NUCLEAR MAGNETIC-RELAXATION NEAR THE NEMATIC-TO-ISOTROPIC TRANSITION IN MICELLAR SYSTEMS

Using the NMR F-19 technique, decay of the transverse magnetization (D TM) is studied over the nematic-to-isotropic liquid transition region for aqueous micellar solutions of cesium perfluorononanoate. Transvers e magnetization decay appears to be single-component in both nematic a nd isotropic phases and two-component in the two-phase region. Compone ntal composition of the DTM changes fastly near the low-temperature bo rder of the coexistence region but slowly near the high-temperature bo rder. Long exposition at fixed temperature leads to spatial phase sepa ration of the micellar system: the isotropic phase moves up while the nematic one drowns. It is argued that this fact is due to a difference in micellar concentrations between the two phases.