Preparation and Wetting Mechanism of Laser-Etched Composite Self-Assembled 1H,1H,2H,2H-Perfluorodecyltriethoxysilane Superhydrophobic Surface Coating

Herein, a grid-like microstructure is prepared on the surface of 3Cr13 stainless steel through nanosecond laser etching, and the self-assembled 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDS) coating is further composited to prepare a superhydrophobic surface with a contact angle of 164° and a rolling angle of 3°. The effect of laser etching cycles on the surface microstructure and surface wettability before and after the self-assembly is studied. With an increase in the etching cycles, a stable grid-like microstructure is gradually formed on the surface, and subsequently, a composite structure of grooves and pits is formed. After the self-assembly of the PFDS coating, two superhydrophobic surfaces with different wetting properties are obtained. Furthermore, as the etching cycles increase, the surface changes from a superhydrophobic and high-adhesion state to a superhydrophobic and low-adhesion state. The decrease in surface energy is mainly attributed to the C−F group in the PFDS molecule. The experimental results show that PFDS molecules are deposited easily in case of the convex surface, thereby facilitating the formation of superhydrophobic low-adhesion surfaces. Finally, the superhydrophobic surface is still maintained after cumulative ultrasonic cleaning in deionized water for 75 min, showing good reusability and stability.