Form and Structure Factors of Water/AOT/Oil Microemulsions from Synchrotron SAXS

Synchrotron small angle X‐ray scattering (SAXS) measurements were performed on water/AOT/n‐hexane w/o microemulsions with w0 ( = [H2O]/[AOT]) values ranging from about 0 to 100. The volume fraction of solute and the temperature were varied in a wide range. The scattering behaviour (form and structure factor) could be explained on the basis of a pseudo hard sphere model, where the spheres were allowed to be spheroidally deformed to a certain extent. We have shown that these deformations become larger as the lower consolute point of the mixture is approached. Furthermore, we have demonstrated that the radius of gyration is temperature independent, and that it depends linearly on w0. The w0‐dependence of the scattering intensity could be explained on the basis of the droplet model.