Surfactant-free oil/water and bicontinuous microemulsion composed of benzene,ethanol and water

Generally,a microemulsion consists of oil,water,surfactant and sometimes cosurfactant.Herein,we report a novel suffactant-free microemulsion（denoted as SFME） composed of benzene,water and ethanol without the amphiphilic molecular structure of traditional surfactant.The phase behavior of the ternary system was investigated,finding that there were a single-phase region and a two-phase region in ternary phase diagram.The electrical conductivity measurement was employed to investigate the microregion of the single-phase region,and a bicontinuous microregion and a benzene-in-water（O/W） microemulsion microregion were identified,which was confirmed by freeze-fracture transmission electron microscopy（FF-TEM） observations.The sizes of the microemulsion droplets are in the range of 20-50 nm.