A comparative study about superamphiphobicity and stability of superamphiphobic coatings based on Palygorskite

Abstract Naturally rich clay minerals are receiving increasing attention recently in preparation of super anti-wetting coatings, superhydrophobic and superamphiphobic ones. Clay minerals are a class of very promising natural building blocks for constructing microstructures of the coatings. Clay minerals such as Palygorskite (Pal), kaolinite, halloysite nanotubes and montmorillonite have been used. However, the comparative study about the effects of source of clay minerals on properties of the coatings remains a gap to be filled. Here, the first comparative study about superamphiphobicity and stability of superamphiphobic coatings based on Pal from different sources was reported. The superamphiphobic coatings were fabricated by hydrolytic condensation of silanes in the presence of Pal followed by spray-coating the as-prepared dispersions onto substrates. Five Pal samples from Anhui, Jiangsu and Gansu Provinces of China were chosen, and their effects on superamphiphobicity and stability of the coatings were studied using various analytical techniques including scanning electron microscopy and X-ray photoelectron spectroscopy. The superamphiphobicity and stability depend on micro/nanostructures of the coatings, originating from the microstructures of Pal. The Pal sample from Anhui is more suitable for preparing superamphiphobic coatings than the others because of the higher Mg content and the higher aspect ratio of the Pal nanorods. The finding will shed light on the progress of the clay-based super anti-wetting coatings.