M. T. Pettes, Ji, H. X., Ruoff, R. S., and Shi, L., “Thermal Transport in Three-Dimensional Foam Architectures of Few-Layer Graphene and Ultrathin Graphite,” Nano Letters, vol. 12, no. 6, pp. 2959–-2964, 2012.
At a very low solid concentration of 0.45±0.09 vol %, the room-temperature thermal conductivity (κGF) of freestanding graphene-based foams (GF), comprised of few-layer graphene (FLG) and ultrathin graphite (UG) synthesized through the use of methane chemical vapor deposition on reticulated nickel foams, was increased from 0.26 to 1.7 W m–1 K–1 after the etchant for the sacrificial nickel support was changed from an aggressive hydrochloric acid solution to a slow ammonium persulfate etchant. In addition, κGF showed a quadratic dependence on temperature between 11 and 75 K and peaked at about 150 K, where the solid thermal conductivity (κG) of the FLG and UG constituents reached about 1600 W m–1 K–1, revealing the benefit of eliminating internal contact thermal resistance in the continuous GF structure.