MEASUREMENT OF ULTRALOW INTERFACIAL-TENSION WITH APPLICATION TO SURFACTANT-ENHANCED ALKALINE SYSTEMS

This paper discusses the dynamic interfacial tension (IFT) variation i n a system containing an acidic oil in contact with an alkaline soluti on which may contain a preformed surfactant. A modified technique simi lar, in principle, to the sessile drop technique is used for monitorin g the dynamic IFT which is in the ultralow range. The technique is the n applied for measuring ultralow IFTs in systems consisting of acidic oils and alkaline solutions containing preformed surfactants. The effe ct of aqueous phase pH, surfactant concentration, and oil phase acid c oncentration on the dynamic IFT variation in these systems is determin ed by using this technique.