High electrical conductivity in polydimethylsiloxane composite with tailored graphene foam architecture

Abstract

Graphene foam has huge potential applications in thermal management owing to their unique three-dimensional (3D) interconnected structure. It’s still a challenge to construct graphene foam architecture via facile and efficient method to reach superior property with low loading of nanofillers. Here, we report a polymer-template-assisted assembly strategy to develop 3D graphene architecture that is incorporated into polydimethylsiloxane (PDMS) composite with high electrical conductivity and thermal property. A free-standing foam structure has been assembled with graphene nanosheets, which was exfoliated in low-boiling-point chloroform with assistance of hyperbranched polyethylene as polymer stabilizer against aggregation via CH-π noncovalent interactions. The resultant graphene foam/PDMS composite exhibits high thermal conductivity of 0.22 W m−1 K−1 and high electrical conductivity of 9.1 × 10−3 S cm−1 at relatively low loading as 0.7 wt%, which is ascribed to the efficient transfer of charge carrier and thermal phonon along the graphene skeleton. This work demonstrates that the PDMS composite incorporated with graphene foam is a promising candidate for thermal interface materials with high electrical conductivity.