The destabilization of froth by solids. II. The rate-determining step

Abstract Hydrophobic quartz and hydrophobic galena were found to destabilize the froth formed when an aqueous solution of non-ionic surfactant was shaken. A relationship between the particle size and the mass of solids required to effect a constant degree of stabilization of the froth was found to hold for hydrophobic quartz from 4 μm to 400 μm and for xanthated galena from 15 μm to 38 μm. This relationship shows that the natural thinning rate of a film between bubbles in a froth is the rate-determining step in the rupturing of the film.