Coalescence Dynamics of Particle-Laden Bubbles

Area of Science:

• Colloid and Surface Science
• Fluid Dynamics
• Materials Science

Background:

• Particle-stabilized liquid foams are ubiquitous in nature and industry.
• Understanding bubble coalescence is key to controlling foam properties and stability.
• The role of particles in modifying interfacial dynamics during coalescence remains an active research area.

Purpose of the Study:

• To experimentally investigate the coalescence dynamics of microparticle-laden bubbles.
• To quantify interparticle forces within the neck region during early-stage coalescence.
• To elucidate the mechanism by which particles influence bubble coalescence and foam stability.

Main Methods:

• High-speed photography was employed to capture bubble coalescence events.
• Experimental observations focused on the early stages of neck formation.
• Interparticle forces in the neck region were calculated based on observed dynamics.

Main Results:

• A monolayer of silica particles on bubble surfaces was observed to hinder air neck growth.
• This hindrance is attributed to increased surface pressure from particle interactions.
• Apparent surface tension in the neck region increases with time and decreases with larger particle size.

Conclusions:

• Particle-surface interactions significantly influence the dynamics of bubble coalescence.
• The findings provide insights into particle-induced stabilization mechanisms in liquid foams.
• This study enhances understanding of particle effects on fast-deforming interfaces.