Abstract
The middle-phase microemulsion potentially for oil recovery is often produced by using alcohol as a co-surfactant. The objective of this study is to connect the changes of this middle-phase with the resulting minimum interfacial tensions upon adding the alcohol to the systems containing brine, an anionic surfactant and different alkanes. The results demonstrated a reduction in the interfacial tensions with either increasing alcohol concentration or decreasing the alkane carbon number. The observed trends were expressed by a simple correlation between the minimum interfacial tensions and optimal salinities. This correlation can be used to select the optimum surfactant/alcohol formulations for soil remediation.
