A versatile approach towards multifunctional robust microcapsules with tunable, restorable, and solvent-proof superhydrophobicity for self-healing and self-cleaning coatings

Numerous microencapsulation techniques have been developed to encase various chemicals, for which specific processing parameters are required to address the widely differing features of the encapsulated materials. Micro-encapsulation of reactive agents is a powerful technique that has been extensively applied to self-healing materials. However, the poor solvent compatibility and insufficient thermal stability of microcapsules continue to pose challenges for long-term storage, processing, and service in practical applications. Here, an easily modifiable and highly versatile method is reported for preparing various chemicals filled poly(urea-formaldehyde) microcapsules that exhibit superior tightness against solvents and heat and that possess widely tunable, repetitiously self-restorable, and solvent-proof superhydrophobicity. In addition, the low-cost fabrication of biomimetic multifunctional smart coatings is demonstrated for self-healing anticorrosion and selfcleaning antifouling applications by directly dispersing the superhydrophobic microcapsules into and onto a polymer matrix. The methodology presented in this study should inspire the development of multifunctional intelligent materials for applications in related fields.