Triple-Barrier Superamphiphobic Coatings Based on Lamellar Metal–Organic Framework/Epoxy Composites for Durable Corrosion Protection of Magnesium Alloys

Durable superamphiphobic coatings for Mg alloys remain elusive due to the inherent trade-off between mechanical robustness, environmental stability, and corrosion resistance. This study resolves this challenge through synergistic integration of fluorinated lamellar ZIF-7 microparticles and epoxy resin (EP), representing a pioneering application of metal-organic frameworks (MOFs) in superamphiphobic anticorrosion coatings. Solvothermally crystallized ZIF-7 undergoes functionalization via ligand exchange and thiol-ene click reactions, achieving superamphiphobicity (WCA: 168.9°, OCA: 167.2°, SA: 2°). Strategic EP incorporation preserves particle-derived ″labyrinth effects″ while enhancing mechanical interlocking, enabling triple-barrier effects (labyrinth diffusion, fluorinated passivation, mechanical interlock) that yield a composite coating with exceptional performance: dynamic self-cleaning against aqueous/oily contaminants and dust, excellent barrier integrity with initial |Z|_{0.01 Hz} = 2.25 × 10¹⁰ Ω·cm² sustaining >10⁹ Ω·cm² after 30 days of immersion, which is 4 orders of magnitude higher than that of the pure EP coating, mechanical durability maintaining WCA/OCA > 150° after 30-cycle abrasion under 200 g load on 800-grit sandpaper, and chemical stability retaining superamphiphobicity for 5 days in 1 M HCl, 10 days in 1 M NaOH, and 60 days in 3.5 wt % NaCl. This MOF-epoxy paradigm overcomes the long-standing trade-off through triple-barrier synergy, establishing a novel strategy that expands MOF functionality beyond traditional applications to next-generation anticorrosion coatings with significant implications for aerospace, marine engineering, and sustainable materials development.