The Study of the Motion of Single Bubbles with Interfacial Fluctuation Phenomena Rising in a Viscoelastic Fluid

Abstract

The motion of single bubbles rising in hydrophobically modified alkali-soluble emulsion polymer (HASE) solutions is experimentally examined. In this study, HASE material is neutralized with sodium carbonate (Na₂CO₃), and 1.46 wt% and 1.36 wt% HASE solutions with pH = 9 are prepared. These solutions are viscoelastic fluids with weak non-Newtonian properties. When the equivalent volume diameter of the bubble exceeds a certain threshold value, characteristic phenomena that the gas-liquid interface, which was in a steady state, suddenly fluctuates can be observed for both HASE solutions. Once the bubble interface fluctuates, the bubble rise trajectory is non-linearly changed, and the rise velocity is increased because the bubble rise motion is accelerated by fluctuation. Characteristic interfacial phenomena do not always arise, and various fluctuation patterns are observed. The bubble rise motion observed in this study are unique phenomena that occur at the interface only when using HASE material neutralized Na₂CO₃.