Glow Stick‐Inspired Multilayered Composites with Damage Self‐Reporting and Self‐Healing Properties for Aquatic Environments

Materials are inevitable to suffer from mechanical damage such as scratches or cuts when they are exposed to the marine environment. Herein, a hierarchical composite material is fabricated, which demonstrates the self‐reporting and self‐healing behaviors in aquatic environments including deionized water, seawater, acidic, and basic aqueous solutions. The composite material is constructed of a five‐layer structure and shows excellent responsiveness to water molecules. After the material is damaged underwater, the chemiluminescence reaction comes into being quickly and the luminescence signal can last for over 3 h, allowing for timely and rapid reporting of damage. Furthermore, materials demonstrate high stretchability and self‐healing behavior, making them possible to serve as soft products used in underwater environments.