Tip Geometry Controls Adhesive States of Superhydrophobic Surfaces
Tip Geometry Controls Adhesive States of Superhydrophobic Surfaces
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DOI：
10.1021/la904510n
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发表时间：
2010-06-01
期刊：
影响因子：
3.9
通讯作者：
Jiang, Lei
中科院分区：
文献类型：
--
作者：
Cheng, Zhongjun;Gao, Jun;Jiang, Lei
受生物附着系统的启发，用一种简单、可重复的方法制备了端接在平面凹尖和纳米管中的定向聚苯乙烯(PS)纳米管。所有得到的表面都显示出接触角大于150度(超疏水)和高附着力的水。针尖几何形状对胶粘剂的粘接性能起着重要作用。具有凹尖的表面附着力最高，其次是具有平尖的表面，而排列的纳米管表面的附着力相对较低。除了PS表面与水之间的范德华作用力不同外，另一个重要因素，即不同密封空气体积所产生的不同负压，可能是导致它们不同粘附性的关键因素。这些发现为针尖几何形状对结构超疏水表面附着的影响提供了实验证据，有助于我们进一步了解生物附着系统和优化人工类似物的设计。
Inspired by biological attachment systems, aligned polystyrene (PS) nanopillars terminating in flat, concave tips and nanotubes were fabricated by a simple and reproducible method. All the obtained surfaces show both the contact angles larger than 150 degrees (superhydrophobicity) and high adhesion of water to it. The tip geometry plays an important role in determining the adhesive property. Surface with the concave tips has the highest adhesion, and then the surface with flat tips, whereas aligned nanotube surface has a relatively lower adhesion. Besides different van der Waals forces between the PS surfaces and water, another important factor, i.e., different negative pressures produced by the different volumes of sealed air, may be the crucial factor for their different adhesions. These findings provide the experimental evidence of the influence of the tip geometry on the adhesion of structured superhydrophobic surfaces, which is helpful for us to further understand the biological attachment systems and to optimum design of artificial analogues.