Yu Fanfei, Lin Shiji, Yang Jinlong, Fan Yue, Wang Dehui, Chen Longquan, Deng Xu
Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China Chengdu 610054 P. R. China.
School of Physics University of Electronic Science and Technology of China Chengdu 610054 P. R. China.
Adv Sci (Weinh). 2020 Jan 10;7(4):1902687. doi: 10.1002/advs.201902687. eCollection 2020 Feb.
It is widely acknowledged that splash impact can be suppressed by increasing the viscosity of the impinging drop. In this work, however, by imposing a highly viscous drop to a low-viscosity drop, it is demonstrated that the splash of the low-viscosity part of this Janus drop on superamphiphobic surfaces can be significantly promoted. The underlying mechanism is that the viscous stress exerted by the low-viscosity component drives the viscous component moving in the opposite direction, enhancing the spreading of the low-viscosity side and thereby its rim instability. The threshold velocity, above which splashing occurs, can be tuned by varying the viscosity ratio of the Janus drop. Moreover, the impact of the Janus drop can be employed to verify the mechanism of splash.
人们普遍认为，通过增加撞击液滴的粘度可以抑制飞溅冲击。然而，在这项工作中，通过将高粘度液滴施加到低粘度液滴上，证明了这种Janus液滴的低粘度部分在超疏水表面上的飞溅可以得到显著促进。其潜在机制是，低粘度组分施加的粘性应力驱动粘性组分向相反方向移动，增强了低粘度侧的铺展，从而增强了其边缘不稳定性。发生飞溅的阈值速度可以通过改变Janus液滴的粘度比来调节。此外，Janus液滴的撞击可用于验证飞溅的机制。
