Nonaqueous microemulsion-containing ionic liquid [bmim][PF6] as polar microenvironment

The phase behavior of toluene/Triton X-100 (TX-100)/1-butyl-3-methylimidazolium hexafluorophosphate(bmim]PF6]) was studied. It was demonstrated that the single-phase microemulsion area covered about 75% of the phase diagram at 25 °C. Electrical conductivities of the system with different w (bmim]PF6]-to-TX-100 molar ratio) values were determined, and the results were used to locate the sub-regions of the single-phase microemulsion. The results showed that a transform from bmim]PF6]-in-oil (bmim]PF6]/O) microstructure via a bicontinuous region to an oil-in-bmim]PF6] (O/bmim]PF6]) microstructure occurred with the increase of Φ (weight fraction of TX-100 and bmim]PF6] in the system). The aggregate size of the reverse microemulsions of bmim]PF6]/O was determined using small-angle X-ray scattering. The results showed that the size of the reverse microemulsions depended markedly on the w values.