Studying foam dynamics in levitated, dry and wet foams using diffusing wave spectroscopy

Abstract

We use diffusing wave spectroscopy to study the microscopic dynamics of foams. These foams are levitated diamagnetically, such that very high liquid fractions can be achieved. We find that at low liquid fraction the dynamics is dominated by local rearrangements, whereas at high liquid fraction the movement of bubbles is ballistic and large scale rearrangements are absent. This change in the microscopic dynamics coincides with a change in the scaling of coarsening on increasing the liquid fraction that we have found earlier.