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

The effects of compressed CO(2) 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.