טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentKatsir Yael
SubjectLiquid Film Drainage in Bubble Coalescence
DepartmentDepartment of Chemical Engineering
Supervisor Professor Emeritus Abraham Marmur
Full Thesis textFull thesis text - English Version


Abstract

Our main objective was to understand inhibition of bubble coalescence either in certain electrolyte solutions by various methods or in sea-water by breaking waves. We present our observations using custom-built systems: (1) bubble-column apparatus, which enables observation of single bubbles and control of the approach speed; (2) a simple apparatus of inclined liquid-jet into a relatively still horizontal liquid surface in a tank. Air-bubble coalescence following quasi-static approach was found to qualitatively and quantitatively obey the DLVO theory. But following the dynamic approach, inhibition of bubble coalescence in electrolyte solutions appears to be observed clearly just in multi-bubble systems. Hence, concentration profiles of the electrolyte's ion in the EDL were calculated considering mass balance, Gibbs-Duhem, and film thickness drainage (which assume to be faster than concentration equilibration).