Compressed CO2 in AOT reverse micellar solution:: Effect on stability, percolation, and size

The effects of compressed CO2 in sodium bis-2-ethylhexylsulfosuccinate (AOT)/decane reversed micellar solution on the stability of the micelles, interface, and micelle/micelle interactions were studied. It was demonstrated that the compressed gas could increase the solubilization of water in this system. The formation of the stabilized one-phase microemulsion was confirmed by conductivity measurements. A shift in percolation threshold to higher temperature was observed after compressed gas was added. The gyration radius (R-g) of the reverse micelles was determined using, SAXS. R-g increases with the addition of water, while it decreases appreciably with increasing pressure of compressed gas at fixed W-0. These results were interpreted in terms of an increase of the rigidity of the interface layer and a decrease of the interdroplet attraction. The results of this work provide useful information to get insight into the mechanism of cosurfactants to stabilize reverse micelles.