Molecular dynamics simulation of crystalline poly(ethylene oxide)
1994; American Institute of Physics; Volume: 101; Issue: 11 Linguagem: Inglês
10.1063/1.467995
ISSN1520-9032
AutoresSylvie Neyertz, David Brown, John O. Thomas,
Tópico(s)Ionic liquids properties and applications
ResumoMolecular dynamics (MD) simulation holds great promise as a source of otherwise elusive information concerning ionic conduction mechanisms occurring in the amorphous phases of polymer electrolytes. However, most polymer/salt complexes have a multiphase character at temperatures of interest. Insights into crystalline phases may thus prove meaningful in the subsequent design of strategies to decrease the degree of crystallinity in these systems. We report here the full details of a molecular dynamics model (‘‘md’’ model) for the crystalline phase of the widely used host-polymer poly(ethylene oxide) (PEO). Force-field and computational parameters are optimized to give realistic behavior for crystalline PEO. Analyses of the structure and dynamics obtained from the MD simulations performed at 300 K include mean-square displacements, x-ray powder diffractograms, distributions of bond and torsion angles, and radial distribution functions. These are compared with experimental data, the static x-ray determined PEO structure and that obtained using a ‘‘tethered’’ model, in which the atoms are attached by springs to their initial crystalline positions, and allowed to move according to their experimental mean-square displacements. Agreement is good, but the reliability of the x-ray refined positions is questioned.
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