Rewritable superhydrophobic coatings fabricated using water-soluble polyvinyl alcohol

Superhydrophobic surface has potential applications in various fields due to its excellent water repellency. In particular, fluorine-free superhydrophobic film has attracted extensive attentions. In this study, an eco-friendly and rewritable superhydrophobic coating is successfully prepared by a simple spray-coating method. Hydrophilic silica nanoparticles are immobilized on a substrate by water-soluble polyvinyl alcohol (PVA), and then the surface is further modified by polydimethylsiloxane (PDMS) to obtain a superhydrophobic coating. The prepared coating has a water contact angle of 160 o , and exhibits good stability. Most importantly, when the superhydrophobic coating is no longer needed, it can be removed and the substrate can be reused. The eco-friendly and rewritable superhydrophobic coating should have promising potentials in daily life.