Effect of sessile drop volume on the wetting anisotropy observed on grooved surfaces.
Effect of sessile drop volume on the wetting anisotropy observed on grooved surfaces.
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DOI：
10.1021/la803942h
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发表时间：
2009-02
期刊：
影响因子：
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通讯作者：
Jing Yang;F. Rose;N. Gadegaard;M. Alexander
中科院分区：
文献类型：
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作者：
Jing Yang;F. Rose;N. Gadegaard;M. Alexander
本研究报告了使用 400 pL 至 4.5 µL 的液滴体积在具有不同宽度的凹槽的表面上测量的水接触角 (WCA) 的实验测量结果。这些测量是在使用地形压花聚（甲基丙烯酸甲酯）（PMMA）的保形等离子体聚合物涂层形成的相对疏水和亲水的表面化学上进行的。发现对于亲水和疏水表面上的较大液滴，凹槽表面的各向异性润湿更加明显。在一定的滴底直径与槽宽比之上，地形对测量的 WCA 没有影响；发现该比率取决于水滴体积。发现使用亚微升水滴从垂直于凹槽的方向测量的 WCA 可以很好地指示具有同等润湿性的平坦表面上的 WCA。据我们所知，这是首次使用皮升水滴研究各向异性润湿现象。
This study reports experimental measurements of the water contact angle (WCA) measured on surfaces with grooves of different widths using drop volumes ranging from 400 pL to 4.5 microL. These measurements were carried out on both relatively hydrophobic and hydrophilic surface chemistry formed using a conformal plasma polymer coating of topographically embossed poly(methyl methacrylate) (PMMA). Anisotropic wetting of the grooved surfaces was found to be more marked for larger drops on both the hydrophilic and hydrophobic surfaces. Above a certain drop base diameter to groove width ratio, topography had no effect on the measured WCA; this ratio was found to be dependent on the water drop volume. The WCA measured from the direction perpendicular to the grooves using submicroliter water drops is found to be a good indicator of the WCA on the flat surface with equivalent wettabilities. To the best of our knowledge, this is the first study on the phenomenon of anisotropic wetting using picoliter water drops.