The dynamic motion of single bubbles with unique shapes rising freely in hydrophobically modified alkali-soluble emulsion polymer solutions

Abstract

The motion of single bubbles rising through hydrophobically modified alkali-soluble emulsion polymer (HASE) solutions is experimentally examined. In this study, we prepare 1.0, 1.1, and 1.6 wt. % HASE solutions and the bubble rise motion is explored depending on the value of the suspending viscosity. Consequently, in a HASE solution with high-viscosity, we find threadlike thin and long branches formed at the trailing edge of the bubble. For moderate-viscosity, we observe bubbles with long and large trailing skirts. These are different from those for Newtonian fluid systems. In the case of low-viscosity, many thread-shaped tails are formed along the bottom edge of the bubble. We observe that threadlike tails irregularly or regularly (unidirectionally) rotate depending on the bubble size along the bottom edge of the bubble. In addition, the bubble rise motion is considered based on modified physical parameters and the terminal bubble rise velocity. In our experimental conditions, it is reported that a jump discontinuity of the terminal bubble rise velocity has not occurred.