Universal spreading of water drops on complex surfaces

作者：Stapelbroek B B J^*; Jansen H P; Kooij E S; Snoeijer J H; Eddi A

来源：Soft Matter, 2014, 10(15): 2641-2648.

DOI：10.1039/c3sm52464g

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 similar to 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.

• 出版日期2014