Autonomous Self‐Healing Anti‐Corrosion Coating Enabled by Synergy of Hydrophobic Deep Eutectic Solvent and Elastic Resin

Abstract Self‐healing of coating damage is highly desirable for long‐term corrosion protection. However, achieving intrinsic autonomous self‐healing often involves a trade‐off, as increased molecular mobility can compromise coating stability and corrosion resistance, particularly in harsh, water‐rich environments. Herein, a robust anti‐corrosion coating with remarkable autonomous self‐healing ability is presented. By integrating a hydrophobic deep eutectic solvent (HDES) into a disulfide bond‐crosslinked siloxane‐modified epoxy resin (SiEP‐SS), the SiEP‐SS/HDES 40 (40 wt.% HDES) coating achieves rapid self‐healing within 1 h in both atmospheric and underwater environments. This remarkable performance arises from the synergy between the SiEP‐SS matrix elasticity (elastic recovery ratio W e = 71.4%) and the confined flow of HDES, which together promote crack closure and damage‐interface reconnection. The coating demonstrates outstanding corrosion resistance and long‐term durability, withstanding 1000 h of salt spray testing, enabled by hydrophobic interactions within the SiEP‐SS/HDES network. Molecular dynamics simulations reveal the critical roles of HDES mobility and hydrophobic interactions in promoting interfacial healing. The SiEP‐SS/HDES coating exhibits significant scalability without performance degradation, providing a robust solution for corrosion protection and laying the foundation for designing DES‐based advanced protective coatings with autonomous self‐healing ability.