Jetting dynamics of bursting bubbles coated with protein–surfactant or polymeric compound layers

Barbhai, Sainath

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https://hdl.handle.net/2142/129322 Copy

Description

Title

Jetting dynamics of bursting bubbles coated with protein–surfactant or polymeric compound layers

Author(s)

Barbhai, Sainath

Issue Date

2025-05-08

Director of Research (if dissertation) or Advisor (if thesis)

Feng, Jie

Committee Member(s)

Freund, Jonathan

Department of Study

Aerospace Engineering

Discipline

Aerospace Engineering

Degree Granting Institution

University of Illinois Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

Bubble bursting, fluid mechanics, non-Newtonian rheology, aerosol generation

Abstract

Bursting of bubbles can be observed in a wide range of natural and industrial processes. The production of drops via bursting jets plays a critical role in the mass transport of chemical and biological contaminants, influencing scenarios from global climate dynamics to disease transmission. While the jetting dynamics of clean bubble bursting have been extensively studied over the past decade, real-world scenarios often involve contaminated bubbles. Due to their scavenging nature, bubbles frequently accumulate various contaminants that can potentially alter the jetting behavior and making it essential to understand the presence of surface/compound contamination. This thesis presents experimental investigations into bubble bursting at contaminated interfaces, focusing on viscoelastic surfaces composed of proteins, protein–surfactant mixtures, and polymeric coatings that mimic real-life contaminants. The objective is to understand how these rheologically complex interfacial layers alter jetting dynamics and influence drop ejection behavior. The first part of this thesis investigates the effect of surface viscoelasticity on top jet drop formation during bubble bursting. Specifically, we examine interfaces composed of globular proteins and mixed protein–surfactant solutions across a range of concentrations and controlled aging times. Our results show that the surface viscoelasticity imparted by these surface-active species significantly alters the jet ejection dynamics. This previously underexplored behavior highlights the distinct physicochemical properties of proteins and surfactants at the bubble interface that give rise to different interfacial stress responses, ultimately influencing jet formation mechanisms. Our findings may improve insight into the dynamics of bubble bursting on contaminated surfaces and highlight how surface viscoelastic properties influence aerosol generation. The second part of this thesis examines the influence of a polymeric compound layer on bubble bursting dynamics by systematically varying the compound layer volume fraction and polymer concentration. We investigate their effects on cavity collapse and subsequent jet formation. Our findings reveal that higher compound volume fractions lead to the generation of faster and more slender jets, attributed to enhanced damping of capillary waves and a reduction in the cavity cone angle during jet initiation. In contrast, increasing the polymer concentration introduces significant viscoelastic resistance, resulting in reduced jet velocities and suppression of drop formation. These discoveries may shed light on the underlying mechanisms of organic material transport through bubble-driven aerosolization, contributing to a deeper understanding of marine biological processes and environmental dynamics.

Graduation Semester

2025-05

Type of Resource

Thesis

Handle URL

https://hdl.handle.net/2142/129322

Copyright and License Information

© 2025 Sainath Barbhai

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