This study introduces a robust, self-healing superhydrophobic coating for magnesium (Mg) substrates, leveraging the synergistic effects of MQ organosilicon polymer, octadecylamine (ODA), polydopamine (PDA), and copper-loaded graphene oxide (GO). The coating exhibits exceptional superhydrophobicity, outstanding stability in harsh environments, superior resistance to smudging, and effective self-cleaning capabilities. Electrochemical impedance spectroscopy (EIS) in 3.5 wt % NaCl solution demonstrates an impedance modulus (|Z|) at f = 0.01 Hz and polarization resistance (Rp) of 3.49 × 108 Ω cm2 and 3.88 × 108 Ω cm2, respectively, 7 orders of magnitude higher than AZ31B. After 35 days of immersion, |Z|f=0.01 Hz and Rp remain at 3.97 × 107 Ω cm2 and 4.63 × 107 Ω cm2, respectively, highlighting long-term corrosion protection. In cases of damage or corrosion, the dynamic coordination of PDA-Cu2+ enables self-healing, fully recovering visible coating defect up to 10 μm in width within 24 h in 3.5 wt % NaCl solution. This work presents a promising approach for durable, self-healing superhydrophobic coatings with exceptional mechanical and chemical stability.
Yu et al. (Fri,) studied this question.