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 micro encapsulated 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.