Phase behavior of W/O microemulsion system of CTAB/butanol/octane/water

The phase behavior of hexadecyl trimethyl ammonium bromide(CTAB)/butanol/ octane/H2O microemulsion system was studied according to the phase diagram theory of thermodynamics.The factors including cosurfactant(n-butanol),organic solvent(n-octane),temperature and mass concentration of salt solution(sodium tungstate) were analyzed based on the experimental research,and the parametric variation range of these parameters influencing the W/O microemulsion′s region was obtained.The structure of the microemulsion system was also studied by conductivity research,and the formative region and optimum proportion of the microemulsion system were determined.Experimental results show that cosurfactant, organic solvent and mass concentration of the salt solution are main factors influencing the microemulsion region formation,but temperature has no effect on the process.It indicates that the big and stable microemulsion region is formed when m(CTAB)∶m(n-butanol)=1∶2,m(CTAB+n-butanol)∶m(n-octane)=4∶6.