Lasting and self-healing superhydrophobic surfaces by coating of polystyrene/SiO2 nanoparticles and polydimethylsiloxane

Abstract

Maintaining hierarchical roughness and a low surface energy property are keys to long lasting superhydrophobic surfaces. By spraying polystyrene/SiO₂ core/shell nanoparticles as a coating skeleton and polydimethylsiloxane as hydrophobic interconnection, lasting and self-healing superhydrophobic surfaces were fabricated. The coating exposed new roughening structures during the rubbing process, thus maintaining a suitable hierarchical roughness, favouring a superhydrophobic property of the surface. Also, the superhydrophobicity of a damaged surface from an air plasma treatment could be automatically restored in 12 h at room temperature or by heat curing and tetrahydrofuran treatment, which helped with the release of hydrophobic polystyrene. This strategy may find practical applications in all kinds of substrates because spray coating is a simple process, and the obtained surfaces possess lasting superhydrophobicity.