Orientational disorder

The thermotropic mesophases are well enough understood to propose a subdivision into six types. Depending on the type of disorder, they are called liquid crystals, plastic crystals or condis crystals (positional and if applicable conformational disorder, orientational disorder, and conformational disorder, respectively). For the corresponding glasses, which represent the frozen-in mesophases, the names LC-, PC-, and CD-glasses are proposed (Fig. 2). For macromolecules not only equilibrium... 

Adsorbates such as HQ which are capable of more than one surface orientation can undergo a transition from uniformly oriented adsorption to mixed or disordered orientation [60] as the temperature rises about 45°C, as shown in Fig. 29. 

In crystalline materials, with the alkane chains tightly packed and in an all-//cum conformation, the asymmetric stretch of the methylene groups va(CH2) shows at 2918 cm-1, whereas in liquid state, with disordered orientation of alkane chains and high concentration of gauche interactions, the position of this peak is shifted towards higher frequencies (2921-2924 cm-1). 

Benzotrisfuroxan forms complexes with various organic molecules two of these, and the uncomplexed molecule, have been studied by X-ray methods. The complex with the thiophene-cyclophane (19) gave structural parameters for both molecules, but the copper oxinate complex appeared to possess a disordered orientation of the trifuroxan. The shortness of the exocyclic N—0 bond is remarkable, " as has been noted also in simple furoxans. ... 

The overall entro of fusion AS, of a crystal can be approximately separated into the three contributions, arising from positional disordering, orientational disordering, and conformational disordering, A5., so that... 

The direct and reverse problems of the spectroturbidimetry of ordered disperse systems are discussed by Khlebtsov et al. (1994), Shchyogolev et al. (1994). Recording the attenuation spectra of disordered, oriented, and relaxing disperse systems, one can obtain... 

Crystallites Total weight fraction Size Disorder Orientation Area under the crystaUine peak relative to the scattered intensity Width of the Bragg peaks Increase in the widths of the peak with scattering angle Azimuthal spread of the intensity in the crystalline reflections... 

Two types of carbon can be used as active anode materials [94, 95] soft carbon, also called graphitized carbon where crystallites are oriented almost in the same direction, and hard carbon where crystallites have disordered orientations. Both are used in lithium-ion batteries, but they do not have the same properties. 

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