8/5/2024 Taylor Parks
Written by Taylor Parks
Assistant Professor Jie Feng recently won a $320K grant from the National Science Foundation’s Chemical, Bioengineering, Environmental and Transport Systems (CBET) program to study the implications of bubble bursting dynamics on the spread and aerosolization of contaminants.
Building on previous research on bubble bursting dynamics, Feng’s study, “Dynamics and transport of compound multiphase bubble rising and bursting,” for which he is the sole PI, will experimentally and theoretically investigate the formation of multiphase bubbles (i.e., gas-liquid bubbles coated by a distinct third compound) and the subsequent result of these bubbles rising and bursting.
In nature, bubbles can be formed abundantly by physical processes such as waves breaking, raindrops impacting surfaces, and gas releasing from natural seeps. Bubbles can also be intentionally utilized in a variety of industrial processes involving gas fluxing, such as bioreactors and wastewater treatment. When these bubbles rise, they may acquire a coating of chemical (e.g., oil, toxins, microplastics) or biological (e.g., bacterial, viral) contaminants from the water.
“My research group has developed a method for generating multiphase bubbles in a controllable way,” Feng said. “We can manipulate the coating thickness for each experiment, which will allow us to study the bubble formation systematically. From our preliminary results, we have already observed unexpected and intriguing bubble dynamics in the multiphase system, which require further investigation.”
Whether natural or manufactured, multiphase bubbles eventually burst when they ascend to the air-water interface. The burst results in tiny, contaminant-laden droplets, which in turn causes the contaminant coating layer to become aerosolized and, typically, spread further. Therefore, bubble rising and bursting dynamics play a vital role in understanding, controlling, and mitigating contaminant-laden aerosol emission.
“Understanding how contaminants are spread through aerosolization could improve the ways that we mitigate pollution in the future,” Feng said. In the case of microplastics, which, when aerosolized, can spread far beyond initial pollution sites, insights toward the dynamics driving the aerosolization process could inform strategies for reducing the spread of microplastics pollution and controlling its impact on the surrounding area.
“Insights from our study could help to develop personal protection gear that prevents users from breathing in contaminants near sites where aerosolization occurs,” Feng said as an example.
Feng and his graduate researchers will use particle tracking and image velocimetry to characterize the rising dynamics of a compound multiphase bubble. They will follow these efforts by using high-speed imaging and direct numerical simulation to characterize the bursting dynamics of these bubbles. For both objectives, Feng will employ compounds that mimic ubiquitous contaminants in nature and engineering settings.
For more on Feng’s work in bubble bursting dynamics, see his articles in Nature Physics, Physical Review Letters, Nature Communications, and Nano Letters.