Development of the Thermal Flash Method for Characterization of Carbon Nanofibers

Abstract

The transient thermal flash technique, originally developed for testing low thermal diffusivity micro/nanofibers, was implemented for measuring the thermal conductivity of vapor-grown carbon nanofibers. The present technique uses a microfabricated strip of gold, which acts both as a heater and a temperature sensor. The modifications were validated against commercially available carbon fibers (Pyrograf® – I from Applied Sciences, Inc. and Mitsubishi K13D2U) and the results obtained were seen to match values previously reported in the literature. The carbon nanofibers reported in this article were also obtained from Applied Sciences, Inc. and are known as PR-25, belonging to the Pyrograf® – III family of nanofibers. The thermal conductivities calculated based on the experimentally determined values of diffusivity along with the specific heat capacity and density of graphite were around 1100 W/m-K and 1700 W/m-K, respectively for the nanofibers heat treated to 1100 °C and 3000 °C.