Design and Development of Dual‐Function Nano‐<scp>CeO₂</scp>‐Integrated <scp>PUF</scp>/Epoxy Microcapsule Systems for Self‐Healing and Corrosion‐Resistant Epoxy Coatings

ABSTRACT A dual‐function microcapsule system was developed to overcome the limitations of single‐mechanism self‐healing coatings. Nano‐CeO 2 particles were embedded in a polyurea formaldehyde (PUF) shell, with epoxy resin encapsulated inside. SEM, FTIR, and XRD characterization confirmed the successful integration of CeO 2 and epoxy within the microcapsules. These microcapsules were incorporated into an epoxy resin‐based coating at varying weight percentages to assess their impact on coating performance. EIS was employed to evaluate the self‐healing properties of coatings with artificial scratches in simulated seawater. When the coating is damaged, CeO 2 is released and deposited on the metal surface, rapidly forming a passivation film that protects the substrate in advance. CeO 2 also releases cerium ions. A cerium hydroxide precipitate is formed by reacting with OH − produced in the cathode region. Prevents penetration of corrosive ions. Meanwhile, the microcapsules rupture, releasing epoxy resin to heal the cracks. Electrochemical Impedance Spectroscopy (EIS) results demonstrated that the optimal self‐repair performance was achieved with 10 wt% microcapsules, while higher concentrations negatively affected the coating's adhesion. This dual‐function microcapsule approach significantly improves both protective and self‐healing capabilities, offering potential for advanced corrosion‐resistant coatings.