Probing subglass relaxation in polymers via a geometric representation of probabilities, observables, and relaxation modes for discrete stochastic systems

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Probing subglass relaxation in polymers via a geometric representation of probabilities, observables, and relaxation modes for discrete stochastic systems (EN)

Theodorou, DN (EN)
Boulougouris, GC (EN)

journalArticle (EN)

2014-03-01T01:31:42Z
2009 (EN)


The dynamics of many physical, chemical, and biological systems can be reduced to a succession of infrequent transitions in a network of discrete states representing low energy regions in configuration space. This enables accessing long-time dynamics and predicting macroscopic properties. Here we develop a new, perfectly general statistical mechanical/geometric formulation that expresses both state probabilities and all observables in the same Euclidean space, spanned by the eigenvectors of the symmetrized time evolution operator. Our formalism leads to simple expressions for nonequilibrium and equilibrium ensemble averages, variances, and time correlation functions of any observable and allows a rigorous decomposition of the dynamics into relaxation modes. Applying it to subglass segmental relaxation in atactic polystyrene up to times on the order of 10 μs, we probe the molecular mechanism of the γ and δ processes and unequivocally identify the δ process with rotation of a single phenyl group around its stem. © 2009 American Institute of Physics. (EN)

Physics, Atomic, Molecular & Chemical (EN)

polymer (EN)
heat (EN)
State probabilities (EN)
Atactic polystyrenes (EN)
Subglass relaxations (EN)
Long-time dynamics (EN)
Geometric representations (EN)
Segmental relaxations (EN)
Time correlation functions (EN)
Simple expressions (EN)
eigenvalues and eigenfunctions (EN)
Prostaglandins, Synthetic (EN)
Euclidean spaces (EN)
Stochastic Processes (EN)
Dynamics (EN)
Space probes (EN)
Polystyrenes (EN)
Discrete state (EN)
Molecular mechanisms (EN)
Ensemble averages (EN)
9 alpha,11 alpha,15 alpha-trihydroxy-16-phenoxy-17,18,19,20-tetranorprosta-4,5,13-trienoic acid (EN)
Eigenvectors (EN)
polymers (EN)
stochastic processes (EN)
Polymers (EN)
chemistry (EN)
Monte Carlo method (EN)
Phenyl groups (EN)
probability (EN)
Low energy regions (EN)
Macroscopic properties (EN)
Discrete stochastic systems (EN)
Time evolution operators (EN)
Probability (EN)
Hot Temperature (EN)
article (EN)
Relaxation modes (EN)
Configuration spaces (EN)
free energy (EN)
Stochastic systems (EN)
Biological systems (EN)
9 alpha,11 alpha,15 alpha trihydroxy 16 phenoxy 17,18,19,20 tetranorprosta 4,5,13 trienoic acid (EN)
Monte Carlo Method (EN)
Non equilibriums (EN)
prostaglandin derivative (EN)
statistics (EN)

Journal of Chemical Physics (EN)

Αγγλική γλώσσα

AMER INST PHYSICS (EN)




*Η εύρυθμη και αδιάλειπτη λειτουργία των διαδικτυακών διευθύνσεων των συλλογών (ψηφιακό αρχείο, καρτέλα τεκμηρίου στο αποθετήριο) είναι αποκλειστική ευθύνη των αντίστοιχων Φορέων περιεχομένου.