Structure and vibrational frequency determination for α-poly(vinylidene fluoride) using density-functional theory

Ramer, Nicholas J.; Marrone, Theresa; Stiso, Kimberly A.

doi:10.1016/j.polymer.2006.08.012

Cited by 57 publications

(40 citation statements)

References 55 publications

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“…This has attracted the attention of researchers for many years and a large number of experimental and theoretical studies on PVDF, including its crystal phases, have been made [6][7][8][9][10][11]. PVDF forms at least four crystalline phases, including the α-and β-phases.…”

Section: Introductionmentioning

confidence: 99%

Simulation of α- and β-PVDF melting mechanisms

Erdtman

Satyanarayana

Bolton

2012

Polymer

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Molecular dynamics (MD) simulations have been used to study the melting of α-and β-poly (vinylidene fluoride) (α-and β-PVDF). It is seen that melting at the ends of the polymer chains precedes melting of the bulk crystal structure. Melting of α-PVDF initially occurs via transitions between the two gauche dihedral angles (G ↔ G') followed by transitions between trans and gauche dihedral angles (T ↔ G/G'). Melting of β-PVDF initially occurs via T → G/G' transitions and via transitions of complete β-(TTTT) to α-(TGTG') quartet. The melting point of β-PVDF is higher than that of α-PVDF, and the simulated melting points of both phases depend on the length of the polymer chains used in the simulations. Since melting starts at the chain ends, it is important to include these in the simulations, and simulations of infinitely long chains yield melting points far larger than the experimental values (at least for periodic cells of the size used in this work), especially for β-PVDF. The simulated heats of fusion are in agreement with available experimental data.

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Section: Introductionmentioning

confidence: 99%

Simulation of α- and β-PVDF melting mechanisms

Erdtman

Satyanarayana

Bolton

2012

Polymer

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“…Recent examples of such a hybrid approach to investigations of the ferroelectric-polymer systems include predictive evaluation of the properties of PVDF, 26,27 VDF copolymers, 28 and PVDF analogs, 27,29 as well as the computation of their vibrational spectra. [30][31][32] In this paper, using DFT techniques, we evaluate the stability of the highly symmetric Amm2 ferroelectric ␤-PVDF phase. We find that its dynamically stable configuration includes a slight distortion away from this symmetry in a form of an ordered dihedral-tilt angle staggering along the polymer backbone.…”

Section: Introductionmentioning

confidence: 99%

Vibrational properties of ferroelectricβ-vinylidene fluoride polymers and oligomers

et al. 2010

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We utilize a plane-wave density-functional theory approach to investigate the vibrational properties of the all-trans ferroelectric phase of poly͑vinylidene fluoride͒ ͑␤-PVDF͒ showing that its stable state corresponds to the Ama2 structure with ordered dihedral tilting of the VDF monomers along the polymer chains. We then combine our theoretical analysis with IR spectroscopy to examine vibrations in oligomer crystals that are structurally related to the ␤-PVDF phase. We demonstrate that these materials-which can be grown in a highly crystalline form-exhibit IR activity similar to that of ␤-PVDF, making them an attractive choice for the studies of electroactive phenomena and phase transitions in polymer ferroelectrics.

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“…The order of G(δ) and of F(δ) is equal to N (the number of internal coordinates in a chemical repeat unit). A Fourier transform on the system of internal displacement coordinate is defined, in order to give a set of internal symmetry coordinates (18) The elements of the G(δ) and F(δ) matrices are then…”

Section: Vibrational Dynamics Of Polymersmentioning

confidence: 99%

“…This has been done in a variety of symmetry groups [4][5][6][7][8][9][10][11][12][13][14][15][16]. Strong supporting evidence of the spectral parameters (constants of IR and Raman) is obtained from quantum chemical [Hartree-Fock (HF), post-HF, and density functional theory (DFT)] [17][18][19][20] and molecular dynamical (MD) approaches. They have the additional advantage of including interchain interaction and anharmonic effects.…”

Section: Introductionmentioning

confidence: 99%

Conformational symmetry and vibrational dynamics of polymers

Tandon

Kumar

Gupta

et al. 2009

Pure and Applied Chemistry

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Polymers are an important class of materials, and their conformation dictates their dynamical, thermodynamical, and hydrodynamical behavior. Several spectroscopic and other techniques have been employed to characterize their conformation. However, little use has been made of group-theoretical techniques except in the classification of symmetry species. In the present review, an attempt has been made to correlate normal modes and their dispersion profiles with the conformation of the polymeric systems. This has been attempted in the case of 2-, 3-, 4-fold and α-helical polymers.

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Structure and vibrational frequency determination for α-poly(vinylidene fluoride) using density-functional theory

Cited by 57 publications

References 55 publications

Simulation of α- and β-PVDF melting mechanisms

Simulation of α- and β-PVDF melting mechanisms

Vibrational properties of ferroelectricβ-vinylidene fluoride polymers and oligomers

Conformational symmetry and vibrational dynamics of polymers

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