Microemulsions Using Hexaethylene Glycol Mono-n-dodecyl Ether Nonionic Surfactant and Small Amount of Ionic Surfactants

Abstract

Abstract The influence of small addition of ionic surfactant such as sodium dodecyl sulfate (SDS) and carboxylate ethoxyle (TDC) to nonionic surfactant hexaethylene glycol mono-n-dodecyl ether (C12E6) on the microemulsions formed in the system water/decane/surfactant was studied. An empirical description of the phase behaviour is presented that permits to determine the PIT, and what efficiency of the surfactants to expect. The investigation showed an expected rise in the temperature at which maximum solubility was observed (PIT), and a pronounced extension of the solubility area was also observed. In addition, the temperature stability of these microemulsions was improved. The structural study of the system water/(C12E6+1% TDC) shows that the liquid crystal phase is lamellar at 45°C. It's structural parameters are determined by small angle X-ray scattering. The study of lamellar phase allows the description of the evolution of the surfactant chains conformation.