Effect of alcohol frothing agents on the coalescence of bubbles coated with hydrophobized silica particles

摘要

The stability of capillary-pinned bubble pairs covered with hydrophobized particles in aqueous solutions of 1-pentanol or methyl isobutyl carbinol (MIBC) was studied using high-speed cinematography. Glass particles were first rendered hydrophobic by covalently bonding a linear alcohol onto the solid interface to achieve a specific hydrophobicity (i.e, contact angle of 43 degrees measured with the captive bubble on a treated wafer) and effectively avoid the presence of any mobile hydrophobizing surfactant. The resistance to coalescence of the bubbles was measured at different frother concentrations and for various initial bubble interfacial areas covered by particles; with particle coverage not exceeding the contact region between the bubbles.