Cellulose resonance spectroscopy

By using this technique acrylamide, acrylonitrile, and methyl acrylate were grafted onto cellulose [20]. In this case, oxidative depolymerization of cellulose also occurs and could yield short-lived intermediates [21]. They [21] reported an electron spin resonance spectroscopy study of the affects of different parameters on the rates of formation and decay of free radicals in microcrystalline cellulose and in purified fibrous cotton cellulose. From the results they obtained, they suggested that ceric ions form a chelate with the cellulose molecule, possibly, through the C2 and C3 hydroxyls of the anhy-droglucose unit. Transfer of electrons from the cellulose molecule to Ce(IV) would follow, leading to its reduction... 

The structural homogeneity of the various cellulose triacetate fractions obtained by fractional precipitation was established by both Infrared and nuclear magnetic resonance spectroscopy. 

P. S. Belton, S. F. Tanner, N. Cartier, and H. Chanzy, High-resolution sohd-state C nuclear magnetic resonance spectroscopy of tunicin, an animal cellulose. Macromolecules, 22 (1989) 1615-1617. 

Derham, M., Edge, M., WTUiams, D. A. R., WTUiamson, D. M. (1992). The Degradation of cellulose triacetate studied hy nuclear resonance spectroscopy and molecular modeling. In Postprints of Polymers in Conservation conference Manchester, 17-19 July 1991 (N.S. AUen, M. Edge and C.V. Horie, eds.) pp. 125-137 Royal Society of Chemistry. 

Infrared spectroscopy has been extensively used in both qualitative and quantitative pharmaceutical analysis [1-3], This technique is important for the evaluation of the raw materials used in production, the active ingredients and the excipients (the inert ingredients in a drug formulation, e.g. lactose powder, hydroxypropyl cellulose capsules, etc.). Although nuclear magnetic resonance spectroscopy and mass spectrometry are widely used in the pharmaceutical industry for the identification of drug substances, infrared spectroscopy can provide valuable additional structural information, such as the presence of certain functional groups. 

Belton P.S., Tanner S.F., Cartier N., and Chanzy H. 1989. High-resolution solid-state C nuclear magnetic resonance spectroscopy of tunicin, animal cellulose. Macromolecules 22 1615-1617. 

In our work CP/MAS C-NMR (Cross-Polarization Magic Angle Spurning Carbon-13 Nuclear Magnetic Resonance) spectroscopy togefiier wifii spectral fitting has been the method used for stud3dng interactions between cellulose I and hemicelluloses. A necessary prerequisite for this approach is a reliable interpretation of cellulose I spectra. 

Now that the range of likely shapes has been defined by experiments on related molecules and by energy calculations, we focus on the details of specific structures that have been observed for real, crystalline cellulose molecules, primarily by x-ray, neutron, and electron diffraction studies. A number of landmark concepts have been established with electron microscopy, as well. Infrared (IR), Raman, and nuclear magnetic resonance (NMR) spectroscopy have all also been important in the quest for understanding cellulose structure. Such data, while so far not able to provide complete definitive structures themselves, constitutes additional criteria that any proposed structure must be able to explain. In addition, unlike crystallography, the resolution of spectroscopic methods is not directly affected by the dimensions of the... 

Atalla RH and VanderHart DL (1999) The role of solid state C-13 NMR spectroscopy in studies of the nature of native celluloses. Solid State Nuclear Magnetic Resonance, 75(1) 1-19... 

Chemically modified celluloses have been analyzed by conventional wet methods and by various Instrumental methods designed to differentiate bulk and surface properties. Electron emission spectroscopy for chemical analyses (ESCA) used alone and In combination with radiofrequency cold plasmas yielded elemental analyses, oxidative states of the element, and distribution of the element. Techniques of electron paramagnetic resonance (EPR), chemiluminescence, reflectance infrared spectroscopy, electron microscopy, and energy dispersive X-ray analyses were also used to detect species on surfaces and to obtain depth profiles of a given reagent in chemically modified cottons. 

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