Anomalous component dynamics

Anomalous component dynamics in blends and mixtures have been observed which cannot be explained by the models of Fischer et al., Kumar et al., and Lodge and McLeish [329]. A recent example is the anomalous dynamics of d4PEO found in the d4PEO/PMMA polymer blends [336], While this anomaly cannot be understood by the other models, it has an immediate explanation from the CM [337],... 

The component dynamics in polymer-diluent mixtures discussed in the previous section are similar to those of polymer blends, such as the appearance of two different TgS (Fig. 2.15). Thus, a theory of component dynamics of polymer blends is robust only if it is also applicable to polymer-diluent mixtures and can explain the anomalous component dynamics found therein [98-101]. If it can be extended... 

Force field calculations often truncate the non bonded potential energy of a molecular system at some finite distance. Truncation (nonbonded cutoff) saves computing resources. Also, periodic boxes and boundary conditions require it. However, this approximation is too crude for some calculations. For example, a molecular dynamic simulation with an abruptly truncated potential produces anomalous and nonphysical behavior. One symptom is that the solute (for example, a protein) cools and the solvent (water) heats rapidly. The temperatures of system components then slowly converge until the system appears to be in equilibrium, but it is not. 

Liquid polymorphism in one-component fluids is an example of so-called anomalous phase behavior. This term is used to emphasized the difference with respect to the normal behavior characterizing prototypical (i.e., argon like) simple liquids. Anomalous behavior includes, in addition to polymorphism in the liquid and solid phases, reentrant melting, that is, melting by compression at constant temperature, and a number of other thermodynamic, dynamic, and structural anomalies, as, for example, the density anomaly (a decrease in density upon cooling), the diffusion anomaly (an increase of diffusivity upon pressurizing), and the structural anomaly (a decrease of structural order for increasing pressure). 

In terms of the real permittivity, the anomalous reduction in this parameter on addition of a low volume fractiOTi (<5 %) of a high permittivity nanofiller can be interpreted in terms of local interactions between the nanofiller and the epoxy serving to immobilise a region of the matrix immediately adjacent to the nanoparticle surface. In such circumstances, the presence of a third component (i.e. an interphase region where the nanoparticles serve to modify the structure and/or dynamics of the matrix) is commOTily invoked, such that the Lichtenecker-Rother equation given above should be rewritten. 

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