Effect of alcohol on equilibrium and dynamic behavior of a system containing a non-ionic surfactant and triolein

Abstract Phase behavior studies showed that the addition of tert -amyl alcohol (TAA) to the system comprising n -dodecyltetraoxy-ethylene monoether (C 12 E 4 ), triolein and water lowered the temperature range for formation of the D phase, a surfactant-rich liquid capable of solubilizing appreciable amounts of triolein. In the absence of TAA, the D′ phase, which solubilizes little triolein, was observed instead. The D phase also formed as an intemediate phase when C 12 E 4 -TAA-water mixtures were brought into contact with triolein at 50°C. Apparently the alcohol increases disorder in the hydrocarbon chain region of the surfactant films and thereby permits incorporation of the relatively large triolein molecules. Although TAA did not improve triolein removal from fabrics, it is possible that other additives which also promote formation or the D phase but have lower solubility in water would be more effective.