On the existence of micellar positional correlations in a type I nematic lyomesophase: an X-ray diffraction experiment

The nematic type I lyomesophase of K laurate/ KC1/water is studied by X-ray diffraction and optical microscopy. X-ray diffraction patterns of samples in very thin capillaries and chemically surface-treated capillaries indicate the existence of a hexagonal array of cylindrical micelles. In normal conditions, where only one oriented band is observed, it is possible to describe the lyomesophase structure as nematic. An analysis of the band width is made by comparing the experimental scattering curves with theoretical expressions obtained from different models. This analysis indicates that micellar positional correlations have to be introduced to explain the experimental results.