Category: Transient Plane Source
Keywords: Aerogels, atomic force microscopy, Carbon nanotubes, CNTs, Electrical Conductivity, Figure of Merit, graphene, multi-walled, nanocomposites, Seebeck coefficient, Thermal Conductivity, Thermoelectric, X-ray Diffraction
Abstract: This paper proposes conducting carbon aerogels, composed of graphene and multi-walled carbon nanotubes, as an option for a thermoelectric material. The researchers found that this combination of materials increased the electrical conductivity and the Seebeck coefficient due to bridging effects, and decreased the thermal conductivity through high porosity and a uniquely structured 3-D skeleton. Atomic force microscopy and X-ray diffraction were used to quantify the physical structure of the aerogels, while the Hot Disk TPS system was used to measure the thermal conductivity of the samples. Results indicated that the open cell nature of the material produced depressed the thermal conductivity as the solid structure was not suited for good heat transport capabilities. The thermal conductivity of the nanocomposite aerogels was low, reaching a minimum of 0.056 W/mK. This, coupled with the increase in the Seebeck coefficient and the electrical conductivity, indicates that these could be a potential low cost thermoelectric material.
Reference: Composites Part B: Engineering 83(2015) 317-322