Controlled Structure Evolution of Graphene Networks in Polymer Composites

Boothroyd, Stephen C.; Johnson, David W.; Weir, Michael P.; Reynolds, Carl D.; Hart, James M.; Smith, Andrew J.; Clarke, Nigel; Thompson, Richard L.; Coleman, Karl S.

doi:10.1021/acs.chemmater.7b04343

Controlled Structure Evolution of Graphene Networks in Polymer Composites

Boothroyd, Stephen C.; Johnson, David W.; Weir, Michael P.; Reynolds, Carl D.; Hart, James M.; Smith, Andrew J.; Clarke, Nigel; Thompson, Richard L.; Coleman, Karl S.

Authors

Stephen C. Boothroyd

David W. Johnson

Michael P. Weir

Carl D. Reynolds

James M. Hart

Andrew J. Smith

Nigel Clarke

Dr Richard Thompson r.l.thompson@durham.ac.uk
Associate Professor

Professor Karl Coleman k.s.coleman@durham.ac.uk
Academic Visitor

Abstract

Exploiting graphene’s exceptional physical properties in polymer composites is a significant challenge because of the difficulty in controlling the graphene conformation and dispersion. Reliable processing of graphene polymer composites with uniform and consistent properties can therefore be difficult to achieve. We demonstrate distinctive regimes in morphology and nanocomposite properties, achievable through systematic control of shear rate and shear history. Remarkable changes in electrical impedance unique to composites of graphene nanoplates (GNPs) are observed. Low shear rates ≤ 0.1 s-1 break up the typical GNP agglomerates found in graphene composites, exfoliate the GNPs to fewer graphene layers and reduce orientation, enhancing electrical conductivi-ty in the composite materials. Whereas, at higher shear rates GNP orientation increases and the conductivity reduces by four orders of magnitude, as the graphene filler network is broken down. The structure of the composite continues to evolve, reflected in fur-ther changes in conductivity, after the shear force has been removed and the process temperature maintained. This work provides critical insights for understanding and controlling GNP orientation and dispersion within composites and will have important consequences in the industrial processing of graphene polymer composites via the informed design and choice of processing conditions.

Citation

Boothroyd, S. C., Johnson, D. W., Weir, M. P., Reynolds, C. D., Hart, J. M., Smith, A. J., …Coleman, K. S. (2018). Controlled Structure Evolution of Graphene Networks in Polymer Composites. Chemistry of Materials, 30(5), 1524-1531. https://doi.org/10.1021/acs.chemmater.7b04343

Journal Article Type	Article
Acceptance Date	Feb 14, 2018
Online Publication Date	Feb 14, 2018
Publication Date	Mar 13, 2018
Deposit Date	Feb 15, 2018
Publicly Available Date	Feb 16, 2018
Journal	Chemistry of Materials
Print ISSN	0897-4756
Electronic ISSN	1520-5002
Publisher	American Chemical Society
Peer Reviewed	Peer Reviewed
Volume	30
Issue	5
Pages	1524-1531
DOI	https://doi.org/10.1021/acs.chemmater.7b04343

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