Do the interfacial fluidities of cationic reverse micelles enhance with an increase in the water content?
The role of cosurfactant and water on the interfacial fluidities of reverse micelles formed with the cationic surfactant, cetyltrimethylammonium bromide (CTAB) has been examined by measuring the fluorescence anisotropies of two structurally similar ionic solutes, rhodamine 110 and fluorescein. For this purpose, reverse micellar systems with (CTAB/1-pentanol/cyclohexane/water) and without a cosurfactant (CTAB/chloroform-isooctane/water) have been chosen. In this study, the mole ratio of water to surfactant W has been varied in the region of 4-25. Experimental results indicate that the average reorientation time of the probe, which is a measure of the fluidity near the interfacial region, decreases by a factor of 1.5 and 1.4 for rhodamine 110 and fluorescein, respectively, as W goes up from 5 to 25 in CTAB/1-pentanol/cyclohexane/water reverse micellar system. In contrast, the average reorientation time, remains invariant for both the probe molecules in CTAB/chloroform-isooctane/water rev
