Spatio-temporal anomalous diffusion in heterogeneous media by nuclear magnetic resonance.
J Chem Phys
; 135(3): 034504, 2011 Jul 21.
Article
em En
| MEDLINE
| ID: mdl-21787010
ABSTRACT
In this paper, we describe nuclear magnetic resonance measurements of water diffusion in highly confined and heterogeneous colloidal systems using an anomalous diffusion model. For the first time, temporal and spatial fractional exponents, α and µ, introduced within the framework of continuous time random walk, are simultaneously measured by pulsed gradient spin-echo NMR technique in samples of micro-beads dispersed in aqueous solution. In order to mimic media with low and high level of disorder, mono-dispersed and poly-dispersed samples are used. We find that the exponent α depends on the disorder degree of the system. Conversely, the exponent µ depends on both bead sizes and magnetic susceptibility differences within samples. The new procedure proposed here may be a useful tool to probe porous materials and microstructural features of biological tissue.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Espectroscopia de Ressonância Magnética
Idioma:
En
Revista:
J Chem Phys
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Itália