Micellar anisometry in lyotropic uniaxial nematic phases studied by transversal NMR relaxation dispersion.
A new method, based on the measurement of the (23 )( )Na nuclei spin-spin NMR relaxation times ( T2 ), is proposed to investigate the shape of micelles in lyotropic nematic phases. We investigate the ternary lyotropic mixture of sodium dodecyl sulfate, 1-decanol, and water by using the NMR technique, measuring T2 in the two lyotropic uniaxial nematic phases. The characteristic relaxation time curves of each particular phase are analyzed by considering that they are constituted by a superposition of exponential decays with typical characteristic times: in a sense, a T2 spectroscopy. The analysis of the T2 dispersion profiles in both the uniaxial nematic calamitic and discotic phases indicates that our results can be interpreted in terms of the model of intrinsically biaxial micelles in all the nematic phases.
Rodriguez
C R
CR
Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba, Ciudad Universitária, X5016LAE Córdoba, Argentina.
Pusiol
D J
DJ
Figueiredo Neto
A M
AM
Martin
C A
CA