Experimental studies of bubble dynamics in a slowly driven monolayer foam

We report a study of the topological rearrangements in a Langmuir-monolayer foam subjected to a constant rate of strain. Measurements of the size distribution for the rearrangements are compared with three simulations that find a power-law distribution for a gas area fraction phi = 1, a power law for phi = 0.84, and an exponential cutoff in the size distribution. No evidence for power-law scaling is found in the experiments for 0.85 less than or equal to phi less than or equal to 0.95. These comparisons suggest that the nature of the dissipative mechanisms is an important factor in the determination of the size distribution.