Critical insights into the effect of shear on in situ reduction of graphene oxide in PVDF: assessing by rheo-dielectric measurements

Sharma, Maya and Madras, Giridhar and Bose, Suryasarathi (2016) Critical insights into the effect of shear on in situ reduction of graphene oxide in PVDF: assessing by rheo-dielectric measurements. In: MATERIALS RESEARCH EXPRESS, 3 (6).

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Abstract

In situ reduction of graphene oxide (GO) during the preparation of conducting polymeric nanocomposites has been explored recently. In this study, the in situ reduction of GO in poly (vinylidene fluoride) (PVDF) under different conditions like quiescent, high and low shear, pre-shear has been investigated in detail. To accomplish this, PVDF/GO composites were prepared by both melt and solution blending. The bulk electrical conductivity of melt mixed composites, which had undergone extensive shear during preparation, was monitored by a rheo-dielectric setup and compared with the composites which experienced low shear. In addition, the bulk electric conductivity was also measured in situ for the composites that had undergone quiescent compositing. Comprehensive characterization of the composites reveals that GO is in situ reducing under all processes but the improvement in conductivity is dependent on the adopted process. Compression molded samples, which were annealed for 45 min, showed highest melt conductivity among all the adopted processes. The intense shearing of composites at high temperature in melt extrusion led to re-stacking of graphene sheets and resulted in decreased bulk electrical conductivity. Surprisingly, melt conductivity decreases with shear and time in all composites. This study can help in understanding the reduction of GO during intense shearing of composites.

Item Type:	Journal Article
Publication:	MATERIALS RESEARCH EXPRESS
Additional Information:	Copy right of this article belongs to the IOP PUBLISHING LTD, TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
Department/Centre:	Division of Mechanical Sciences > Chemical Engineering Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	22 Oct 2016 08:56
Last Modified:	22 Oct 2016 08:56
URI:	http://eprints.iisc.ac.in/id/eprint/54954

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