Inhomogeneity, dynamic

Mihailovic D, Kabanov VV (2005) Dynamic Inhomogeneity, Pairing and Superconductivity in Cuprates 114 331-365... 

To this end, we review the physics of high temperature fused salts and draw on observations made in these systems to understand the microscopic structure of ionic liquids. We also review some physics of glass-forming liquids, focusing on concepts necessary to understand structural and dynamic inhomogeneity in ILs. We provide a broad review of attempts to characterize ILs empirically, and discuss those results with reference to simulation and theoretical studies. The overall objective of this study is to develop a conceptual toolbox that can be used to interpret experimental results in ILs and help identify useful new questions for the field. To this end, we present a series of principles describing the nature of solvation in ionic liquids at the conclusion of this chapter. 

The existence of dynamical inhomogeneity also explains certain measurements for self-diffusion in ILs that have previously been attributed to ion pairing. Watanabe and co-workers [165-170] conducted studies on a range of ILs, comparing the molar conductivities calculated via PGSE-NMR (nuclear magnetic resonance) measurement against those obtained via electrochemical... 

As discussed below, ionic liquids often behave comparably to conventional polar organic solvents [6, 8, 10]. But the physics underlying solvation are entirely different. As noted above, ILs are characterized by considerable structural and dynamic inhomogeneity, and even simple concepts, such as the dipole moment, cannot be productively applied. We are therefore in the unusual position of needing to explain how an exotic microscopic environment produces conventional macroscopic behavior. To this end, we will review empirical characterizations of the ionic liquid environment, and then turn our attention to the underlying physics of solute-solvent interactions. 

In addition to conventional static and MAS measurements on molybdenum oxide catalysts, static-echo techniques have also been applied [125, 127, 129]. Spin-echo spikelet experiments allow the presence of dynamically active surface-interactive molybdenum oxide species to be resolved. Figure 5.20 compares the spikelet-echo spectra of MoO, /Al203 of different loadings before and after calcination. The existence of the broad resonance on which the observed spikelets are superimposed indicates that the surface is dynamically inhomogeneous. As discussed in Section 5.2.22 the basis of the spikelet-echo experiment is that surface species with high mobility will have short spin-spin relaxation times in comparison with species immobilized on the surface. The spikelet-echo experiment is designed to distinguish species on the basis of their T2 values. 

Are some or all of these materials made of submicroscopic domains The structural inhomogeneity is apparently parallel to dynamic inhomogeneity molecular rotation and translation may occur significantly faster in one part of the sample than in another part a few nanometers away . Cicerone, M. T. Ediger, M. D. Enhanced translation of probe molecules in supercooled o-terphenyl signature of spatially heterogeneous dynamics /. Chem. Phys. 1996, 104, 7210-7218. 

Static and Dynamic Inhomogeneities in New Hierarchical Liquid Crystal Structures Caused by Frustration... 

Detailed simulations [416] indicate the importance of inhomogeneity effects for the dispersion (cf. static distribution of thresholds and time constants, see also Section 7.3.6). This is of special importance in the case of amorphous systems. While the jump relaxation model explicitly addresses dynamic inhomogeneity effects in the sense of Fig. 6.34, possible static inhomogeneities have to be included in the eflFective defect potential and the relation between jump and relaxation rate. A competent recent review is given in Ref. [418]. 

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