Variable Field Relaxometry
NMRD (Nuclear Magnetic Relaxation Dispersion), also called Field Cycling NMR or variable field relaxometry is growing in use for the characterisation of materials. NMRD provides a wide spectrum of correlation times and dynamic models much more complex than what might appear from relaxation studies carried out at high fields and fixed frequencies.
NMRD is used for characterisation of new MRI contrast agents optimised for new higher-field MRI systems. NMRD is also used in materials science for the characterisation of polymers, solid BSA, novel nanostructured materials, as well as foods and discriminates between fresh and used oils.
Our application development partner, Stelar, based in Italy provides the electronics and applications software. Highly customised systems for integration with industrial production lines can also be provided in associatiion with Stelar.
Other uses of NMRD include:
Liquid crystals and lipid bilayers
Field-cycling relaxometry in studies of bulk liquid crystals is attractive due to the strong relaxation dispersion that characterises these materials and the strong differences in the dispersions corresponding to different mesophases. A second good reason is the remarkably good sensitivity to spatial conﬁnements, even at temperatures corresponding to the bulk isotropic state.
Porous media and adsorption phenomena at liquid/solid interfaces
Relaxometry as well as diffusometry measure averages of the adsorbed and free phases. In diffusion measurements the normally large fraction of molecules in the bulk-like phase tends to dominate, whereas relaxometry is governed by the often quite small fraction of molecules that are initially as well as ﬁnally adsorbed.
Field cycling relaxometry is particularly useful to elucidate features of different molecular dynamics processes. The straightforward connection between theoretical principles and experimental data characteristic of this method has been shown to be of great importance in this context.