Studies of Synergism/Antagonism for Lowering Dynamic Interfacial Tensions in Surfactant/Alkali/Acidic Oil Systems, Part 2: Synergism/Antagonism in Binary Surfactant Mixtures

Abstract

Experimental studies are conducted in order to elucidate the mechanisms responsible for synergism/antagonism for lowering dynamic interfacial tension in hydrocarbons/binary surfactant mixtures/brine systems. The dynamic interfacial tensions between hydrocarbons of different alkane carbon numbers (from 6 to 14) and solutions of binary surfactant mixtures were measured. We found that the synergism/antagonism for interfacial tension reduction in binary surfactant mixtures having low interfacial tension values was influenced by the alkane carbon number of oil phase, hydrophilic–lipophilic ability of surfactant, and NaCl concentration. A new explanation in view of interactions among surfactant molecules, oil molecules, and water molecules is provided.