X-Ray Study of Thermotropic Mesophases of an Adsorbed n-Triacontanol Film at the n-Hexadecane–Water Interface

Using synchrotron radiation with a photon energy of 15 keV, the molecular structure of an adsorbed n-triacontanol layer at the n-hexadecane–water interface in its different phase states has been studied by the diffuse X-ray scattering method. The analysis of the experimental data shows that a transition to the multilayer adsorption occurs at a temperature below the two-dimensional vapor–liquid transition at the interface. This transition has been attributed to a feature in the temperature dependence of the concentration of micelles in a surface layer 100–200 Å thick.