Topological transition dynamics in a strained bubble cluster

Abstract

We study experimentally the dynamics of strain-induced T1 neighbour switching in clusters of 3D bubbles. To determine the physico-chemical processes that set the time scale of such rearrangements, foaming solutions of a wide range of well characterized bulk and interfacial rheological properties are used. At low strain rates, the time scale is set by a balance between surface tension and surface viscous forces, and we present a simple physical model that explains these findings, on the basis of previous experimental and theoretical work with 2D foams.¹ At higher strain rates, rearrangement dynamics are driven by the applied strain. In a wider context, our study of T1s in bubble clusters provides insight into the structural relaxations that accompany the flow of 3D foams.