Fabrication of biomimetic superhydrophobic surface based on nanosecond laser-treated titanium alloy surface and organic polysilazane composite coating

Superhydrophobic surfaces have shown great potential applications in many fields and attracted tremendous attention and research efforts in recent years. In this study, the nanosecond laser technology was applied on the surface of titanium alloy and then functionalized the surface by the organic polysilazane (OPZ) coating to obtain a novel biomimetic superhydrophobic surface. The lotus-leaf-like micro-nanoscale hierarchical structure have been prepared on titanium alloy surface under the combined action of pulse laser's ablation, melting and bombardment by the nanosecond laser. By applying OPZ instead of the expensive fluorocarbon which is harmful to the environment to modify the substrate, we found that the as-synthesized surfaces exhibited outstanding water repellence (water contact angle (WCA) = 164.1 degrees) and non-stickiness behavior (sliding angle (SA) = 1.5 degrees), which indicates the low surface free energy of OPZ coating. Furthermore, the addition of ZnO nanoparticles into the OPZ coating significantly improves the corrosion resistance and antibacterial property of the super hydrophobic surface after laser treatment, achieving inhibition rate of 93.89% in fighting against E. coli. It is believed that the facile and low-cost method can expand the new application of superhydrophobic surface with low adhesive on titanium alloy in biomedical and anti-fouling fields.