Coarsening Behavior and Coarsening Induced Rearrangements in Very Wet Quasi-2d Foams

Quasi 2-dimensional dry foams are made of polyhedral bubbles squashed between two parallel plates that are separated by thin films (TFs) as well as surface Plateau borders (SPBs) along the two plates. Bubbles coarsen because gas diffuses through their TFs and SPBs; gas diffuses more slowly through the SPBs which inflate in size as the liquid content of the foam increases and this slows coarsening in wetter foams. A generalized coarsening equation exists for quasi-2d dry foams with varying liquid content and it predicts average and individual bubble coarsening behavior [Chieco et al, arXiv:2010.06664]. Recently a prediction for the coarsening behavior for “wet” foams where bubbles are unjammed nearly touching circles with only liquid bridges separating them was developed. We flood foaming solution into a sample cell whose width is smaller than the capillary length of the solution so only liquid bridges separate bubbles and compare the coarsening of the bubbles to the expectation. Coarsening induced rearrangements are also studied in the wet systems. We present preliminary results on identifying the locations of rearrangements and explore using softness and machine learning to predict where/when they occur.