疏水表面上固着双液滴相互作用的实验研究

Experimental Study on the Interaction of Sessile Double Droplets on Hydrophobic Surface

摘要: 本文通过实验观察成对液滴在疏水表面上蒸发过程，研究了成对液滴对于液滴蒸发的影响。将一对同样液滴放置在聚二甲基硅氧烷(PDMS)基板上，分析液滴之间的间距对双液滴蒸发造成的影响。实验结果表明，两个液滴之间的距离越小，对蒸发的抑制越强烈，单侧液滴呈现非对称状态，其靠近另一个液滴的一侧受到蒸发抑制明显，并且随着蒸发的进行与分离距离的增加，液滴之间的抑制作用逐渐降低。进一步探究了不同表面上液滴蒸发时间的规律，定义了蒸发速率校正因子K来确定双液滴蒸发的速率及特性。随后还讨论了不同表面上成对液滴蒸发速率校正因子的变化。本文的重点是在临界分离尺度下K (接近单液滴极限)的渐近行为。

Abstract: The evaporation process of sessile double droplets on hydrophobic surface was observed experimentally, and the effect of sessile double droplets on droplet evaporation was studied. Sessile double droplets are placed on the PDMS substrate. By changing the distance between the two droplets, the influence of the distance between the droplets on the evaporation of the two droplets is analyzed. The experimental results show that the smaller the distance between two droplets, the stronger the inhibition of evaporation. One side of the droplet presents an asymmetric state, and the side close to the other droplet is significantly inhibited by evaporation, and the inhibition between droplets decreases gradually with the progress of evaporation. Then, the experiment further explored the law of droplet evaporation time on different surfaces, and defined the evaporation rate correction factor K to determine the rate and characteristics of double droplet evaporation. The variation of double droplet evaporation rate correction factor on different surfaces is also discussed subsequently. The highlight of this paper is the asymptotic behavior of K (close to the single droplet limit) at the critical separation scale.