400 MHz NMR-Spectrometer for 9,4 T Magnet

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Diffusion is a ubiquitous process in nature and pulsed field gradient NMR is a powerful experimental technique to probe diffusion processes on the most relevant length scale in the micrometer range. In heterogeneous, porous materials - besides complex structure - transport relationships and different types of phase transitions occurring in the pore spaces further complicate the transport processes. Their understanding may lay down a new approach for obtaining deeper insight into various equilibrium and non-equilibrium processes occurring in the pore spaces and for structural characterization of complex pore networks, including hierarchical pore systems. This challenging task will be addressed by complementing the NMR spectrometer (i) by a home-built pulsed field gradient unit that allows for probing diffusion processes down to hundred nanometers with the option of spectral selectivity by using magic angle spinning diffusion NMR and (ii) by in-situ pressure and temperature variation equipment with the option to maintain their gradients across the sample. In the latter case, the NMR microimaging (micro-MRI) capability will be used for spatially-resolved measurements of non-equilibrium and steady-state processes. Complementary “dynamic” imaging, where the diffusion patterns probed are used for elucidating the local structural properties of ordered and disordered pore systems, and high-resolution microimaging studies will be used to better understand the relationship between microstructure and MRI contrast maps.