Xu Jinkai, Hou Yonggang, Lian Zhongxu, Yu Zhanjiang, Wang Zuobin, Yu Huadong
Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing, Changchun University of Science and Technology, Changchun 130022, China.
International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun 130022, China.
Nanomaterials (Basel). 2020 Oct 27;10(11):2140. doi: 10.3390/nano10112140.
Many biological surfaces with the multi-scale microstructure show obvious anisotropic wetting characteristics, which have many potential applications in microfluidic systems, biomedicine, and biological excitation systems. However, it is still a challenge to accurately prepare a metal microstructured surface with multidirectional anisotropy using a simple but effective method. In this paper, inspired by the microstructures of rice leaves and butterfly wings, wire electrical discharge machining was used to build dual-level (submillimeter/micrometer) periodic groove structures on the surface of titanium alloy, and then a nanometer structure was obtained after alkali-hydrothermal reaction, forming a three-level (submillimeter/micrometer/nanometer) structure. The surface shows the obvious difference of bidirectional superhydrophobic and tridirectional anisotropic sliding after modification, and the special wettability is easily adjusted by changing the spacing and angle of the inclined groove. In addition, the results indicate that the ability of water droplets to spread along parallel and perpendicular directions on the submillimeter groove structure and the different resistances generated by the inclined groove surface are the main reasons for the multi-anisotropic wettability. The research gives insights into the potential applications of metal materials with multidirectional anisotropic wetting properties.
许多具有多尺度微观结构的生物表面呈现出明显的各向异性润湿特性，这在微流体系统、生物医学和生物激发系统中有许多潜在应用。然而，采用简单而有效的方法精确制备具有多向各向异性的金属微结构表面仍然是一项挑战。本文受水稻叶片和蝴蝶翅膀微观结构的启发，利用电火花线切割加工在钛合金表面构建双级（亚毫米/微米）周期性沟槽结构，然后经过碱-水热反应获得纳米结构，形成三级（亚毫米/微米/纳米）结构。改性后的表面呈现出双向超疏水和三向各向异性滑动的明显差异，通过改变倾斜沟槽的间距和角度可轻松调节特殊润湿性。此外，结果表明水滴在亚毫米沟槽结构上沿平行和垂直方向的铺展能力以及倾斜沟槽表面产生的不同阻力是多向各向异性润湿性的主要原因。该研究为具有多向各向异性润湿特性的金属材料的潜在应用提供了见解。
