Surface Energy‐Driven Microphase Separation Enables Self‐Healing Core‐Shell Coating With Enhanced Mechanical and Anticorrosion Performance

ABSTRACT A multifunctional epoxy‐based coating integrating mechanical robustness, autonomous self‐healing, and corrosion resistance has been fabricated via surface energy‐mediated phase separation. The core‐shell microstructures, formed through spontaneous self‐assembly driven by surface energy gradient‐induced phase separation during epoxy coating curing, consist of aromatic petroleum resin (APR) cores enveloped by graphene (Gr) shells, which are homogeneously distributed within the epoxy matrix. Upon mechanical fracture, rapid release of APR from the damaged microcapsules enables efficient crack repair. Synergistic integration of 1H‐benzotriazole (BTA) corrosion inhibitor establishes sustained release kinetics, significantly enhancing barrier functionality. The composite exhibits exceptional mechanical performance, achieving a tensile strength of 24.93 MPa, a 2.6‐fold increase over conventional epoxy coatings, due to optimized stress transfer through graphene‐reinforced interfacial networks. Electrochemical characterization confirmed long‐term corrosion protection, maintaining |Z| 0.01Hz = 1.09 × 10 10 Ω cm 2 after 14 weeks of immersion in 3.5 wt% NaCl solution. This surface energy‐controlled core‐shell architecture represents a universal design paradigm for advanced protective coatings.