高粘性な粘弾性流体中を上昇する気泡の気液界面から発現する糸状形状に関する考察

抄録

The motion of single bubbles rising in a highly viscous hydrophobically modified alkali-soluble emulsion (HASE) polymer solution is experimentally examined. In the experiment, a 1.6 wt% HASE polymer solution, which is adjusted to pH ≈ 7.0 by adding a sodium hydroxide solution, is used. In this study, we focus on the long threadlike shapes formed at the bottom of a bubble. Our observations are recorded using two high-speed video cameras. The morphology of trailing edges with threadlike branches is sensitive to the bubble size. For increasing bubble size, the number of threadlike branches observed also increases; more than 10 threadlike-branches are observed for large sized bubbles. Besides reporting on bubble morphology for single bubbles rising in a highly viscous HASE material, we also report on a discontinuity change in the relation of bubble rise velocity vs bubble volume.