Yang Zhengyu, Barbhai Sainath, Ji Bingqiang, Feng Jie
Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Soft Matter. 2024 Jun 26;20(25):4868-4877. doi: 10.1039/d4sm00243a.
Jet drops resulting from bubble bursting at a liquid surface play a key role in various mass transfer processes across the interface, including sea spray aerosol generation and pathogen transmission. However, the impact of structurally compound interfaces, characterized by complex surface rheology introduced by surface-active contaminants, on the jet drop ejection still remains unclear. Here, we experimentally investigate the influence of surface viscoelasticity on the size and velocity of the top jet drops from surface bubble bursting, examining both pure protein and mixed protein-surfactant solutions. We document that for bubble bursting at a pure-protein-laden surface where surface elasticity dominates, the increase in , the interfacial elastocapillary number as the ratio between the effects of interfacial elasticity and capillarity, efficiently increases the radius and decreases the velocity of the top jet drop, ultimately inhibiting the jet drop ejection. On the other hand, considering the mixed protein-surfactant solution, we show that the top jet drop radius and velocity exhibit a different variation trend with , which is attributed to the additional dissipation on the capillary waves as well as the retardation and resistance on the converging flow for jet formation from surface viscoelasticity. Our work may advance the understanding of bubble bursting dynamics at contaminated liquid surfaces and shed light on the potential influence of surface viscoelasticity on the generation of bubble bursting aerosols.
液面上气泡破裂产生的喷射液滴在各种跨界面传质过程中起着关键作用，包括海喷雾气溶胶的产生和病原体传播。然而，由表面活性污染物引入的复杂表面流变学所表征的结构复合界面，对喷射液滴喷射的影响仍不清楚。在这里，我们通过实验研究了表面粘弹性对表面气泡破裂产生的顶部喷射液滴大小和速度的影响，研究了纯蛋白质溶液和蛋白质 - 表面活性剂混合溶液。我们记录到，对于在以表面弹性为主的纯蛋白质负载表面上的气泡破裂，作为界面弹性和毛细作用效应之比的界面弹性毛细管数的增加，有效地增加了顶部喷射液滴的半径并降低了其速度，最终抑制了喷射液滴的喷射。另一方面，对于蛋白质 - 表面活性剂混合溶液，我们表明顶部喷射液滴的半径和速度随界面弹性毛细管数呈现出不同的变化趋势，这归因于毛细波上的额外耗散以及表面粘弹性对喷射形成的汇聚流的延迟和阻力。我们的工作可能会增进对受污染液体表面气泡破裂动力学的理解，并揭示表面粘弹性对气泡破裂气溶胶产生的潜在影响。
