The state of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reversed micelles has been investigated by Fourier transform infrared spectroscopy with an attenuated total reflection (ATR) accessory. 2D correlation spectroscopy revealed that a process of AOT molecules transforming from trans conformation into gauche conformation exists during heating. The quantitative analysis of the C＝O stretching vibration band shows that before 38 ℃, the gauche conformation transformed into the trans conformation, and after 38 ℃, the trans conformation transformed into the gauche conformation instead. The reversed micelles have the maximum size and lowest energy at the temperature of 38 ℃.

Key words: sodium bis(2-ethylhexyl) sulfosuccinate, reversed micelle, attenuated total reflection (ATR), 2D correlation spectroscopy