Molecular ordering and phase transitions in alkanol monolayers at the water-hexane interface

Molecular ordering and phase transitions in alkanol monolayers at the water-hexane interface were studied using x-ray reflectivity, x-ray off-specular diffuse scattering, and interfacial tension measurements. The alkanols which were adsorbed to the interface were found to form the monolayer. A transition was observed to take place between a low temperature interface that is nearly fully covered with alkanols to a higher temperature interface with a much lower density of alkanols. The presence of domains represented the appearance of a spatially inhomogeneous phase rather than the coexistense of two homogeneous phases.