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Controlled structure evolution of graphene networks in polymer composites

DOI: 10.1021/acs.chemmater.7b04343 DOI Help

Authors: Stephen Boothroyd (University of Durham) , David W. Johnson (University of Durham) , Michael P. Weir (The University of Sheffield) , Carl D. Reynolds (University of Durham) , James M. Hart (University of Durham) , Andrew J. Smith (Diamond Light Source) , Nigel Clarke (The University of Sheffield) , Richard L. Thompson (University of Durham) , Karl S. Coleman (University of Durham)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemistry Of Materials

State: Published (Approved)
Published: February 2018
Diamond Proposal Number(s): 15187

Open Access Open Access

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 further 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.

Journal Keywords: Composites; Electrical properties; Two dimensional materials; Electrical conductivity; Polymers

Subject Areas: Materials, Chemistry, Physics


Instruments: I22-Small angle scattering & Diffraction

Added On: 19/02/2018 14:00

Documents:
acs.chemm3886ater.pdf

Discipline Tags:

Physical Chemistry Materials Science Composite Materials Polymer Science Physics Soft condensed matter physics Chemistry

Technical Tags:

Scattering Small Angle X-ray Scattering (SAXS)