title: Impact of Viscous Droplets on Superamphiphobic Surfaces.
abstract: The impact of a liquid droplet on a solid surface is one of the most common phenomena in nature and frequently encountered in numerous technological processes. Despite the significant progress on understanding the droplet impact phenomenon over the past century, the impact dynamics, especially the coupling effects between the properties of a liquid and surface wettability on the impact process, is still poorly understood. In this work, we experimentally investigated the impact of viscous droplets on superamphiphobic surfaces, with the viscosity of liquids ranging from 0.89 to 150 mPa s. We showed that an increase in liquid viscosity will slow down the impact process and cause bouncing droplets to rebound lower and fewer times. The critical impact velocity, above which droplets can rebound from the superamphiphobic surface, was found to linearly increase with the liquid viscosity. We also showed that the maximum spreading factor increases with Weber number or Reynolds number but decreases with the liquid viscosity. Scaling analyses based on energy conservation were carried out to explain these findings, and they were found to be in good agreement with our experimental results.
authors.affiliation: State Key Laboratory of Traction Power, Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province, School of Mechanics and Engineering, Southwest Jiaotong University , Chengdu 610031, China.
authors.forename: Binyu
authors.initials: B
authors.lastname: Zhao
authors.affiliation: Department of Mechanical Engineering, Dongguan University of Technology , Dongguan 523808, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Wang
authors.affiliation: Wood Technology and Wood Chemistry, Georg-August-Universität Göttingen , Büsgenweg 4, Göttingen D-37077, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Traction Power, Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province, School of Mechanics and Engineering, Southwest Jiaotong University , Chengdu 610031, China.
authors.forename: Longquan
authors.identifier: 0000-0002-6785-5914
authors.initials: L
authors.lastname: Chen
authors.affiliation: Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China , Chengdu 610054, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Deng