Anti-greasy and conductive superamphiphobic coating applied to the carbon brushes/conductive rings of hydro-generators

Abstract

A superamphiphobic coating is usually prepared via a reduction reaction and then deposited onto the surface of the substrate. This technology is difficult to control and achieve high bond strength, which easily leads to powder shedding. To overcome this issue, electroplating technology is usually preferred for preparing adhesion coatings. However, the coating prepared using this method is usually suitable only for hard steel substrates, and not for soft substrates such as carbon brushes. Herein, we demonstrate an air spray technology for preparing anti-greasy and conductive superamphiphobic graphite-1H,1H,2H,2H-perfluorooctyltrichlorosilane–SiO₂ (GPS) coatings suitable for both soft substrates (carbon brushes) and hard substrates (collector rings). The sheet resistance of the coating with 10% graphite content is 4.8 × 10⁻³ Ω □⁻¹ for a 10 μm thin coating, corresponding to a resistivity of 4.8 μΩ cm. More importantly, the prepared coating has excellent liquid repellency, such as water, rapeseed oil and n-hexane. In addition, the coating has excellent anti-greasy and mechanical properties, which provide a brand-new solution for the greasy pollution in the engineering field. These advantages will enhance the application of superamphiphobic GPS coating in the fields of hydropower, wind power and transportation, and so on.