Liu Hanyi, Zhang Jun, Luo Jia, Wen Dongsheng
School of Aeronautic Science and Engineering, Beihang University, Beijing 100191, China.
TUM School of Engineering and Design, Technical University of Munich, 80333 Munich, Germany.
Phys Rev E. 2023 Jun;107(6-2):065101. doi: 10.1103/PhysRevE.107.065101.
Molecular dynamics simulations have been performed to study the dynamics of nanodroplets impacting on a flat superhydrophobic surface and surfaces covered with nanocone structures. We present a panorama of nanodroplet behaviors for a wide range of impact velocities and different cone geometrics, and develop a model to predict whether a nanodroplet impacting onto cone-textured surfaces will touch the underlying substrate during impact. The advantages and disadvantages of applying nanocone structures to the solid surface are revealed by the investigations into restitution coefficient and contact time. The effects of nanocone structures on droplet bouncing dynamics are probed using momentum analysis rather than conventional energy analysis. We further demonstrate that a single Weber number is inadequate for unifying the dynamics of macroscale and nanoscale droplets on cone-textured surfaces, and propose a combined dimensionless number to address it. The extensive findings of this study carry noteworthy implications for engineering applications, such as nanoprinting and nanomedicine on functional patterned surfaces, providing fundamental support for these technologies.
已进行分子动力学模拟，以研究纳米液滴撞击平坦超疏水表面及覆盖有纳米锥结构表面的动力学。我们展示了在广泛的撞击速度和不同锥几何形状下纳米液滴的行为全景，并开发了一个模型来预测撞击到带有锥纹理表面的纳米液滴在撞击过程中是否会接触下面的基底。通过对恢复系数和接触时间的研究，揭示了在固体表面应用纳米锥结构的优缺点。使用动量分析而非传统能量分析来探究纳米锥结构对液滴弹跳动力学的影响。我们进一步证明，单一的韦伯数不足以统一宏观和纳米尺度液滴在带有锥纹理表面上的动力学，并提出一个组合无量纲数来解决这一问题。本研究的广泛发现对工程应用具有重要意义，如在功能图案化表面上的纳米打印和纳米医学，为这些技术提供了基础支持。
