Mechanically stable superhydrophobic coating of crosslinked polymer composite with self-healing ability

Sustainable superhydrophobicity is of significance for practical application of superhydrophobic coatings. We fabricated a mechanically stable superhydrophobic coating with self-healing performance by spray-coating a composite suspension of poly(vinyl butyral)-hexamethylene diisocyanate and octadecylamine (PVB-HDI/ODA) on various substrates. In the as-obtained composite, PVB-HDI formed 3D self-crosslinked polymer networks which not only impart the coating with high mechanical stability but also provide strong bonding force between the coating and the substrate, and ODA formed pedal-like structures which roughened the coating surface with low surface energy. Consequently, the coating possessed superhydrophobicity with a water contact angle up to 163.9° and a sliding angle lower to 1.0°. Notably, the as-obtained coating sustained its water repellency even after being exposed to various mechanical and chemical treatments. Moreover, the coating exhibited a self-healing ability in superhydrophobicity against O2 plasma etching. Such mechanical and chemical stabilities with self-healing ability are favourable to the superhydrophobic coating to prolong the lifespan for practical applications.