Bubble velocity jump discontinuity in polyacrylamide solutions: a photographic study

Abstract

 It has been established that in the presence of elastic as well as surface tension forces, a jump can occur in the bubble velocity-bubble volume plot. It was proposed that this phenomenon was the result of an elastic instability at the bubble interface, which drastically changes the local boundary conditions. The origin of this change was mainly attributed to the magnitude of the elastic forces, which can extract surface active impurities at the gas-liquid interface. The purpose of this paper is to present photographic evidence of this hypothesis and to confirm past results.