Abstract:

The isothermal phase diagram for the system sodium dodecyle sulfonate/n-butanol/20% styrene/water has been determined at 40 ℃ The freeze fracture electron microscope, ESR, FT-IR have been used for determining the structures of microemulsions. The investigation shows that, with the increase of H2O-content the bicontinuous structural microemulsions determined by conductivity measurement undergo a change from W/O to bicontinuous (BC) and to O/W when the content of styrene is constant (20%). The stretching vibration and the bending vibration frequencies of OH in W/O microemulsions are less than those in O/W microemulsions, which indicates that the association strength of the hydrogen bonds in W/O microemulsions are much stronger than those in O/W microemulsions. The correlation times, τc, in O/W microemulsions, are longer than that in W/O microemulsions, indicating that the microviscosity in O/W microemulsion interface is higher than that in W/O microemulsion interface.

Key words: Sodium dodecyle sulfonate, ESR, FT-IR, Freeze fracture electron microscope, Structures