Highly compressible and stretchable superhydrophobic coating inspired by bio-adhesion of marine mussels - Journal of Materials Chemistry A (RSC Publishing)
Mechanical durability is an important issue for the fabrication and application of superhydrophobic coatings, but rare studies reported such a coating could withstand both large-strain compression and stretching. In this study, a highly compressible and stretchable superhydrophobic coating was constructed on the surface of commercial polyurethane (PU) sponges, inspired by the bio-adhesion of marine mussels. The coating consisted of sandwich-like multilayers constructed through layer-by-layer deposition of polydopamine (PDA) films and Ag nanoparticles. Under large strain conditions, the resulting coating could withstand 6000-cycle compressions, as well as 2000-cycle tensile measurements without losing superhydrophobicity, exhibiting outstanding mechanical robustness among the existing counterparts. The mechanism for the high compressibility and stretchability is believed to arise from the strong interactions between silver nanoparticles, PDA interlayers and sponge skeletons. Additionally, the coating also exhibited excellent anti-icing property at -15 oC. Because of simple synthesis process and almost nonselective adhesion of PDA, the results might provide a facile and versatile route to fabricate mechanically robust coatings on elastic substrates for various technological applications.
