The impact of liquid drops on solid surfaces is a classical and beautiful phenomenon, which is familiar in day-to-day life, but also of great importance to many industrial processes. Although complete rebound of droplets is widely observed on superhydrophobic solid surfaces (Lotus leaves effect), the bouncing of droplets on liquid is usually vulnerable due to the easy collapse of air pocket entrapped between the impinging droplet and slippery and soft liquid interfaces (pitcher plant effect). Reported in Nature Communications, Chonglei Hao et al. discovered a robust superhydrophobic-like bouncing regime on thin liquid films, characterized by the contact time, the spreading dynamics, and the restitution coefficient independent of the underlying liquid substrate . Through experimental observation and theoretical analysis, we demonstrate that the emergence of such substrate-independent (superhydrophobic-like) bouncing necessitates an intricate interplay between the Weber number and the substrate features including the thickness and viscosity of the liquid film. The combination of robust superhydrophobic-like bouncing with the inherent advantages of slippery, mobile liquid interfaces will extend the applications of liquid film in many processes.
Chonglei Hao, Jing Li, Yuan Liu, Xiaofeng Zhou, Yahua Liu, Rong Liu, Lufeng Che, Wenzhong Zhou, Dong Sun, Lawrence Li, Lei Xu, Zuankai Wang. Superhydrophobic-like tunable droplet bouncing on slippery liquid interfaces. Nature Communications, 6, 7986 (2015).
Last modified on 3 July, 2018