Adjustable oil adhesion on superamphiphobic copper surfaces for controlled oil droplet transport

Abstract

The desirability of superamphiphobic surfaces, which possess both superhydrophobic and superoleophobic properties, for practical applications stems from their enhanced adaptability in oil-contaminated environments when compared to superhydrophobic surfaces. However, achieving superamphiphobic surfaces with adjustable oil adhesion through a simple, cost-effective, and reproducible fabrication process has proven challenging for researchers. This study presents an approach that combines laser etching with a chemical method to obtain superamphiphobic copper surfaces which demonstrated UV and corrosion resistance, as well as adjustable oil adhesion. The modified copper surface shows superamphiphobic properties, indicated by contact angles greater than 150° for water, colza oil, n-hexadecane, and crude oil. Significantly, the presence of concave-down micro/nano reentrant structures is found to be crucial in generating superamphiphobic properties. Additionally, the surface exhibits outstanding resistance to strong acids, strong alkalis, and saturated sodium chloride solutions. Even following a 48-hour exposure to UV irradiation, the contact angles for water and oil remain above 150°, demonstrating sustained UV resistance of the surface. Additionally, when in contact with water and crude oil, the surface exhibits outstanding anti-fouling and self-cleaning capabilities. Notably, the dimensions of the laser-etched grooves on the modified copper surface are adjusted, enabling customizable oil adhesion and controlled oil droplet transportation.