High-Performance Pristine Graphene/Epoxy Composites With Enhanced Mechanical and Electrical Properties

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.