Partial phase diagram obtained at 70°C for mixtures of toluene, AOT/SDS (2/1 w/w), and 0.9 M Zn(NO₃)₂ aqueous solution. The one-phase microemulsion region (1) is located between the surfactants mixture/toluene axis and the solid line; here, lines A, B, and C indicate where conductivity measurements were performed to examine the structure of the microemulsions. Solid triangles indicate the compositions where the precipitation reactions were made.