Wetting stability of flexible superamphiphobic surfaces under stretching loading

Wetting stability is important for superamphiphobic surfaces used in oil–water environments. Maintaining the wetting stability of flexible superamphiphobic surfaces under stretching is challenging. Here, flexible surfaces with stable superamphiphobicity under stretching were fabricated by covering flexible polydimethylsiloxane substrates with superamphiphobic powders. Superamphiphobic powders composed of micro- and nanoparticles were prepared by a chemical substitution reaction and modification treatment. The fabricated flexible surfaces possessed contact angles for water, kerosene and peanut oil of 155, 152 and 153°, respectively, exhibiting superhydrophobicity and superoleophobicity. The self-cleaning properties of the fabricated flexible surface were studied by removing contaminants from the surfaces using water and oil droplets. Also, the wettability and morphology of the fabricated flexible surface under stretching were investigated. It was found that the fabricated flexible surface maintained stable superhydrophobicity and superoleophobicity when the stretching strain reached 60% due to the fact that it still kept micro–nano double-scale structures after being stretched. The fabricated flexible surface coated with superamphiphobic powders with wetting stability is expected to be used in the field of liquid repellency.