Designing Multifunctional Polymers and Composites by the Addition of Graphene Nanoplatelets
Lawrence Drzal, Michigan State University
The graphene structure of carbon is largely responsible for the unprecedentedly high levels of intrinsic mechanical, electrical, and thermal properties of carbon nanotubes (CNTs). Though the tubular graphene structure in the CNT is synthesized from a slow and costly ‘bottom-up’ approach, graphene itself can be inexpensively and efficiently produced in a nanoplatelet morphology (GNP) by a ‘top-down’ approach from natural graphite with properties competitive with those of CNTs. The nanoplatelet shape and controllable size—with thicknesses less than 5 nm and diameters ranging from sub-micron to 100 microns—can also improve barrier properties.
When graphene nanoplatelets are combined with thermoset or thermoplastic polymers at concentrations of only a few percent, the resulting GNP nanocomposites have substantially improved mechanical properties; electrical conductivity increases of ~10 orders of magnitude; thermal conductivity increases of ~100X; barrier property enhancement by factors of 5-10; and reduced flammability. Potential applications include transparent conductive films, components for fuel cells, lithium ion batteries, solar cells, and supercapacitors, among others. Examples with performance metrics and future challenges and opportunities for using these materials will be presented and discussed.