydrophobicity. Then, the modified Fe 3 O 4 is dispersed in oil to create a magnetic fluid, which is finally infused onto the superhydrophobic matrix, forming the FIS coating. Electrochemical testing confirms the high protective effect of the bio-inspired superhydrophobic and magnetic fluid composite coating against corrosion. The FIS coating exhibits a prominent low-frequency impedance modulus (7.73 × 10 6 Ω·cm²) even after immersion in NaCl solution for 60 d. Furthermore, the coating demonstrates an outstanding magnetic-driven self-healing capability, as evidenced by the minimal decrease in the |Z| 0.01 Hz value (remaining as high as 10 9 Ω·cm²) even after undergoing six cycles of scratching and self-healing process. This corrosion resistance can be attributed to the combined effects of the accommodating effect of superhydrophobic matrix and the self-healing property of the magnetic fluid under the magnetic field. This dually bio-inspired coating technology offers significant advantages for copper applications in harsh environments.