Abstract
A high-conductivity graphite foam developed at Oak Ridge National Laboratory (ORNL) exhibits properties indicative of highly graphitic structure. Similar to highly-ordered natural flake graphite, the foam exhibits a peak in thermal conductivity at temperatures approaching liquid nitrogen. This is due to its highly-aligned graphitic structure along the cell walls. This paper explores the manufacturing process to identify processing conditions that most affect the properties of the foam, such that the production of the foam can be easily tailored to different applications. This paper also examines processing conditions for the precursor's preparation as well as additives to the precursor (such as graphene) on the resulting foam structure and thermal properties. It was found that heat treating the precursor mesophase to increase melt viscosity and decrease off gassing during foaming decreased the thermal conductivity of the final foams, however, it resulted in smaller pores. Additions of graphene platelets decreases the thermal conductivity of the foams while simultaneously decreasing the pore size as well. These tradeoffs are evident and present the manufacturer options to tailor the foams.
| Original language | English |
|---|---|
| Pages (from-to) | 43-54 |
| Number of pages | 12 |
| Journal | Carbon |
| Volume | 144 |
| DOIs | |
| State | Published - Apr 2019 |
Funding
The author would like to thank Rob Williams for his hard work on this program. Rob was a high school senior who conducted his Senior Research Portfolio on this research. He spent his afternoons conducting the experiments and characterization of the foams produced in this paper. The author would also like to thank Chris Pullins for his help and mentorship of Rob in the laboratory. Chris operated the equipment for Rob and helped him prepare samples in a professional manner. The author wishes to thank Tom Geer for performing the preparation of the samples for optical image analysis. The author would also like to thank Hsin Wang for his help with the thermal diffusivity testing. “The submitted manuscript has been authored by a contractor of the U.S. Government under contract No. DE-AC05-00OR22725. Accordingly, the U. S. Government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U.S. Government purposes.”
| Funders | Funder number |
|---|---|
| U.S. Government |