Microbubble dissolution in a multigas environment.

Area of Science:

• Fluid dynamics
• Materials science
• Biomedical engineering

Background:

• Microbubbles are prevalent in nature and industry.
• Understanding microbubble fate is crucial for applications like ultrasound contrast agents.

Purpose of the Study:

• To theoretically and experimentally determine microbubble behavior in multi-gas media.
• To expand existing models to include multiple gas species.
• To investigate the influence of shell composition on microbubble dynamics.

Main Methods:

• Developed a theoretical model expanding on Epstein and Plesset's analysis for multi-gas environments.
• Created an experimental system using a hollow fiber in a perfusion chamber for controlled microbubble environment.
• Verified the model using sulfur hexafluoride (SF(6)) microbubbles coated with sodium dodecyl sulfate (SDS) and dibehenoylphosphatidylcholine.

Main Results:

• SDS-coated microbubbles initially grew due to gas influx before dissolving.
• Lipid-coated microbubbles showed diminished initial growth and complex, three-stage dissolution.
• Observed increased shell rigidity during dissolution, affecting microbubble stability and acoustic properties.

Conclusions:

• Microbubble behavior is significantly influenced by shell composition and dynamic surface tension.
• The developed model accurately predicts microbubble fate in multi-gas environments.
• Findings have implications for optimizing microbubble-based technologies, particularly in acoustics and drug delivery.