Micro-emulsion usually consists of water

oil

surfactants and co-surfactants

and each component has an effect on the phase behavior and solubilization of the micro-emulsion. When the surfactant in the micro-emulsion system is quaternary ammonium cationic Gemini surfactant

the surfactant mainly combines with the anions in the salt. With the increase of salt concentration

the phase transformation of Winsor I → Winsor Ⅲ → Winsor Ⅱ occurred

but the optimum salinity and salt width are different because of the type of salt. The effects of 5 different kinds of monovalent anions

including C

6

H

5

SO

3

-

I

-

Br

-

NO

3

-

and Cl

-

on the phase behavior and solubilization of quaternary ammonium cationic Gemini micro-emulsion are researched by Winsor phase diagram. It is found that the effects of organic anions C

6

H

5

SO

3

-

and I

-

on the phase behavior and solubilization of quaternary ammonium cationic Gemini micro-emulsion are most significant

and the effects of Br

-

NO

3

-

and Cl

-

are less significant. Meanwhile

when the opt

imum solubilization is achieved

the amount of sodium benzoate is the least

indicating that the organic anion has stronger self-organization behavior with quaternary ammonium cationic Gemini surfactants.