Despite the very common use of High Field Nuclear Magnetic Resonance (7 – 37 T), Low
Field Nuclear Magnetic Resonance (LF-NMR; 0.37 – 2.4 T), typically applied in food science
for the characterisation of edible fluids and solids, is much less common. However, the
works of Brownstein and Tarr [1], Mitra et al. [2], Chui et al. [3] and Scherer [4] clearly
demonstrated that the use of LF-NMR can be profitably extended to the study the microand
nano structure of polymeric systems such as gels [5] and scaffolds [6]. In addition, also
biological tissues such as bones [7] and sputum of patients affectd by cronic pulmonary
diseases such as cystic fibrosis paptients (CF) [8], can be characterized by LF-NMR.
Whatever the system considered, the leading principle allowing the LF-NMR
characterization relies on the effect of solid surfaces (polymeric chains, bones and so on)
on the relaxation process of water hydrogens subjected to a sudden variation of an
external magnetic field. The higher the ratio between system solid surface and system
volume, the faster the hydrogens relaxation process. Based on this information, it is
possible to obtain interesting information on the three-dimensional architecture of gels
network (mesh size distribution) and pores size distribution of porous materials.
The focus of this presentation will be on the characterization of polymeric gels network,
on the determination of scaffold pores size distribution and on the use of LF-NMR to
monitor CF patients.
