A smart self-healing coating utilizing pH-responsive dual nanocontainers for corrosion protection of aluminum alloy

Abstract

In this study, a novel smart self-healing coating was developed for aluminum alloy surfaces using chitosan and mesoporous ZSM-5 molecular sieve as dual nanocontainers. These nanocontainers effectively address the challenges of limited loading capacity and uncontrolled release of corrosion inhibitors by offering pH-responsive properties that enable complementary release in both acidic and alkaline environments. The synthesized coating exhibited excellent anticorrosion and self-healing performance, as demonstrated by a corrosion inhibition efficiency of 99.98 % after 36 h of static corrosion and significant improvements in impedance values at defect sites. The self-healing mechanism is primarily driven by the formation of Ce(OH)₃ and CeO₂, which precipitate and accumulate at the corrosion sites, thereby preventing further degradation. This study highlights the potential of pH-responsive dual nanocontainer-based coatings for enhancing the durability and protection of aluminum alloys in corrosive environments.