Thermal and dielectric properties of clay/epoxy nanocomposites with low percentage of graphite oxide

This work is concerned with hybrid nanocomposite materials that contain both clay and graphite oxide incorporated in an epoxy matrix. In order to assess the challenge of improving the thermal conductivity while not changing or even improving the electrical properties, a new composite system was designed by applying an additional thermal conductive phase represented by the graphite oxide. In this paper, extremely low quantities of graphite oxide were used (going from 0.0012 to 0.0025 wt%) in order to avoid the forming of an electrical conduction percolation network. The impact of the additional filler on the thermal and electrical properties of the clay/graphite oxide/epoxy nanocomposites were investigated. Using thermal conductivity measurements, it was found that even for low quantities of GO filler added to the clay/epoxy nanocomposite material, the thermal conductivity is improved significantly. Moreover, using dielectric characterization techniques (Dielectric Spectroscopy, Space Charge or Dielectric Breakdown measurements), it was found that the electrical properties of the material remain unchanged or are slightly improved by the extra graphite oxide filler.