Ultralong-Term Durable Anticorrosive Coatings by Integration of Double-Layered Transfer Self-Healing Ability, Fe Ion-Responsive Ability, and Active/Passive Functional Partitioning

The application of self-healing polymers in corrosion protection is often limited by their slow and nonautonomous healing ability and poor long-term durability. In this paper, we propose a double-layered transfer self-healing coating constructed by soft and rigid polymer layers. The soft polymer has a fast self-healing rate of 10 min to repair, which was found to accelerate the self-healing of the upper rigid layer. The rigid polymer provided relatively high barrier ability while preserving certain self-healing ability owing to the shear-thinning effect. In this way, the double-layered coating combined rapid self-healing (∼1 h) and high impedance modulus |Z|f-0.01 Hz of 2.58 × 1010 Ω·cm2. Furthermore, the introduction of pyridine groups in B-PEA and polyacrylate-grafted-polydimethylsiloxane (PEA-g-PDMS) induced the Fe ion-responsive ability and shortened the self-healing time to 40 min (100 ppm Fe). Finally, barrier and anode sacrificed layers were introduced to produce multilayered architecture with active/passive anticorrosion performance. In the presence of scratches, the |Z|f-0.01 Hz can be preserved at 1.03 × 1010 Ω·cm2 after 200 days. The created anticorrosive coating technology combines long-term durability with room temperature autonomous rapid self-healing capability, providing a broad prospect for anticorrosive applications.