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 $\phi =1\mathrm{}$, a power law for $\phi =0.84\mathrm{}$, and an exponential cutoff in the size distribution. No evidence for power-law scaling is found in the experiments for $0.85\le \phi \le 0.95$. These comparisons suggest that the nature of the dissipative mechanisms is an important factor in the determination of the size distribution.