Always cite the published version, so the author(s) will receive recognition through services that track citation counts, e.g. Scopus. If you need to cite the page number of the author manuscript from TSpace because you cannot access the published version, then cite the TSpace version in addition to the published version using the permanent URI (handle) found on the record page. Abstract. Thermoelectric effect is defined as the revisable translation between thermal and electrical energy. In this paper, we investigate the properties of p-type poly(vinylidene fluoride) (PVDF) based polymer composite foams that can be used in next generation energy harvesting applications. The composites were created via continuous melt blending method. Multi-walled carbon nanotubes (MWCNTs) and graphene nano-platelets (GNPs) were used as secondary phases to strengthen the electrical conductivity of the composites. Foam structures were later generated via super-critical carbon dioxide saturation method. We study the material properties between solid and foam samples; the results indicate a dramatic increase in overall thermoelectric properties for GNP foamed samples. We also report at least an order decreased in thermal conductivity which is in favor of thermoelectric effect. An unexpected drop in electrical conductivity was observed after the foaming process and can be explained by large volumetric expansion of the foam. Finally we report the Seebeck coefficient for both types of composite foams: 11 μV/K for 5 wt% MWCNT/PVDF foam and 58 μV/K for 15 wt% GNP/PVDF foam.
IntroductionThermoelectric (TE) effect is known as the direct conversion between electrical and thermal energy and such effect can be explained by three different phenomena: Seebeck effect, Peliter effect, and Thomson effect. When a temperature gradient is applied to a circuit that consists of two different electric conductors, a small current can be observed which is called the Seebeck effect. The opposite phenomenon is called the Peliter effect, of which the junctions of the two conductors may either absorb or release heat when a voltage is supplied to the circuit. Lastly, the Thomson Effect states that when an electric current is passing through a conductor, certain amount of heat (Thomson heat) would be released or absorbed by the material and such heat is does not include the non-reversible Joule heating which is generated from the electric resistance nature of the material [1]. Seebeck effect is currently being implemented in verity types of temperature sensors or thermocouples [2] while the Peliter effect can be applied in different types of heat engines and coolers [3]. Other than temperature sensors, Seebeck effect also being widely researched for energy harvesting