Juggling bubbles in square capillaries: an experimental proof of non-pairwise bubble interactions

Area of Science:

• Physics of soft matter
• Fluid dynamics
• Materials science

Background:

• Physical properties of particle ensembles depend on interactions.
• Non-pairwise additive potentials are increasingly recognized for bubbles and drops.
• This challenges traditional simulations of soft grain packings.

Purpose of the Study:

• To experimentally confirm theoretical predictions of non-pairwise bubble interactions.
• To quantify bubble interactions in model foams.
• To validate a new non-pairwise interaction model.

Main Methods:

• Experiments with trains of equal-volume bubbles in square capillaries.
• Quantification of bubble interactions.
• Comparison with Surface Evolver simulations and analytical models.

Main Results:

• First experimental confirmation of non-pairwise bubble interactions.
• Quantitative agreement between experimental data and simulations.
• Interaction laws are well described by a non-pairwise model.

Conclusions:

• Bubble interactions in foams and emulsions are not pairwise additive.
• This finding has significant implications for the mechanical properties of foams and emulsions.
• The study validates a new theoretical framework for soft matter interactions.