Microcapsule-Containing Self-Reporting Materials Based on Donor–acceptor Stenhouse Adducts

The microcapsule-containing self-reporting system has attracted attention for its excellent characteristics in visualizing microdamage. In this study, we developed self-reporting materials based on the formation of donor-acceptor Stenhouse adducts (DASA) from microcapsules containing Meldrum's acid furfural conjugate (MAFC). Under mechanical force, MAFC is released from broken microcapsules and forms highly colored DASA with secondary amines in the matrix to indicate the small cracks or deformations. Utilizing the photosensitive properties of DASA, highlighted regions fade under visible light, enabling indicator turn-off. The experimental results indicate that this convenient strategy can sensitively detect mechanical damage and optically control the indicator turn-off. These characteristics provide a means of distinguishing between different batches of damage and reusing self-reporting materials. Furthermore, this strategy exhibits compatibility with multiple types of matrix materials and can be extended to more complex systems by introducing a revealing agent.