Solubilization of pure and aqueous 1,2,3-propanetriol by reverse aggregates of Aerosol-OT in isooctane probed by FTIR and H-1 NMR spectroscopy

Solubilization of 1,2,3-propanetriol, PT, and its aqueous solution, PT-W, ( W = water), by reverse aggregates of sodium bis(2-ethylhexyl) sulfosuccinat e, Aerosol-OT or AOT, in isooctane has been studied by FTIR and H-1 NMR spe ctroscopy, and the results were compared with those of solubilization of 1, 2-ethanediol, ED, and W by the same surfactant. Curve fitting of the IR nu (OD) band of aggregate solubilized PT or PT SW showed the presence of a mai n peak arid a smaller one. Dependence on [solubilizate]/[AOT] of H-1 NMR ch emical shifts, delta (proton) of solubilized PT, PT-W, as well as the surfa ctant protons showed monotonic increase or decrease. Both spectroscopic tec hniques indicated the following order of interaction with AOT: PT > ED > W. Over the entire range of [solubilizate]/[AOT], the main nu (OD) peak areas correspond to 88 +/- 2%, and 90 +/- 2% of the total peak areas for PT, and PT-W, respectively. This result shows that aggregate-solubilize PT or PT-W do not seem to coexist in "layers" of different structures, as suggested b y the multistate solubilization model.