Wang Hao, Brito-Parada Pablo R
Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
Langmuir. 2020 May 19;36(19):5394-5399. doi: 10.1021/acs.langmuir.0c00938. Epub 2020 May 8.
Understanding the coalescence of particle-laden bubbles is crucial to our understanding of the role of particles in stabilizing liquid foams. In this work, the coalescence of microparticle-laden bubbles is studied experimentally using high-speed photography. In particular, the interparticle forces in the neck region during the early stage of bubble coalescence are calculated. The results indicate that a monolayer of silica particles coating the bubble surfaces hinders the growth dynamics of the air neck formed between the coalescing bubbles. We postulate that the decrease in the growth dynamics is due to the surface pressure caused by the particle interaction after the initiation of bubble coalescence. We identify that the apparent surface tension in the neck region increases with time for particle-laden bubbles and is lower for larger particle sizes. These findings enhance our understanding of the role of particles on the dynamics of fast deforming interfaces.
了解载有颗粒的气泡的聚并对于我们理解颗粒在稳定液体泡沫中的作用至关重要。在这项工作中，使用高速摄影对载有微粒的气泡的聚并进行了实验研究。特别地，计算了气泡聚并早期颈部区域的颗粒间力。结果表明，覆盖在气泡表面的单层二氧化硅颗粒阻碍了聚并气泡之间形成的气颈的生长动力学。我们推测生长动力学的降低是由于气泡聚并开始后颗粒相互作用引起的表面压力。我们发现，载有颗粒的气泡颈部区域的表观表面张力随时间增加，且对于较大粒径的颗粒较低。这些发现加深了我们对颗粒在快速变形界面动力学中作用的理解。
