One-step fabrication of robust liquid-repellent mesh induced by femtosecond laser

Abstract

Super liquid-repellent surfaces are deemed as an ideal candidate for self-cleaning and liquid separation. However, these surfaces still confront challenges in the aspect of inadequate mechanical durability, environmentally harmful reagents and complex fabrication procedures. Herein, a one-step femtosecond laser ablation process on various porous mesh with PDMS-assisted coverage was conducted. Then, the uniform and hierarchical micro-groove structures were formed on the cylindrical wires during the successive laser pyrolysis, accompanying by the hydrophobic silica deposited inside the micro-groove structures. The whole processing has no chemical solvents and complicated modification, which is of great significance for time-saving and eco-friendly preparation of mesh with super-hydrophobicity. Significantly, the super-hydrophobic mesh can bear 2000 abrasion cycle tests, 400 ℃ heat treatment and violent outdoor robustness tests, verifying its strong mechanical durability and thermal stability. The mechanisms involved in liquid-repellence and abrasion-resistance have been elucidated systematically. Furthermore, self-cleaning and on-demand oil water separation could be accomplished via tailoring the wettability of the mesh according to the oxygen plasma treatment and re-heating. The unique advantages of the as-prepared porous mesh provide feasibilities for wettability-oriented application such as protective surface with self-cleaning ability, multitasking immiscible liquid separation.