A superhydrophobic aerogel with robust self-healability

Self-healing is an effective strategy to improve the durability of a superhydrophobic surface, but a challenge remains in repairing its multi-scale structures and wettability simultaneously after damage. Here we report a self-healable superhydrophobic aerogel that spontaneously restores its superhydrophobicity, microstructure and macroscopic configuration simultaneously after physical or chemical damage. The superhydrophobic aerogel is fabricated by decorating an alginate-based aerogel with silver nanoparticles and octadecylamine (ODA). Once the aerogel is scratched or cut, it repairs both hierarchical structures and configuration integrity autonomously via wetting/heating processes, resulting in the recovery of superhydrophobicity and mechanical properties. Even after being etched with O2 plasma, it regains its superhydrophobic properties through a simple heat treatment. The robust healability is attributed to the dynamic catechol–Fe coordination as well as thermally induced rearrangement of ODA molecules. This concept of robust healability offers a new insight into the design of robust superhydrophobic surfaces aiming at various technological applications.