Effect of Surfactant upon Capillary Adhesion in Four-phase Systems

Abstract

Liquid bridges of aqueous sodium dodecyl sulphate solutions with different concentration between polytetrafluoro ethylene and pyrex glass surface have been experimentally investigated. The drop distribution isotherms are of the same type, their general shape being independent of the surfactant concentration but the characteristic points as the critical drop mass for total adherence and the constant drop mass corresponding to the steady state strongly depend on the surfactant concentration. The stability of the bridges as well as the formation of satellite droplets after breakdown of the bridge have been interpreted in terms of capillary waves. A simple energetic model consideration is proposed to explain effects caused by hysteresis