Process induced electroactive beta-polymorph in PVDF: effect on dielectric and ferroelectric properties

Sharma, Maya and Madras, Giridhar and Bose, Suryasarathi (2014) Process induced electroactive beta-polymorph in PVDF: effect on dielectric and ferroelectric properties. In: PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 16 (28). pp. 14792-14799.

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Abstract

The effects of various processing conditions, like annealing, poling, mechanical rolling and their combinations, on the dielectric and ferroelectric properties of PVDF poly(vinylidene fluoride)] were systematically studied in this work. Further, the effect of processing sequence on the structure and properties was investigated. While all the processing conditions adopted here resulted in phase transformation of the alpha- to electroactive beta-polymorph in PVDF, the fraction of beta-phase developed was observed to be strongly contingent on the adopted process. The transformation of alpha- to electroactive beta-polymorph was determined by X-ray diffraction and FTIR. The neat PVDF showed only beta-phase, whereas mechanically rolled samples exhibited the highest ca. 85% beta-phase in PVDF. Both the permittivity and the loss tangent decreased in the samples which had undergone different processing conditions. The polarization-electric field (P-E) loops for all the samples were evaluated. Interestingly, the energy density, estimated from the electrical displacement-electric field (D-E) loops, was observed to be highest for the poled samples which were initially rolled. The results indicate that various processing conditions can influence the dielectric and the ferroelectric properties differently.

Item Type:	Journal Article
Publication:	PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Publisher:	ROYAL SOC CHEMISTRY
Additional Information:	Copy right for this article belongs to the ROYAL SOC CHEMISTRY, THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	20 Aug 2014 09:38
Last Modified:	20 Aug 2014 09:38
URI:	http://eprints.iisc.ac.in/id/eprint/49646

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