Nuclear magnetic resonance solid mobility measurement

The objectives of this review are to discuss the fundamental and more recently discovered properties of water alone and to critically examine the system properties and measurement methods used to measure the mobility of water and solids in foods—specifically water activity, nuclear magnetic resonance (NMR), and the glass transition. 

Moisture was known to increase the mobility of the surface groups of protein as measured by solid-state nuclear magnetic resonance spectroscopy The distribution of water between the protein and the excipients in a freeze-dried powder depends on the crystalline or amorphous nature of the excipients. For example, if a protein is formulated with an amorphous excipient and stored in a sealed container, water would distribute according to the water affinity of the protein and excipients.When the amorphous excipient crystallizes (e.g., because of elevated temperatures), it will expel its sorbed water, which may cause stability problems in the protein. ... 

In 1956 Thompson and Woods reported that dynamic experiments in extension indicated that orientation increased the temperature of the p transition, about 80°C, for oriented crystalline fibres, and reduced the drop in modulus occurring at higher temperatures. Subsequently nuclear magnetic resonance was used to demonstrate that orientation reduced molecular mobility above the glass transition temperature. Measurements of dynamic extensional and torsional moduli of hot stretched filaments and films were reported in 1963 by Pinnock and Ward, who found that the relations between measured compliances below the glass transition temperature were consistent with the deformation of an incompressible elastic solid. 

Nuclear magnetic resonance is sensitive to molecular mobility and local magnetic fields. Motion is modified in liquids contained in confined geometry. Local magnetic field variation results from susceptibility effects at interfaces. Both phenomena are observed for liquids contained in porous solids. This paper critically examines these effects and their use in characterisation of porous materials. The principles are illustrated with porous silicas and preliminary results are given of diffusion measurements on n-butane in silica as a function of temperature and pore geometry. 

Most of the polymer electrolytes that have been studied are solid solutions of salts in polymers. There is a possibility that both the cation and anion are mobile in such electrolytes. The ionic transport number in polymer electrolytes is a very important parameter in terms of the conduction mechanism of ions in polymers and of their practical application. Cationic transport numbers have been measured in the polymer electrolytes, especially in those of PEO using various methods, including nuclear magnetic resonance (NMR) [49,50], complex impedance measurements [51,52], tracer diffusion... 

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