Efficient fabrication of ternary coupling biomimetic superhydrophobic surfaces with superior performance of anti-wetting and self-cleaning by a simple two-step method

Abstract

Efficiently obtaining ideal superhydrophobic metallic surfaces through traditional laser ablation is still a challenge. Meanwhile, revealing the mechanism of the transition from superhydrophilic to superhydrophobic of laser-ablated metallic surfaces is required. Inspired by the lotus leaf, we fabricated the arrays of micro-protrusions on aluminum substrates by nanosecond laser ablation. A layer of hydrophobic species was formed on the micro-protrusions after organic adsorption process, which promoted the surface to obtain superior superhydrophobic, anti-wetting and self-cleaning properties. The principle of the transition from superhydrophilic to superhydrophobic during heat treatment process was revealed, and how organic adsorption temperature and time affect water contact angle and slide angle was clarified. We found that nano-particles can drastically reduce the solid–liquid fraction of the surface after analysis. The parameters including laser scanning space, organic adsorption time and heat treatment temperature were optimized to realize high-efficient and energy-saving production. Furthermore, superior wetting resistance to various solutions and the self-cleaning property for solid powders were experimentally indicated. Superhydrophobic aluminum surfaces could be efficiently fabricated in several hours without any expensive equipment, complicated process, strict environment and environmentally harmful chemical reagent by the proposed two-step method.