Three-phase Contact Expansion During the Bubble Adhesion on an Inclined Plane

Abstract

The bubble attachment onto a collecting surface is a common natural phenomenon and the bubble-particle interactions are used in numerous industrial applications. The adhesion process between a small single rising bubble and a stationary solid particle with hydrophobic surface in stagnant liquid is studied in this project. The real particle is replaced by a prism with an inclined plane representing a spherical particle with infinite diameter. Experiments were performed using a freely rising bubble method. The influence of bubble size and type of bubble surface mobility was studied and described both experimentally and theoretically. The molecular-kinetic and hydrodynamic models were used for theoretical description of the TPC expansion. According to our results, hydrodynamic model is not appropriate for the TPC line calculation. The value of its adjustable parameter is not in accordance with physical assumption. The molecular-kinetic model gives better results. Two adjustable parameters (the frequency of the molecular displacement and the average jumping distance) were calculated and their values correspond to the physical assumptions. It was found that the bubble size is the most important parameter influencing the TPC line expansion. The influence of bubble surface mobility is surprisingly low. Only the frequency of the molecular displacement differs for bubbles with mobile or immobile surface. This conclusion corresponds to the theoretical assumption that the presence of surface active agents decelerates the bubble motion.