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Highly Conductive Multifunctional Graphene Polycarbonate NanocompositesGraphene nanosheet bisphenol A polycarbonate nanocomposites (0.027 2.2 vol %) prepared by both emulsion mixing and solution blending methods, followed by compression molding at 287 C, exhibited dc electrical percolation threshold of approx.0.14 and approx.0.38 vol %, respectively. The conductivities of 2.2 vol % graphene nanocomposites were 0.512 and 0.226 S/cm for emulsion and solution mixing. The 1.1 and 2.2 vol % graphene nanocomposites exhibited frequency-independent behavior. Inherent conductivity, extremely high aspect ratio, and nanostructure directed assembly of the graphene using PC nanospheres are the main factors for excellent electrical properties of the nanocomposites. Dynamic tensile moduli of nanocomposites increased with increasing graphene in the nanocomposite. The glass transition temperatures were decreased with increasing graphene for the emulsion series. High-resolution electron microscopy (HR-TEM) and small-angle neutron scattering (SANS) showed isolated graphene with no connectivity path for insulating nanocomposites and connected nanoparticles for the conductive nanocomposites. A stacked disk model was used to obtain the average particle radius, average number of graphene layers per stack, and stack spacing by simulation of the experimental SANS data. Morphology studies indicated the presence of well-dispersed graphene and small graphene stacking with infusion of polycarbonate within the stacks.
Document ID
20110016126
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Yoonessi, Mitra (NASA Glenn Research Center Cleveland, OH, United States)
Gaier, James R. (NASA Glenn Research Center Cleveland, OH, United States)
Date Acquired
August 25, 2013
Publication Date
November 17, 2010
Subject Category
Composite Materials
Report/Patent Number
E-17990
Funding Number(s)
CONTRACT_GRANT: NNC07BA13B
WBS: WBS 561581.02.10.03.10
CONTRACT_GRANT: NSF DMR-9986442
Distribution Limits
Public
Copyright
Other