Simultaneous realization of antifouling, self-healing, and strong substrate adhesion via a bioinspired self-stratification strategy

Antifouling ability and substrate adhesion are typical trade-offs seen for a silicone coating. Furthermore, the self-healable inability limits their duration. This study reports a bioinspired self-stratifying coating composed of a polyurethane with dopamine and silane pedant groups and a bi-silanol-terminated poly(dimethylsiloxane) with fluorocarbon and poly(ethylene glycol) segments as a reactive amphiphilic polymer (RAP). During coating formation, the RAP with low surface energy can be enriched on the surface due to the self-stratifying effects, whereas the bioinspired dopamine and silane groups provide the coating with strong substrate adhesion. Besides, the multiple hydrogen bonds formed between the urethane linkages and the dopamine groups allow the coating to heal. Our study indicates such a polyurethane-based coating has excellent antifouling ability against proteins, bacteria, and diatoms, good self-healing performance at room temperature in air and water, as well as high adhesion strength on various substrates such as ceramic, steel, glass, and wood. This study provides a promising and universal strategy for the simultaneous realization of antifouling, self-healing, and strong substrate adhesion. The coatings could meet the needs of applications in marine antifouling, biomedical instruments, and other fields.