Hydrophobicity of air-bubbles in water

摘要

A thin film balance was used to determine theequilibrium film thicknesses of dodecylammonium data wereanalyzed in view the extended DLVO theory. The results showthat air bubbles are most hydrophobic in the absence ofsurfactant. The hydrophobic force decreases with increasingsurfactant concentration, and becomes comparable to the vander Waals force at approximately 2x10~(-3) M. At higherconcentrations, air bubble becomes hydrophilic due to theappearance of hydration force. Consideration of hydrophobicforce helps explain the rupture thicknesses that are larger thanpredicted by the classical DLVO theory.