Department of Mechanical Engineering, Boston University, Boston, Massachusetts 02215, USA.
Phys Rev Lett. 2023 Feb 3;130(5):054001. doi: 10.1103/PhysRevLett.130.054001.
When small bubbles rupture in a contaminated water source, the resulting liquid jet breaks up into droplets that can aerosolize solid particulates such as bacteria, viruses, and microplastics. Particles collected on the bubble surface have the potential to become highly concentrated in the jet drops, dramatically increasing their impact. It has been assumed that only particles small enough to fit within a thin microlayer surrounding the bubble can be transported into its influential top jet drop. Yet here, we demonstrate that not only can larger particles be transported into this jet drop, but also that these particles can exceed previous enrichment measurements. Through experiments and simulations, we identify the prerupture location of the liquid that develops into the top jet drop and model how interfacial rearrangement combines with the bubble size, particle size, and the angular distribution of particles on the bubble surface to set the particle enrichment.
当小气泡在受污染的水源中破裂时,产生的液体射流会分裂成液滴,这些液滴可以使细菌、病毒和微塑料等固体颗粒气溶胶化。气泡表面收集的颗粒有可能在射流液滴中高度浓缩,从而显著增加其影响。一直以来,人们都认为只有小到足以进入气泡周围的薄微层的颗粒才能被输送到其有影响力的顶部射流液滴中。然而,在这里,我们证明了不仅较小的颗粒可以被输送到这个射流液滴中,而且这些颗粒的浓度可以超过以前的富集测量值。通过实验和模拟,我们确定了形成顶部射流液滴的液体在破裂前的位置,并建立了模型来研究界面重组如何与气泡尺寸、颗粒尺寸以及气泡表面上颗粒的角分布相结合来设定颗粒的富集程度。