Autonomous self-healing super-hydrophobic anti-corrosion coating based on confined flow of deep eutectic solvent

The autonomous intrinsic self-healing of coatings is frequently constrained by challenge of achieving spontaneous contact at damaged interfaces, posing significant obstacles for anti-corrosion coatings in harsh environments where timely repair is not feasible. The emerging solid-liquid composite design strategy shows promise by integrating of liquid-like materials within a solid matrix to enhance flowability, thereby promoting spontaneous contact at damaged interfaces. In this study, we developed a dynamic disulfide bond-based epoxy resin network (EP-SS) as the "fixed matrix" to encapsulate a highly adjustable deep eutectic solvent (DES) as the "fluid phase", forming a self-healing bottom layer. This innovative design enables molecular-level "confined flow" of DES, driving the EP-SS network towards defects and facilitating rapid self-healing within 30 min at room temperature. The "confined flow" of DES within the polymer network is substantiated by experimental validation and theoretical calculations. Additionally, a superhydrophobic SiO2/PDMS/EP top layer is developed, forming a bilayer SiO2@EP-SS/DES coating that exhibits excellent self-healing ability at room temperature, underwater durability, and long-term corrosion resistance.