J. H. Harwell, D. A. Sabatini and R. C. Knox, “Surfactants for Ground Water Remediation,” Colloids and Surfaces A: Physi-cochemical and Engineering Aspects, Vol. 151, No. 1, 1999, pp. 255-268.

has been cited by the following article:

• TITLE: Nanostructured Microemulsion Phase Behavior Using AOT or Extended Surfactant Combined with a Cationic Hydrotrope

  AUTHORS: Khalid Kanan, Hala Yousef, Ibrahim Kayali

  KEYWORDS: Middle Phase Microemulsion; Cationic Hydrotrope; Ultra Low Interfacial Tension

  JOURNAL NAME: Journal of Surface Engineered Materials and Advanced Technology, Vol.2 No.1, January 12, 2012

  ABSTRACT: The phase behavior for systems containing sodium bis (2-ethylhexyl sulfosuccinate) (AOT), with the cationic hydro-trope tetraethyl ammonium chloride (TEAC), in the presence of water and heptane were studied. Formulations of mi-croemulsion for such systems and for systems containing the so called “extended surfactant” were carried out at different salt concentrations. Anisotropy was detected using cross polarizers and polarized microscopy. Ultralow interfacial tension for microemulsion was measured, first theoretically using the Chun-Huh equation, and then experimentally using spinning drop experiments. The presence of short chain hydrotropes (TEAC) was found to destabilize the liquid crystalline region, observed in the AOT/water/heptane phase diagram. Ultralow interfacial tensions were observed for microemulsions formulated with surfactant concentrations as low as 0.5%, for both AOT and “extended surfactant” systems. The effect of temperature on the phase behavior of a microemulsion formed with AOT system was studied and found to behave in an opposite manner compared to the nonionic surfactant.