Reverse micelles solubilizing DMSO and DMSO/water mixtures

Aerosol OT/cyclohexane reverse micelles solubilizing DMSO and DMSO/water mixtures have been investigated utilizing dynamic light scattering, IR spectroscopy and UV/vis absorption by a polarity probe. Without water, ∼2.5 DMSO molecules/AOT molecule are solubilized inside the micelles. Adding water to the reverse micelles significantly increases the DMSO solubilized. Reverse micelles solubilizing DMSO are larger than corresponding micelles containing an equal amount of water. IR spectra reveal water interacts both with DMSO and the surfactant head group. The polarity of DMSO increases inside the micelles, while the intramicellar DMSO/water polarity depends both on the ratio of the solvents and on micellar size.