Mussel Cuticle Granule-Inspired Nanocomposite Coating Derived from Metal-Organic Frameworks for Intelligent Corrosion Control
Superhydrophobic coatings that physically separate metal substrates from aqueous media have emerged as a promising strategy against metal corrosion; however, their practical application is hindered by poor mechanical durability and rapid performance degradation in harsh environments. Herein, inspired by the granular architecture and dynamic metal coordination chemistry in mussel byssus cuticle, a hierarchical metal coordination-mediated self-adaptive coating (SC) integrating surface superhydrophobicity, self-healing anticorrosion, and damage-monitoring capacity is constructed on steel substrates using a metal-organic framework (MOF) as the multifunctional nanoplatform. Specifically, a MOF-polydopamine nanocomposite coating is fabricated on mild steel via a coordination-dissociation-polymerization mechanism, where the MOF serves as a self-sacrificial template to initiate the deposition of polydopamine, and the SC is obtained after subsequent hydrophobization via Michael addition and Schiff base reaction. The superhydrophobic surface of SC with a water contact angle of 160° provides a superior passive barrier against corrosive media, showing a protective efficiency of 97.5%. Furthermore, the MOF-polydopamine interlayer endows the SC with superior corrosion-triggered self-healing properties by forming protective adsorption films at the exposed steel surface, thereby preventing rapid failure of the SC caused by mechanical damage. Additionally, the photothermal properties of the polydopamine moieties generate a rapid temperature gradient upon light exposure, allowing early-stage damage detection through infrared thermography. This work presents a biomimetic strategy for developing intelligent anticorrosion coatings that combine superhydrophobicity, self-repair, and real-time damage sensing, advancing the application of MOF-derived materials in protective coatings.