Repeated self-healing of composite coatings with core-shell fibres

Core-shell fibres encapsulating epoxy monomer and curing agent were fabricated using coaxial electrospinning. Composite coatings with repeated self-healing properties were prepared by infiltrating waterborne polyurethane matrix into the core-shell fibre preform. Once cracks appeared at the same spot repeatedly, the electrospun fibre can supply healing agents to the cracks continuously, until the encapsulated healing agents were consumed. According to the morphology observation and Tafel tests, the composite coatings with a fibre content of 40.4 wt % can heal the cracks repeatedly and spontaneously for three times. After the three-times repeated healing, the self-healing efficiency remained at 99.34% according to the Tafel tests.