Universal spreading of water drops on complex surfaces.
Universal spreading of water drops on complex surfaces.
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DOI：
10.1039/c3sm52464g
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发表时间：
2014-03
期刊：
影响因子：
3.4
通讯作者：
Bram Stapelbroek;H. Jansen;Ernst S. Kooij;J. Snoeijer;A. Eddi
中科院分区：
文献类型：
--
作者：
Bram Stapelbroek;H. Jansen;Ernst S. Kooij;J. Snoeijer;A. Eddi
一滴水轻轻落在固体表面后，扩散得很快。在这里，我们通过实验研究了不同类型的表面复杂性如何影响这些早期阶段的扩散。我们特别考虑了微纹理衬底、化学条纹衬底和软衬底。对于所有这些复杂的衬底，发现总是存在一个惯性区，其中润湿区域的半径r随r ~ t（1/2）增长。对于完全润湿的基材，这种状态在时间上延长了几十年，而对于部分润湿的基材，我们观察到与纯幂律的偏差。我们的实验表明，即使从1/2幂定律到最终平衡半径的交叉也显示出普遍的动力学。这种交叉仅受最终接触角的控制，而与基板的细节无关。
A drop of water spreads very rapidly just after it is gently deposited on a solid surface. Here we experimentally investigate how these early stages of spreading are influenced by different types of surface complexity. In particular, we consider micro-textured substrates, chemically striped substrates and soft substrates. For all these complex substrates, it is found that there always exists an inertial regime where the radius r of the wetted area grows as r ∼ t(1/2). For perfectly wetting substrates, this regime extends over several decades in time, whereas we observe a deviation from a pure power-law for partially wetting substrates. Our experiments reveal that even the cross-over from the 1/2 power law to the final equilibrium radius displays a universal dynamics. This cross-over is governed only by the final contact angle, regardless of the details of the substrate.