Realizing of Anisotropic Wetting and Superhydrophobicity on Stainless Steel Surface by Combining Picosecond Laser Ablation and Electrodeposition

Abstract

Superhydrophobic surface with anisotropic wetting and no low‐surface‐energy modification is investigated in which laser ablation, ultrasonic cleaning with degreasing solution, and electrodeposition are used sequentially. The macrogrooves are prepared by laser, and the micro–nanoscale structures on macrogrooves are prepared by electrodeposition, which is important to study the effect of hierarchical structures on anisotropic wetting. Herein, the surface morphology and surface crystal structure are discussed with respect to the laser‐ablated surface and the subsequent degreasing solution super‐cleaning/electrodeposited surfaces. At the same time, stainless steel surfaces with grooves of different periodic intervals (30–150 μm) and depths (10–40 μm) are systematically fabricated by laser only. When the periodic interval is smaller (<=50 μm), the static anisotropy is not obvious (5°–7°). However, the smaller the groove periodic interval and the greater the depth (<=30 μm), the more obvious the sliding anisotropy. Finally, dense and uniform micro–nanostructures on laser‐ablated grooves are prepared by electrodeposition. The micro–nanohierarchical structures prepared by electrodeposition not only can make the droplets have superhydrophobic properties but also enhance the water drop's anisotropic sliding ability.