Effects of heat treatment on the thermal properties of highly nanoporous graphene aerogels using the infrared microscopy technique

Graphene aerogels (GAs), fabricated from graphene oxide (GO) suspensions using a mild chemical reduction method, are promising for many applications. Here we report the thermal conductivities of GAs having various graphene volume fractions from 0.67% to 2.5%, with and without annealing treatment, measured using a comparative infrared microscopy technique. The thermal conductivities of the GAs are measured to be 0.12-0.36 W/(m K). This is the first systematical study of the thermal properties of GAs and the results elucidate the factors limiting their thermal conductivities. The developed thermal measurement technique can be applied to other porous material systems.