Molecular-dynamics simulation of structural and conformational properties of poly(propylene oxide)

Ahlström, Peter; Borodin, Oleg; Wahnström, Göran; Wensink, Erik J. W.; Carlsson, Patrik; Smith, Grant D.

doi:10.1063/1.481700

Cited by 19 publications

(16 citation statements)

References 26 publications

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“…These values of the momentum transfer correspond to the respective position of the first maximum of the intermolecular oxygen-oxygen pair distribution functions. 44,45 In Fig. 1, we see that the incoherent intermediate scattering functions F s (q, t) for the oxygen atoms of PPO show a pronounced temperature dependence, in particular at low temperatures.…”

Section: A General Characterization Of the Structural Relaxationmentioning

confidence: 90%

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Conformational and Structural Relaxations of Poly(ethylene oxide) and Poly(propylene oxide) Melts: Molecular Dynamics Study of Spatial Heterogeneity, Cooperativity, and Correlated Forward–Backward Motion

Vogel

2008

Macromolecules

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Performing molecular dynamics simulations for all-atom models, we characterize the conformational and structural relaxations of poly(ethylene oxide) and poly(propylene oxide) melts. The temperature dependence of these relaxation processes deviates from an Arrhenius law for both polymers. We demonstrate that mode-coupling theory captures some aspects of the glassy slowdown, but it does not enable a complete explanation of the dynamical behavior. When the temperature is decreased, spatially heterogeneous and cooperative translational dynamics are found to become more important for the structural relaxation. Moreover, the transitions between the conformational states cease to obey Poisson statistics. In particular, we show that, at sufficiently low temperatures, correlated forward-backward motion is an important aspect of the conformational relaxation, leading to strongly nonexponential distributions for the waiting times of the dihedrals in the various conformational states.

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Section: A General Characterization Of the Structural Relaxationmentioning

confidence: 90%

“…It was demonstrated that these models enable a good reproduction of thermodynamic, structural, and dynamical aspects of PEO and PPO melts. 45,46,47 The MD simulations were performed using the GRO-MACS software package. 53 We applied periodic boundary conditions and a time step of 1 fs.…”

Section: Methodsmentioning

confidence: 99%

Conformational and Structural Relaxations of Poly(ethylene oxide) and Poly(propylene oxide) Melts: Molecular Dynamics Study of Spatial Heterogeneity, Cooperativity, and Correlated Forward–Backward Motion

Vogel

2008

Macromolecules

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“…All MD simulations were performed using the simulation package Gromacs (24). For further description of the simulation, see Reference (18).…”

Section: Molecular Dynamicsmentioning

confidence: 99%

“…Previously, reverse Monte Carlo (RMC) modeling was used to investigate the structure of PPO (16). Then, using the RMC model as a starting structure, the force field proposed in Reference (17) was successfully used in Reference (18) to describe the structure of PPO. The results compared even more favorably with the experimental structure factor when a quantum path integral approach was used (19).…”

Section: Introductionmentioning

confidence: 99%

The Segmental and Rotational Dynamics of PPO, Above the Glass‐Transition, Investigated by Neutron Scattering and Molecular Dynamics Simulations

et al. 2005

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AThe relaxation properties of poly(propylene oxide) at temperatures above the glass-transition temperature are studied by quasi-elastic neutron scattering and molecular dynamics (MD) simulations. The contributions to the dynamic structure factor from the segmental motion and the methyl group jump rotation are separated using a threefold jump-rotation model for the methyl side group motion, with a delta function for the distribution of relaxation times, and a stretched exponential function for the segmental motion.This simple model describes momentum transfer and time dependence of the data over a wide temperature range. The results show that with this separation, both neutron and MD data can be well described, and the analysis of both contributions is necessary in order to obtain reliable results for the segmental relaxation and rotational relaxation times at temperature above T g .

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“…Halley and coworkers have studied the structure of amorphous PEO using the Parrinello-Rahman method recently [21]. MD simulations have also been employed by Smith and coworkers to elucidate the structure and dynamics of poly(propylene oxide) melts [22], PEO-salt complexes [23] and aqueous PEO solutions [24], using a potential model derived from ab initio calculations [25].…”

Section: Introductionmentioning

confidence: 99%

Vibrational dynamics of solid poly(ethylene oxide)

Krishnan

Balasubramanian

2003

Phys. Rev. B

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Molecular dynamics (MD) simulations of crystalline poly(ethylene oxide) (PEO) have been carried out in order to study its vibrational properties. The vibrational density of states has been calculated using a normal mode analysis (NMA) and also through the velocity autocorrelation function of the atoms. Results agree well with experimental spectroscopic data. System size effects in the crystalline state, studied through a comparison between results for 16 unit cells and that for one unit cell has shown important differences in the features below 100 cm^-1. Effects of interchain interactions are examined by a comparison of the spectra in the condensed state to that obtained for an isolated oligomer of ethylene oxide. Calculations of the local character of the modes indicate the presence of collective excitations for frequencies lower than 100 cm^-1, in which around 8 to 12 successive atoms of the polymer backbone participate. The backbone twisting of helical chains about their long axes is dominant in these low frequency modes.Comment: 19 pages, 7 figures (Phys.Rev.B submitted on 28.11.2002) Revised versio

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Molecular-dynamics simulation of structural and conformational properties of poly(propylene oxide)

Abstract: Articles you may be interested inMolecular dynamics simulation study of solvent effects on conformation and dynamics of polyethylene oxide and polypropylene oxide chains in water and in common organic solvents

Cited by 19 publications

References 26 publications

Conformational and Structural Relaxations of Poly(ethylene oxide) and Poly(propylene oxide) Melts: Molecular Dynamics Study of Spatial Heterogeneity, Cooperativity, and Correlated Forward–Backward Motion

Conformational and Structural Relaxations of Poly(ethylene oxide) and Poly(propylene oxide) Melts: Molecular Dynamics Study of Spatial Heterogeneity, Cooperativity, and Correlated Forward–Backward Motion

The Segmental and Rotational Dynamics of PPO, Above the Glass‐Transition, Investigated by Neutron Scattering and Molecular Dynamics Simulations

Vibrational dynamics of solid poly(ethylene oxide)

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