Silica Janus Particle-Based Coating Applicable to Multiple Substrates Shows Durable Superhydrophobicity, Wear Resistance, and Corrosion Inhibition.

The present work reports the fabrication of a durable superhydrophobic coating based on silica Janus particles. One side of the silica particles was modified by (3-aminopropyl)triethoxysilane to have a reactive alkylamine group, and the other side was treated with octadecyltrimethoxysilane to be hydrophobic. These Janus particles were held together by binder molecules that reacted with the amines attached to the Janus particles and adhered to different substrates, forming superhydrophobic coatings. The water contact angles of the coatings were higher than 158°, whereas their sliding angles were as low as 2°. Their hydrophobicity was preserved even after 200 cycles of intensive abrasion or after 60 days of immersion in 3.5% NaCl solution, evidencing their durable resistance to abrasion and corrosion. The most remarkable property of the presented Janus silica particle-based coating is that it can strongly adhere to multiple substrates such as active metal aluminum, flat substrate glass, biological material wood, and organic polymer with low surface energy polyperfluoroethylene. Moreover, the hydrophobicity, antiwear resistance, and corrosion inhibition ability of the fabricated coating were independent of the substrates. This superiority enables this coating to cover many substrates with different surface properties to fulfill a variety of technical demands.