Electrical and thermal conductivity of aerogel/epoxy composites
This study investigates the electrical and thermal characteristics of two novel carbon aerogel composites containing Aerographite (AG) and a CNT foam. Aerographite of densities between 3 to 16 mg/cm3, and the CNT foam with densities of 17 and 31 mg/cm3 were prepared in the CVD process. Both aerogels were infiltrated with epoxy resin using a vacuum assisted infiltration technique that preserves the interconnected structure. The neat Aerographite showed a maximum electrical conductivity of 10.3 S/m while the CNT foam reached 1.7 S/m. In the epoxy composites the electrical conductivity of the neat materials is adopted, thus resulting in an enhancement of orders of magnitude when compared to neat epoxy. Thermal conductivity was studied using a Xenon flash method. First results show an improvement of thermal conductivity of the composite by 33 % at the low filler content of only 0.26 wt.-% for the Aerographite and of 91 % for the CNT foam at 2.7 wt.-% filler content.