Bubble motion measurements during foam drainage and coarsening

Area of Science:

• Colloid and Surface Science
• Fluid Dynamics
• Materials Science

Background:

• Foam drainage is crucial for industrial processes.
• Understanding bubble dynamics provides insights into foam behavior.

Purpose of the Study:

• To investigate bubble motion during free foam drainage.
• To correlate bubble movement with liquid flow and foam coarsening.
• To explore gas diffusion effects on foam expansion.

Main Methods:

• Tracking bubble upward motion over time and initial positions.
• Comparing bubble motion data with liquid drainage curves.
• Measuring liquid fraction using electrical conductimetry.

Main Results:

• Identified three types of bubble upward motion: constant speed, acceleration, and deceleration.
• Established a correlation between bubble motion and downward liquid flow.
• Demonstrated foam expansion due to gas diffusion when using less soluble gases.

Conclusions:

• Bubble motion analysis is a reliable method for determining foam drainage regimes.
• Foam coarsening and expansion are influenced by gas solubility and diffusion.
• This study offers a bubble-centric perspective on foam drainage and coarsening.