We report here that two aqueous phases were formed when cationic surfactant dodecyl triethylammonium bromide (C12NE) was mixed with anionic surfactant sodium dodecylsulfate (SDS) by ratio of 1.6:1(v/v). This phenomena had been called as aqueous surfactant two phases (AS2P). If cationic surfactant was in excess in the mixture, it was called cationic aqueous two phases (CA2P). Pyrene fluorescence probe has been used for studying the micelle properties of CA2P, and evaluating the micelle micropolarity of CA2P. The microviscosity of CA2P was evaluated by determining the degree of fluorescence polarization of rhodamine B in CA2P. In the upper phase, the molar ratio of cationic-anionic surfactants was near 1:1. The molecule arrangement of the micelle was compact and regular, and microviscosity was high, due to the electrostatic and hydrophobic interactions. Whereas in the lower phase, the molar ratio of cationic- anionic surfactants deviated significantly from 1:1. The organization of the space arrayment of micelle was less compact than that of the upper phase, and its microviscosity was low.

Key words: MICELLE, SURFACTANTS, RHODAMINE B, PYRENE