Liao Ying-Chih, Chiang Cheng-Kun, Lu Yen-Wen
Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan.
J Nanosci Nanotechnol. 2013 Apr;13(4):2729-34. doi: 10.1166/jnn.2013.7345.
Nanowire arrays with various agglomeration patterns were synthesized by adjusting the solvent evaporation rates. Nanowires with 200 nm diameter and 2-25 microm in length were fabricated from an anodic aluminum oxide (AAO) porous template. Various drying treatments were applied to develop nanostructured surfaces with topological differences. Due to surface tension forces, copper nanowires after thermal and evaporative drying treatments agglomerated into clusters, while supercritical drying technique provided excellent bundled-free and vertically-standing nanowire arrays. Although all dried surfaces exhibited hydrophobic nature, the contact angle hysteresis, or the difference between advancing and receding angles, was found to be larger on those surfaces with bundled nanowire clusters. To explain the difference, the wetted solid fraction on each surface was calculated using the Cassie-Baxter model to show that the hysteresis was contributed by liquid/solid contact area on the textured surfaces.
通过调节溶剂蒸发速率合成了具有各种团聚模式的纳米线阵列。由阳极氧化铝（AAO）多孔模板制备出直径为200nm、长度为2 - 25微米的纳米线。采用了各种干燥处理来开发具有拓扑差异的纳米结构表面。由于表面张力的作用，经过热干燥和蒸发干燥处理后的铜纳米线团聚成簇，而超临界干燥技术提供了优异的无束状且垂直排列的纳米线阵列。尽管所有干燥表面都呈现出疏水性，但发现具有束状纳米线簇的表面上的接触角滞后现象，即前进角和后退角之间的差异更大。为了解释这种差异，使用卡西 - 巴克斯特模型计算了每个表面上的湿润固体分数，结果表明滞后现象是由纹理表面上的液 - 固接触面积造成的。
