【Abstract】 This study was about the effect of pH and small molecule organic compound on the phase behavior of SDS/CTAB/H 2O mixture.The ATPS regions and LC regions were mainly discussed.It was shown that when the pH of the system was not neutral LC regions enlarged but ATPS regions reduced.In the condition of strong acid,the ATPS a region in which anionic surfactant in excess would extend to the SDS-H 2O axis of the pseudo phase diagram of SDS/CTAB/H 2O system.Small molecule organic compound that was not ionized in aqueous solution combined with water in the form of hydrogen bond.For this reason,the hydration of surfactant decrease and cationic surfactant and anionic surfactant integrate to form precipitate.So the surfactant-rich phase of ATPS showed milky white and the polarizing appearance was not clear.更多还原