Xiao Ke, Zhao Yanping, Ouyang Gang, Li Xinlei
MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, 510631, China.
Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Synergetic Innovation Center for Quantum Effects and Applications (SICQEA), Hunan Normal University, Changsha, 410081, China.
Nanoscale Res Lett. 2017 Dec;12(1):309. doi: 10.1186/s11671-017-2086-9. Epub 2017 Apr 26.
An analytic thermodynamic model has been established to quantitatively investigate the wetting states of droplets on nanopatterned surfaces. Based on the calculations for the free energies of droplets with the Wenzel state and the Cassie-Baxter state, it is found that the size and shape of nanostructured surfaces play crucial roles in wetting states. In detail, for nanohole-patterned surfaces, the deep and thin nanoholes lead to the Cassie-Baxter state, and contrarily, the shallow and thick nanoholes result in the Wenzel state. However, the droplets have the Wenzel state on the patterned surfaces with small height and radii nanopillars and have the Cassie-Baxter state when the height and radii of nanopillars are large. Furthermore, the intuitive phase diagrams of the wetting states of the droplet in the space of surface geometrical parameters are obtained. The theoretical results are in good agreement with the experimental observations and reveal physical mechanisms involved in the effects of nanopatterned surfaces on wetting states, which implies that these studies may provide useful guidance to the conscious design of patterned surfaces to control the wetting states of droplets.
已建立一个解析热力学模型，以定量研究纳米图案化表面上液滴的润湿状态。基于对处于文策尔状态和卡西-巴克斯特状态的液滴自由能的计算，发现纳米结构表面的尺寸和形状在润湿状态中起着关键作用。具体而言，对于纳米孔图案化表面，深而窄的纳米孔会导致卡西-巴克斯特状态，相反，浅而厚的纳米孔会导致文策尔状态。然而，液滴在具有小高度和半径的纳米柱的图案化表面上处于文策尔状态，而当纳米柱的高度和半径较大时则处于卡西-巴克斯特状态。此外，还获得了液滴在表面几何参数空间中润湿状态的直观相图。理论结果与实验观察结果吻合良好，揭示了纳米图案化表面对润湿状态影响所涉及的物理机制，这意味着这些研究可能为有意识地设计图案化表面以控制液滴的润湿状态提供有用的指导。
