A robust superhydrophobic coating fabricated by combination of laser texturing and electrostatic spraying for anti-soil adhesion

Superhydrophobic coatings have gained much attention in anti-ice adhesion applications due to their unique wettability. However, poor robustness greatly limits their application in anti-soil adhesion. In this paper, the PFA@SiO₂ superhydrophobic coating was electrostatically sprayed on the Mn13 steel with armadillo armor-like textures. The results show that the PFA@SiO₂ coating presents a micro-nano network structure with self-similar characteristics due to the influence of nano SiO₂ on the PFA melt fluidity, with a maximum contact angle of 156° and a minimum rolling angle of 2.3°. Notably, the texture-protected PFA@SiO₂ coating could still maintain its superhydrophobicity even after being scratched by sandpapered for 30 m at pressures up to 5.6 kPa. Moreover, the texture-protected PFA@SiO₂ coating has a low friction coefficient ∼ 0.3 which is 40 % less than that of the pure laser-textured steel. Compared with the untreated steel, the adhesion reduction of texture-protected PFA@SiO₂ coating to clay reached up to ∼ 89 % in normal and ∼ 91 % in tangential. In general, this robust superhydrophobic coating boasts a wide range of potential applications in agricultural machinery.