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

TL;DR

This study uses synchrotron X-ray scattering to analyze the molecular structure and phase transitions of n-triacontanol films at the n-hexadecane-water interface, revealing multilayer adsorption below the vapor-liquid transition.

Contribution

It provides new insights into the phase behavior and multilayer adsorption phenomena of long-chain alcohol films at oil-water interfaces using advanced X-ray techniques.

Findings

Multilayer adsorption occurs below the vapor-liquid transition temperature.

Transition related to micelle concentration changes in the surface layer.

Molecular structure varies with phase state at the interface.

Abstract

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 different its phase states has been studied by the method of diffuse X-ray scattering. 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 {\AA} thick.