Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
Nat Commun. 2021 Nov 2;12(1):6305. doi: 10.1038/s41467-021-26382-w.
Bursting of bubbles at a liquid surface is ubiquitous in a wide range of physical, biological, and geological phenomena, as a key source of aerosol droplets for mass transport across the interface. However, how a structurally complex interface, widely present in nature, mediates the bursting process remains largely unknown. Here, we document the bubble-bursting jet dynamics at an oil-covered aqueous surface, which typifies the sea surface microlayer as well as an oil spill on the ocean. The jet tip radius and velocity are altered with even a thin oil layer, and oily aerosol droplets are produced. We provide evidence that the coupling of oil spreading and cavity collapse dynamics results in a multi-phase jet and the follow-up droplet size change. The oil spreading influences the effective viscous damping, and scaling laws are proposed to quantify the jetting dynamics. Our study not only advances the fundamental understanding of bubble bursting dynamics, but also may shed light on the airborne transmission of organic matters in nature related to aerosol production.
液面上的气泡破裂在广泛的物理、生物和地质现象中普遍存在，是界面跨越质量传输的气溶胶液滴的主要来源。然而，结构复杂的界面是如何介导破裂过程的，这在很大程度上仍是未知的。在这里，我们记录了油覆盖水表面上的气泡破裂射流动力学，这典型地代表了海洋表面微层以及海洋上的溢油。即使是很薄的油层也会改变射流尖端半径和速度，并产生油性气溶胶液滴。我们提供的证据表明，油的扩散和空穴坍塌动力学的耦合导致了多相射流和后续的液滴尺寸变化。油的扩散影响了有效粘性阻尼，并且提出了标度律来量化射流动力学。我们的研究不仅推进了对气泡破裂动力学的基本认识，而且可能揭示了与气溶胶产生有关的自然有机物的空气传播。
