Carbon-13 nuclear magnetic relaxation in supercooled liquid and glassy maltose
- 1 January 1999
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Physical Chemistry Chemical Physics
- Vol. 1 (8) , 1927-1931
- https://doi.org/10.1039/a808667b
Abstract
13 C longitudinal relaxation rates (T1 -1) in highly viscous liquid and solid amorphous maltose, its mixtures with water and methanol, and also crystalline maltose monohydrate, have been measured as a function of temperature, above and below the calorimetric glass transition temperatures of the amorphous materials. From the results it is concluded that, at temperatures up to 60°C below the glass transition temperature, the carbon atoms in the exocyclic hydroxymethyl groups of maltose are more mobile than the endocyclic carbon atoms. A few percent of water is sufficient to considerably enhance amorphous maltose mobility. At temperatures close to the glass transition methanol in amorphous maltose–methanol mixtures retains a high degree of rotational mobility which is decoupled from the bulk viscosity.Keywords
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