One-step fabrication of composites with superhydrophobic surfaces using spin-coating with polydimethylsiloxane/silica/solvent suspension

Abstract

Superhydrophobic surfaces can be obtained by fabricating hierarchical rough structures with low surface energies. In this study, composites with such superhydrophobic surfaces were fabricated by spin-coating a suspension composed of polydimethylsiloxane, ethanol, hexane, and silica powder. The composite exhibits a three-layered hierarchical structure comprising protrusions and pores resulting from liquid–liquid phase separation and silica aggregation. The fabricated three-layered hierarchical-structured composite films demonstrate water contact angles greater than 155° and sliding angles less than 10°. The results indicate that the proposed process is simple and useful in fabricating superhydrophobic surfaces.

Keywords:

• Polydimethylsiloxane
• spin-coating
• superhydrophobic surface
• hierarchical structure
• liquid–liquid phase separation

Acknowledgments

This work was partly supported by the Foundation of Public Interest of Tatematsu (2019).