Xia Zhenyan, Xiao Yuhe, Yang Zhen, Li Linan, Wang Shibin, Liu Xianping, Tian Yanling
School of Mechanical Engineering, Tianjin University, Tianjin 300350, China.
Key Laboratory of Mechanism Theory and Equipment Design, Ministry of Education, Tianjin University, Tianjin 300350, China.
Materials (Basel). 2019 Mar 6;12(5):765. doi: 10.3390/ma12050765.
A super-hydrophobic aluminum alloy surface with decorated pillar arrays was obtained by hybrid laser ablation and further silanization process. The as-prepared surface showed a high apparent contact angle of 158.2 ± 2.0° and low sliding angle of 3 ± 1°. Surface morphologies and surface chemistry were explored to obtain insights into the generation process of super-hydrophobicity. The main objective of this current work is to investigate the maximum spreading factor of water droplets impacting on the pillar-patterned super-hydrophobic surface based on the energy conservation concept. Although many previous studies have investigated the droplet impacting behavior on flat solid surfaces, the empirical models were proposed based on a few parameters including the Reynolds number (), Weber number (), as well as the Ohnesorge number (). This resulted in limitations for the super-hydrophobic surfaces due to the ignorance of the geometrical parameters of the pillars and viscous energy dissipation for liquid flow within the pillar arrays. In this paper, the maximum spreading factor was deduced from the perspective of energy balance, and the predicted results were in good agreement with our experimental results with a mean error of 4.99% and standard deviation of 0.10.
通过混合激光烧蚀和进一步的硅烷化工艺，获得了具有装饰性柱状阵列的超疏水铝合金表面。所制备的表面表现出158.2±2.0°的高表观接触角和3±1°的低滑动角。通过研究表面形貌和表面化学，深入了解超疏水性的产生过程。本工作的主要目的是基于能量守恒概念，研究水滴撞击柱状图案超疏水表面时的最大铺展因子。尽管之前有许多研究探讨了液滴在平坦固体表面上的撞击行为，但所提出的经验模型是基于包括雷诺数（）、韦伯数（）以及奥内佐格数（）在内的几个参数。由于忽略了柱状结构的几何参数以及柱状阵列内液体流动的粘性能量耗散，这导致这些模型在超疏水表面上存在局限性。在本文中，从能量平衡的角度推导出最大铺展因子，预测结果与我们的实验结果吻合良好，平均误差为4.99%，标准差为0.10。
