A Spiral Graphene Framework Containing Highly Ordered Graphene Microtubes for Polymer Composites with Superior Through-Plane Thermal Conductivity

Comprehensive Summary As the power density of electronic devices increases, there has been an urgent demand to develop highly conductive polymer composites to address the accompanying thermal management issues. Due to the ultra-high intrinsic thermal conductivity, graphene is considered a very promising filler to improve the thermal conductivity of polymers. However, graphene-based polymer composites prepared by the conventional mixing method generally have limited thermal conductivity, even under high graphene loading, due to the failure to construct efficient heat transfer pathways in the polymer matrix. Here, a spiral graphene framework (SGF) containing continuous and highly ordered graphene microtubes was developed based on a modified CVD method. After embedding into the epoxy (EP) matrix, the graphene microtubes can act as efficient heat pathways, endowing the SGF/EP composites with a high through-plane thermal conductivity of 1.35 W center dot m(-1)center dot K-1 at an ultralow graphene loading of 0.86 wt%. This result gives a thermal conductivity enhancement per 1 wt% filler loading of 710%, significantly outperforming various graphene structures as fillers. In addition, we demonstrated the practical application of the SGF/EP composite as a thermal interface material for efficient thermal management of the light-emitting diode (LED).

Automated summary

With the increasing power density of electronic devices, there is a growing demand for highly conductive polymer composites. Graphene, with its ultra-high thermal conductivity, is considered a promising filler to enhance the thermal conductivity of polymers. However, conventional mixing methods for preparing graphene-based polymer composites often result in limited thermal conductivity, due to the failure to create efficient heat transfer pathways in the polymer matrix. In this study, a spiral graphene framework was developed using a modified chemical vapor deposition method, which significantly improved the through-plane thermal conductivity of epoxy-based composites even at a low graphene loading of 0.86 wt%. Furthermore, the practical application of the composite in thermal management for light-emitting diodes (LEDs) was demonstrated.