Hyperpolarization, NMR

Nossov, A.V. Soldatov, D.V. Ripmeester, J.A. In situ switching of sorbent functionality as monitored with hyperpolarized NMR spectroscopy. J. Am. Chem. 32. 

Chen and Hilty proposed a variant of the hyperpolarized NMR spectroscopy allowing for obtaining 2D correlations, e.g. between and... 

Hyperpolarized 129Xe NMR Spectroscopy, MRI and Dynamic NMR Microscopy for the In Situ Monitoring of Gas Dynamics in Opaque Media Including Combustion Processes... 

Fig. 5.3.2 (A) NMR spectrum of hyperpolar- abundance of approximately 25% of the, 29Xe ized 129Xe from a sample that contains bulk gas isotope. (B) 2D slice of 3D chemical shift phase (0.3 ppm) and xenon occluded within selective MRI of the bulk gas phase. (C-E) 2D aerogel fragments (25 ppm). The gas mixture slices of 3D chemical shift selective MRI of the used for the experiment contained 100 kPa of 25 ppm region for various recycle times T.

Fig. 5.3.3 (A) NMR spectrum of hyperpolarized 129Xe in NaX zeolites. (B) 2D slice in the flow direction of a 3D chemical shift selective MRI of gas in the zeolite pellets. (C) 2D slice perpendicular to the flow direction of the same 3D chemical shift selective MRI as in (A). Adapted from Ref. [14].

Moudrakovski, I.L. Sanchez, A.A. Ratcliffe, C.I. Ripmeester, J.A. (2001). Nucleation and Growth of Hydrates on Ice Surfaces New Insights from 129Xe NMR Experiments with Hyperpolarized Xenon. J. Phys. Chem. B, 105, 12338-12347. 

A number of recent developments in 129Xe NMR spectroscopy are presented with direct applications to the study of mesopore space in solids. This includes the establishment of a relationship between pore size and chemical shifts for a number of controlled pore glasses and the exploration of hyperpolarized (HP) xenon for a number of NMR and microimaging applications to porous solids. With HP xenon, the increase in experimental sensitivity is remarkable. Experiments illustrated include the rapid characterization of the void space in porous solids, including the in-situ study of processes such as diffusion and dehydration, and imaging with chemical shift resolution. 

Increasing the NMR Signal with Hyperpolarization. A very promising avenue for increasing sensitivity in NMR and MRI is to increase the signal from the molecules being detected. The low radio-frequency energy used for NMR means that... 

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