Nuclear magnetic resonance solid-state

High salt concentrations have been shown to retain only the narrow component, while the more dilute PEO-salt samples contain both the narrow and broad components. In dilute PEOrsalt electrolytes, three regions have been shown to exist (1) pure crystalline PEO, (2) amorphous PEO, (3) amorphous PEO-Li salt complex, and (4) crystalline PEO-Ii salt complex.  

Variable temperature study with a subsequent line shape analysis enables a clear insight of the temperature-dependent dynamics of the system, where the glass transition temperature (Tg) of the amorphous phase, melting point or a crystallization onset of a present crystalline phase, or any other changes caused by altered dynamics of the involved species can be assessed. This was recognized by early investigations of polymer electrolytes and will be discussed in greater detail later. 

Linewidth changes dependent on salt amount were examined by Liao et (see Fig. 7.3), and the line shape was also examined on heating and cooling, as shown in Fig. 7.4. From these graphs it is possible to conclude that spectral lines are narrow in the liquid crystal phase, while they broaden 

3 Li and F NMR linewidths t ersus temperature for C1805 LiBp4 (1 )d second heating cycle data, denotes the side chain melting temperature. Filled symbols are for Li and open symbols are for F. (a) , O, x= 0.7, salt-deficient sample (b) M, x= 1, equimolar sample (c) A, A, x= 1.3 excess salt sample (d) selected Li NMR signals from (b). From Y-P. Liao, D. C. Apperley, J. Liu, Y. Zheng, 

sets of samples are studied where one parameter, concentration or relative amount of one of the components, or one component itself, is varied. The observed changes in dynamics and morphology caused by the altered composition of the sample, such as relative amount of crystallinity, altered coordination of the involved species, or different degree of ionpairing, are of paramount importance in the quest for an optimized electrolyte system. 

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In the following, some examples of applications of Fourier transform infrared (FTIR) Spectroscopy and of solid-state nuclear magnetic resonance (NMR) to the study of polymorphism in polymers are described. 

A solid-state nuclear magnetic resonance (NMR) experiment was carried out in 4 mm double bearing rotor made from Zr02 on a Bruker DSX 200 MHz spectrometer with resonance frequency at 75.468 MHz. The pulse length was 3.5 ps and the contact time of IH-13C CP was 2-5 ms. 

Lazo ND, Meine JG, Downing DT (1995) Lipids are covalently attached to rigid corneocyte protein envelope existing predominantly as beta-sheets a solid state nuclear magnetic resonance study. J Invest Dermatol 105 296-300... 

Solid-state nuclear magnetic resonance (NMR) on nuclei has been used for... 

F. Volke, A. Pampel 1995, (Membrane hydration and structure on a subnanometer scale as seen by high resolution solid state nuclear magnetic resonance POPC and P0PC/C12E04 model membranes), Biophys.J. 68, 1960-1965. 

Solid-state nuclear magnetic resonance spectroscopy (SSNMR) [13]... 

Because of the grandiose scale of the apparatus involved, SANS facilities are few in number worldwide access to them is limited and expensive. We have attempted to devise an experiment which employs solid state nuclear magnetic resonance to examine some aspects of affine deformation. 

The two structurally similar polymorphs of (R,S)-ethambutol dihydrochloride have been shown to bear an enantiotropic relationship, and can reversibly interconvert in a single crystal transformation mode [27]. It was reported that despite the identity in space group type and similarity in unit cell constants, the two forms could be distinguished on the basis of their X-ray powder diffraction and solid-state nuclear magnetic resonance properties. Interestingly, while the (polymorphic forms, the (R,S)-diastereomer was only obtained in two different polymorphs. 

Crosslinked polymer networks formed from multifunctional acrylates are completely insoluble. Consequently, solid-state nuclear magnetic resonance (NMR) spectroscopy becomes an attractive method to determine the degree of crosslinking of such polymers (1-4). Solid-state NMR spectroscopy has been used to study the homopolymerization kinetics of various diacrylates and to distinguish between constrained and unconstrained, or unreacted double bonds in polymers (5,6). Solid-state NMR techniques can also be used to determine the domain sizes of different polymer phases and to determine the presence of microgels within a poly multiacrylate sample (7). The results of solid-state NMR experiments have also been correlated to dynamic mechanical analysis measurements of the glass transition (1,8,9) of various polydiacrylates. 

Antzutkin, O. N., Leapman, R. D., Balbach, J. J., and Tycko, R. (2002). Supramolecular structural constraints on Alzheimer s beta-amyloid fibrils from electron microscopy and solid-state nuclear magnetic resonance. Biochemistry 41, 15436-15450. 

Direct analysis 7.1 XRD, XRF, infrared spectroscopy (NIR and MIR), solid-state nuclear magnetic resonance (NMR), advanced spectroscopy using synchrotron radiation, neutron activation, fluorescence, and visible and electron microscopy... 

Wilson et al. [2] carried out a compositional and solid state nuclear magnetic resonance (NMR) spectroscopic study of humic and fulvic acid and fractions present in soil organic matter. 

A solution-state and solid-state nuclear magnetic resonance study of the complex and its separate components in both their neutral and ionized (TMP hydrochloride and SMZ sodium salt) forms was undertaken in order to elucidate the TMP-SMZ interactions. Inspection of the data for the complex in the solid state shows that the 13C chemical shifts are consistent with the ionic structure proposed by Nakai and coworkers105 (14). Stabilization of the complex is achieved by the resulting ionic interaction and by the formation of two intermolecular hydrogen bonds. 

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