Fabrication of superamphiphobic surfaces with controllable oil adhesion in air

Abstract

Researchers have been chasing controlling liquid adhesion for decades. Up to now, there are plenty of publications about controlling water adhesion in air and controlling oil adhesion underwater. However, the regulation of oil adhesive ability on superamphiphobic surfaces in air has been rarely addressed. In this article, we reported a method to fabricate superamphiphobic surface showing outstanding superhydrophobicity as well as tunable oil adhesion. Herein, a laser-chemical hybrid method was utilized to obtain superamphiphobic surfaces. We fabricated grid-like microstructures on copper substrate by nanosecond laser directly writing (LDW), and created nanorods on the surface by a facile alkali assistant oxidation (AAO) reaction, which was followed by a perfluoroalkylthiolate (PF-thiolate) reaction. By changing the grid spacing (GS) during LDW, the as-prepared superamphiphobic surface showed tunable oil adhesion, and oil (e.g., peanut oil and hexadecane) droplets could easily rolled-off from the surface (i.e., ultralow adhesion) or totally adhered to the surface (i.e., ultrahigh adhesion), upon which we realized oil droplets transportation. This work may provide a simple method of fabricating superamphiphobic surface and controlling oil adhesion in atmosphere, which can be potentially applied in numerous fields like microdroplet manipulation, microfluidic chips, microreactors and so on.