Vertically aligned, ultralight and highly compressive all-graphitized graphene aerogels for highly thermally conductive polymer composites

Abstract

Thermally conductive polymer composites with satisfactory mechanical performances are highly required for practical thermal management applications as thermal interface materials. Herein, all-graphitized graphene aerogels with highly aligned graphene network are fabricated with graphene oxide hydrogels as the precursor by directional-freezing followed by freeze-drying and subsequent graphitization at 2800 °C, which exhibit excellent thermal and electrical conductions and superelasticity. Thanks to the vertically aligned conductance network composed by the graphitized graphene sheets, an epoxy composite with only 0.75 vol% of the high-quality graphene exhibits an excellent vertical thermal conductivity of 6.57 W/(mK), which is among the highest through-plane thermal conductivities of polymer composites at similar loading of carbon nanofillers, and more than 37 times higher than that of neat epoxy matrix. The thermally and electrically conductive composite also exhibits greatly improved storage modulus, compressive strength and compressive strain at break.