Polymeric Microcapsules with Sustainable Core and Hierarchical Shell toward Superhydrophobicity and Sunlight-Induced Self-Healing Performance

Photopolymerization is considered as one of most promising candidates for microcapsules-embedded self-healing system due to its significant advantages, e.g., fast, energy efficient and commonly economical. However, many microencapsulated photopolymerizable healing agents are usually expensive, unsustainable, or even environmentally hazardous. Herein, a polymeric microcapsule with hierarchical shell and low-cost, sustainable epoxidized soybean oil (ESO) as main core material was prepared through in situ polymerization in oil-in-water emulsion. Mean diameter of microcapsules versus agitation rate is exponential decay and linear in double logarithm coordinates, indicating their structure can be controlled effectively. ESO-based core materials are photopolymerizable under air upon sunlight or xenon lamp irradiation. Microcapsules-embedded epoxy coatings possess sunlight-induced self-healing anticorrosion. Besides, microcapsules have a good thermal stability, a long-term storage stability and a superior tolerance for attacks of light and water. Thanks to micro-/nanohierarchical structure on their surface resembling a lotus leaf, microcapsules have a superhydrophobicity and microcapsules-bound coatings exhibit a self-cleaning property.