Molecular dynamics simulations of α- to β-poly (vinylidene fluoride) phase change by stretching and poling
2012 (English)In: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 53, no 14, p. 2927-2934Article in journal (Refereed) Published
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Abstract [en]
The mechanism of inducing a phase change from α-poly(vinylidene fluoride) (α-PVDF) to β-PVDF is addressed using molecular dynamics simulations based on a molecular mechanics force field. The effect of applying a strain to the α-PVDF crystal along the axis of the molecules is investigated, as well as poling the crystal before or after stretching. Rather large (at least 1010 V/m) electric fields that are perpendicular to the axis of the PVDF molecules are required to induce α- to β-PVDF phase change when no strain is applied to the α-PVDF crystal. However, at a strain of 1.0475 (i.e., when the crystal is stretched by 4.75%) α-PVDF changes to a β-PVDF like structure, where the β-PVDF molecules orientate anti-parallel relative to each other. Transformation of the anti-parallel β-PVDF to β-PVDF can be induced by poling (even at the lowest electric field of 105 V/m studied here) or by thermal annealing.
Place, publisher, year, edition, pages
Elsevier Ltd , 2012. Vol. 53, no 14, p. 2927-2934
Keywords [en]
poly (vinylidene fluoride), piezoelectric, computer simulations, Resursåtervinning
National Category
Materials Chemistry
Identifiers
URN: urn:nbn:se:hb:diva-1385Local ID: 2320/11638OAI: oai:DiVA.org:hb-1385DiVA, id: diva2:869409
2015-11-132015-11-132017-11-16Bibliographically approved