The effect of poly(ethylene oxide) on the characteristics of Triton X-100/1-butanol/ n-octane/water reverse micelles

 Nonionic poly(oxyethylene) surfactant with about ten ethylene oxide units and 1-butanol have been studied in reverse micelles with one nonpolar solvent(n-octane) at different water contents in the presence and in the absence of poly (ethylene oxide) (PEO) using two absorption probes, methyl orange and methyl blue MB and one spin probe, 5-doxylstearic acid. The study has focused attention on the effect of the addition of PEO on the phase behavior of the system, the state of water in the reverse micelles, and the locus of PEO solubilized in reverse micelles. In the presence of PEO, some PEO segments may penetrate into the interface close to the palisade layer of the reverse micelles and then replace some water molecules, which results in a less close arrangement between the chains of surfactants as well as between alcohol molecules. Received: 13 April 1999/Accepted in revised form: 5 November 1999