皮秒激光参数对仿生跨尺度乳突织构表面润湿性的影响

无修饰的金属疏水表面受到广泛关注,尤其是具有超高疏水性表面的制备方法逐渐被重视。通过皮秒激光烧蚀、电化学抛光和电化学沉积的顺序加工方法在铜表面制备一系列具有不同微观特征的乳突织构。系统研究激光功率、重复频率、扫描速度和扫描次数对乳突织构表面形貌及疏水性的影响,并分析表面润湿性的转化机理。研究结果表明,激光功率9 W、重复频率2 MHz、扫描速度200 mm/s、扫描次数20次时,跨尺度乳突织构表面静置30 d后可获得超高疏水性(接触角161°,滚动角1°)。储存30 d后,亲水性的Ni、CuO转化为疏水性的NiO、Ni(OH)_2、Cu_2O,以及含C有机物的吸附促成了乳突织构表面润湿性的转化。

Effects of Picosecond Laser Parameters on Surface Wettability of Cross-scale Bionic Mastoid-like Texture

Unmodified metal hydrophobic surfaces are extensively reported, and especially, the preparing methods of super- hydrophobic surfaces attract tremendous attention. Matoid-like texture surfaces with different microstructures are fabricated by the sequential methods, which contains laser ablation, electropolishing and electro-deposition. The effects of laser power, repetition frequency, scanning speed and scanning times on surface morphology and wettability of mastoid-like texture are systematically studied, and then, the transformation mechanism of surface wettability is analyzed. The ultra-high hydrophobicity of cross-scale mastoid-like texture surface can be reached after 30 days when laser power is 9 W, the repetition frequency is 2 MHz, the scanning speed is 200 mm/ s and the scanning is 20 times. The highest contact angle is 161° and the lowest sliding angle is 1°. After being stored for 30 days, the wettability conversion benefites from the transformation of hydrophilic Ni and CuO into hydrophobic NiO, Ni(OH)2 and Cu2O, and the adsorption of C-containing organics.