He Dongyun, Rui Zhiyuan, Lyu Xin, Sun Haobo, Fu Rong, Zhang Ling, Dong Yun
School of Mechanical and Electrical Engineering, Lanzhou University of Technology, Lanzhou 730050, People's Republic of China.
School of Mechatronics Engineering, Lanzhou Institute of Technology, Lanzhou 730050, People's Republic of China.
Langmuir. 2024 Sep 12. doi: 10.1021/acs.langmuir.4c01975.
Vibration affects the wetting behavior of droplets, and it is feasible to use vibration to modulate the adhesion characteristics of droplets. In this paper, the effect of vertical sinusoidal vibrations on the wettability of molten aluminum droplets on the substrate surfaces of smooth and with nanopillars is investigated. The increase in the frequency or amplitude of the vibration leads to a rise in the interfacial potential energy between the molten droplets and the substrate, which in turn leads to the occurrence of the Wenzel-Cassie transition. Once the vibration frequency reaches the threshold values, the molten droplets leave from the substrate, that is, dewetting occurs. The molten droplets in the Wenzel state undergo a Wenzel-Cassie transition before dewetting occurs. A phase diagram describing the frequency thresholds at which the molten aluminum droplets undergo dewetting and the Wenzel-Cassie transition at different amplitudes is plotted. For a specific amplitude, the frequency of vibration required for dewetting to occur in molten aluminum droplets in the Young state is lower than that in the Wenzel state. The needed vibrational frequency for dewetting or the Wenzel-Cassie transition decreases with increasing amplitude.
振动会影响液滴的润湿行为，利用振动来调节液滴的粘附特性是可行的。本文研究了垂直正弦振动对光滑和带有纳米柱的基底表面上熔融铝液滴润湿性的影响。振动频率或振幅的增加会导致熔融液滴与基底之间的界面势能升高，进而导致文泽尔 - 卡西转变的发生。一旦振动频率达到阈值，熔融液滴就会从基底上脱离，即发生去湿现象。处于文泽尔状态的熔融液滴在去湿发生之前会经历文泽尔 - 卡西转变。绘制了一个相图，描述了熔融铝液滴在不同振幅下发生去湿和文泽尔 - 卡西转变的频率阈值。对于特定的振幅，处于杨氏状态的熔融铝液滴发生去湿所需的振动频率低于处于文泽尔状态的情况。去湿或文泽尔 - 卡西转变所需的振动频率随振幅增加而降低。
