23NA NUCLEAR QUADRUPOLAR RELAXATION AS A PROBE OF THE MICROSTRUCTURE AND DYNAMICS OF AQUEOUS CLAY DISPERSIONS : AN APPLICATION TO LAPONITE GELS

摘要: 23Na relaxation studies of aqueous clay dispersions showed influence the order/disorder transition gels and quadrupolar neutralizing sodium counterions. Detection fast slow components transverse magnetization gives access to microstructural dynamical properties colloidal dispersions. Numerical simulations diffusion, using a simplified model dispersion, explain pathology rates by high sensitivity coupling orientational correlations charged interfaces. Frequency variation NQR confined counterions therefore appears as new tool for investigation spatial interfaces within disordered porous media.