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High‐strength conductive pristine graphene/epoxy composites are prepared by two simple processing methods – freeze dry/mixing and solution processing. PVP‐stabilized graphene is aggregation‐resistant and allows for excellent dispersion in both the resin and final composite, as confirmed by optical microscopy and SEM images. The superior dispersion quality results in excellent nanofiller/matrix load transfer, with a 38% increase in strength and a 37% improvement in modulus for 0.46 vol% graphene loading. The composites have a very low electrical percolation threshold of 0.088 vol%. Despite the effectiveness of both methods, the freeze‐drying method is more promising and versatile enough to be used for graphene dispersion in a wide range of other composite precursors.

We demonstrate a novel in situ polymerization technique to develop localized polymer coatings on the surface of dispersed pristine graphene sheets. Graphene sheets show great promise as strong, conductive fillers in polymer nanocomposites; however, difficulties in dispersion quality and interfacial strength between filler and matrix have been a persistent problem for graphene-based nanocomposites, particularly for pristine graphene. With this in mind, a physisorbed polymer layer is used to stabilize graphene sheets in solution. To create this protective layer, we formed an organic microenvironment around dispersed graphene sheets in surfactant solutions, and created a nylon 6, 10 or nylon 6, 6 coating via interfacial polymerization. Technique lies at the intersection of emulsion and admicellar polymerization; a similar technique was originally developed to protect luminescent properties of carbon nanotubes in solution. These coated graphene dispersions are aggregation-resistant and may be reversibly redispersed in water even after freeze-drying. The coated graphene holds promise for a number of applications, including multifunctional graphene-polymer nanocomposites.

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Pristine graphene/polyvinyl alcohol (PVA) nanofibers were prepared by electrospinning an aqueous solution of polyvinylpyrrolidone‐stabilized graphene and PVA. This is the first report of electrospun nanofibers reinforced with dispersed pristine graphene. We examine the relationship between graphene loading and critical electrospinning parameters. Microscopy indicates uniform fiber formation and excellent graphene dispersion within the fiber. Rheological data indicates that the excellent level of graphene dispersion enhances the modulus of the polymer by 205%. We also find that the graphene significantly increases the fibers' thermal stability (increase of 15°C) and crystallinity (59% increase) above the baseline. In fact, the graphene may act as nucleating points for increased crystallinity. These graphene/polymer nanofibers have the potential to serve in a variety of applications, including electrodes, conductive wires, and biomedical materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013