Near infrared light responsive self-healing superhydrophobic coating based on solid wastes.

Solid wastes, such as polystyrene foam waste and silica gel waste which are ubiquitous products have caused serious environmental issues, such as "white pollution", threatening the health of humans and animals. As such, the need to recycle and re-use of solid wastes has attracted increasing attention in the last few years. In this work, a self-healing superhydrophobic coating is successfully fabricated by blending polystyrene foam waste with fluorinated silica gel waste (F-silica gel waste), octadecyltrimethoxysilane (OTMS) modified silica particles (OTMS-silica particles), and near-infrared (NIR) light responsive microcapsules. The F-silica gel waste and OTMS-silica nanoparticles act as hydrophobic fillers meanwhile the polystyrene foam waste acts as a coating binder. The NIR-responsive microcapsules are obtained by the electrostatic adsorption of carbon nanoparticles onto the surface of microcapsules loaded with 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane. The superhydrophobic property of the coating can be healed after 10 min of NIR irradiation. Additionally, the as-prepared coating can be coated on several different substrates, similar to commercial coatings, and it is seen that its excellent superhydrophobic property is durable and is maintained even when the coating is subjected to a sand-drop test. The self-healing mechanism of the superhydrophobic coatings is also investigated.