Facile and Eco-Friendly Fabrication of Superhydrophilic and Superhydrophobic Sic Surfaces by Nanosecond Laser Treatment

Abstract

Superhydrophobic silicon carbide surfaces have been shown substantial attentions for their potential applications in aerospace, ship domain, military etc. fields. In this work, we use nanosecond laser and fluorine-free N-Octyltriethoxysilane (OcTES) were used to fabricate SiC surfaces, which could turn superhydrophilic to superhydrophobic. Superhydrophilic surfaces were made in a few minutes through laser treatment and the time required to convert it to superhydrophobic surfaces is only 1h. The apparent water contact angle (WCA) of superhydrophilic SiC could reach close to 0o. The number of hydrophilic polar bonds on SiC surfaces will increase and non-polar bonds of hydrophobicity will decrease due to the oxidation in the process of laser treatment. After OcTES treatment, the SiC surface was transformed from superhydrophilic to superhydrophobic (WCA of 153o). The results indicated that the surface roughness and the chemical compositions were critical for superhydrophobicity. It was found that Si-O-Si groups will be formed on SiC surfaces in the atmosphere environment, so the hydrophobicity of the material surface was enhanced. At the same time, superhydrophobic SiC surfaces also have excellent low-adhesion and anti-icing properties, presenting potential interest for wettability applications.

Keywords: nanosecond laser, silicon carbide ceramics, superhydrophilic/hydrophobic, low-adhesion, anti-icing