Bubble Solid Interaction

Abstract

The interaction of a bubble with solid surfaces, hydrophobic and hydrophilic, was investigated. When a bubble approaches towards a solid surface, a thin liquid film forms between them. The liquid in the film drains until an instability forms and film ruptures resulting in a three phase contact (TPC). Following rupture, the TPC line spreads on the solid surface. In the present study, glycerol-water solutions with varying percentages of water were used to investigate the effect of viscosity. Experiments were carried out with varying bubble size. The rupture and TPC line movement were recorded by high-speed digital video camera. The dependence of the TPC line movement on different parameters was investigated. The experimental results were compared with the existing theories for the TPC line movement. An empirical equation was developed to predict the TPC line movement. Formation or rupturing of the intervening film in case of a hydrophilic surfaces, which were glass surface cleaned by six cleaning techniques, was investigated. It was shown that a stable film forms for acid or alkali cleaning.