Zhao Zhipeng, Li Huizeng, Li An, Fang Wei, Cai Zheren, Li Mingzhu, Feng Xiqiao, Song Yanlin
Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences (ICCAS)/Beijing Engineering Research Center of Nanomaterials for Green Printing Technology, Beijing National Laboratory for Molecular Sciences (BNLMS), Beijing, 100190, People's Republic of China.
University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
Nat Commun. 2021 Nov 25;12(1):6899. doi: 10.1038/s41467-021-27237-0.
Droplet impact on solid surfaces is essential for natural and industrial processes. Particularly, controlling the instability after droplet impact, and avoiding the satellite drops generation, have aroused great interest for its significance in inkjet printing, pesticide spraying, and hydroelectric power collection. Herein, we found that breaking the symmetry of the droplet impact dynamics using patterned-wettability surfaces can suppress the Plateau-Rayleigh instability during the droplet rebounding and improve the energy collection efficiency. Systematic experimental investigation, together with mechanical modeling and numerical simulation, revealed that the asymmetric wettability patterns can regulate the internal liquid flow and reduce the vertical velocity gradient inside the droplet, thus suppressing the instability during droplet rebounding and eliminating the satellite drops. Accordingly, the droplet energy utilization was promoted, as demonstrated by the improved hydroelectric power generation efficiency by 36.5%. These findings deepen the understanding of the wettability-induced asymmetrical droplet dynamics during the liquid-solid interactions, and facilitate related applications such as hydroelectric power generation and materials transportation.
液滴对固体表面的撞击对于自然和工业过程至关重要。特别是，控制液滴撞击后的不稳定性并避免产生卫星液滴，因其在喷墨打印、农药喷洒和水力发电收集方面的重要性而引起了极大的兴趣。在此，我们发现使用具有图案化润湿性的表面打破液滴撞击动力学的对称性，可以抑制液滴反弹过程中的 Plateau-Rayleigh 不稳定性，并提高能量收集效率。系统的实验研究，结合力学建模和数值模拟，表明不对称润湿性图案可以调节内部液体流动并降低液滴内部的垂直速度梯度，从而抑制液滴反弹过程中的不稳定性并消除卫星液滴。相应地，液滴能量利用率得到提高，水力发电效率提高 36.5% 就证明了这一点。这些发现加深了对液固相互作用过程中润湿性诱导的不对称液滴动力学的理解，并促进了水力发电和材料运输等相关应用。
