Graphene-based thermally conductive material cross-linked by poly(ethylenimine) with high thermal and mechanical properties

In recent decades, graphene has become a very promising thermal management material due to its excellent thermal performance and flexibility. The interaction between adjacent graphene nanosheets, on the other hand, is Van der Waals, limiting the improvement of thermal performance and flexibility of graphene-based heat-conducting films. In this work, a poly(ethylenimine) (PEI)/graphene oxide (GO) /carbon nanotubes (CNTs) heat-conducting film was fabricated, in which PEI acts as a cross-linking agent to form cross-links between GO nanosheets, followed by carbonization and graphitization. Further investigations illustrate that the graphitized PEI/GO/CNTs film has excellent mechanical properties with a tensile strength of 198.3 ± 15.6 MPa and excellent thermal performance with an in-plane thermal conductivity of 1038.4 ± 25.07 W m −1  K −1 and a through-plane thermal conductivity of 7.14 ± 0.25 W m −1  K −1 . The graphene-based thermal conducting films have great potential in various fields, such as electronics, aerospace, 5G, etc. Graphical abstract