Tunable Photothermal Bubble Formation in Binary Liquids under Pulsed Laser Excitation

Area of Science:

• Physics
• Materials Science
• Fluid Dynamics

Background:

• Photothermal microbubbles are vital for microfluidics, medical tech, and materials engineering.
• Controlling microbubble growth is challenging due to complex heat and mass transfer phenomena.

Purpose of the Study:

• To systematically investigate microbubble expansion dynamics in ethanol-butanol solutions.
• To understand the influence of boiling point and viscosity on microbubble growth stages.

Main Methods:

• Systematic examination of microbubble expansion.
• Tuning the boiling point and viscosity of binary ethanol-butanol solutions.
• Analysis of liquid phase transition, dissolved gas diffusion, and convective heat transfer.

Main Results:

• Liquid phase transition, dissolved gas diffusion, and convective heat exchange govern distinct bubble growth stages.
• Boiling point affects the transition rate between rapid expansion and slow diffusion phases.
• Viscosity influences slow diffusion phase growth, with high viscosity involving dissolved gas diffusion and convective cooling.

Conclusions:

• The study elucidates the dominant mechanisms controlling microbubble evolution at different growth stages.
• Findings provide a basis for predicting and manipulating photothermal bubble dynamics in binary solutions.