Xie Fang-Fang, Lv Shu-Hang, Yang Yan-Ru, Wang Xiao-Dong
Research Center of Engineering Thermophysics, North China Electric Power University, Beijing 102206, China.
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China.
J Phys Chem Lett. 2020 Apr 16;11(8):2818-2823. doi: 10.1021/acs.jpclett.0c00788. Epub 2020 Mar 25.
We study the bouncing dynamics of nanodroplets on superhydrophobic surfaces. We show that there are three velocity regimes with different scaling laws of the contact time, τ. Although τ remains constant over a wide velocity range, as seen for macroscale bouncing, we demonstrate that viscosity plays an essential role in nanodroplet bouncing even for low-viscosity fluids. We propose a new scaling τ ∼ (/γ) = (/) to characterize the viscosity effect, which agrees well with the simulated results for water and argon nanodroplets with various radii and hydrophobicities. We also find pancake bouncing of nanodroplets, which is responsible for an abruptly reduced τ in a high-velocity regime.
我们研究了纳米液滴在超疏水表面上的弹跳动力学。我们表明，存在三种具有不同接触时间τ缩放定律的速度 regime。尽管τ在很宽的速度范围内保持恒定，如宏观尺度弹跳中所见，但我们证明，即使对于低粘度流体，粘度在纳米液滴弹跳中也起着至关重要的作用。我们提出了一种新的缩放关系τ ∼ (/γ) = (/)来表征粘度效应，这与不同半径和疏水性的水和氩纳米液滴的模拟结果非常吻合。我们还发现了纳米液滴的薄饼状弹跳，这导致了高速 regime 中τ的突然减小。
