Graphite Nanoplatelets as Reinforcements for Polymers: Structural and Electrical Properties

摘要

Composites reinforced with nanoscopic graphite platelets were fabricated and their properties were investigated as a practical alternative to carbon nanotubes. The X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) results indicated that the graphite flakes were wellexfoliated to achieve platelets with thicknesses of 20 nm or less. Flexural tests and Differential Mechanical Thermal Analysis (DMTA) results show that nanocomposite materials made with these nanographite platelets have higher modulus than that of composites made with commercially available carbon reinforcing materials (i.e., PAN based carbon fiber, Vapor Grown Carbon Fiber [VGCF], and Nanoscopic High-structure Carbon Black). With the proper surface treatment, the graphite nanoplatelets in polymeric matrices also showed better flexural strength than composites with other carbon materials. Impedance measurements have shown that the exfoliated graphite plates percolate at below 3 volume percent, which is better than carbon fiber and comparable with other carbon materials, and exhibit a ～10 order of magnitude reduction in impedance at these concentrations.