Spatio-temporal ordinary and anomalous diffusion in heterogeneous and organic media by NMR

In this talk we give an overview of the self-diffusion properties of water molecules in eterogeneous materials and of its study by novel NMR methods. We study both the cases of human brain tissues in vivo and of artificial complex porous media obtained by mono and polydisperse sphere packing of micro-beads dispersed in water. In particular for the second case, the diffusion phase diagram in highly confined colloidal systems, predicted by Continuous Time Random Walk (CTRW), is experimentally obtained. Temporal and spatial fractional exponents introduced within the framework of CTRW, are simultaneously measured by Pulse Field Gradient Nuclear Magnetic Resonance technique in samples of micro-beads dispersed in water.