SANS experiments on micellar nematic mesophases

Overview & Synopsis

Lyotropic Nematics are liquid crystalline mixtures characterized by anisotropic aggregates of amphiphilic molecules with finite shape and long range orientational but no positional order. They are distinguished according to their macroscopic properties in positive and negative uniaxial nematics and in biaxial nematics. Very few notices are available on the structure and on the evolution of the micelles through the different nematic mesophases. We have studied by Small Angle Neutrons Scattering the potassium laurate, decylammonium hydrochloride, water system which was found to exhibit the three nematic phases as a function of temperature and concentration. SANS preliminary experiments were performed at PAXY spectrometer of Orphée reactor at Saclay on adequate combinations of fully deuterated components.