Simple large-scale method of recycled graphene films vertical arrangement for superhigh through-plane thermal conductivity of epoxy composites

Abstract Highly thermal conductive polymer-based materials are essential for modern microelectronic devices. However, conventional thermal conductive polymer-based composites exhibit constrained thermal conductivity even at a high content of highly thermal conductive fillers due to the lack of significant thermal conductive paths. In this work, effective thermal conductive paths were constructed with macro recycled graphene film fragments that were vertically arranged by a method of area restricting in the vertical direction under mechanical force. The resulting composites with vertically arranged structure displayed highly through-plane thermal conductivity of 20.97 W m−1 K−1 at 32.63 wt% graphene film fragments loading. Another three contrast experiments in different adding ways of fillers were as well accomplished to confirm the excellent vertically arranged structure. This study not only provides a simple way to obtain highly thermal conductive composites but also offers a strategy of making full use of wastes from industrial applications. The facile method for obtaining the superhigh though-plane thermal conductivity enlightens us to practical application. The recycled graphene films as millimeter-particles in this study can be expanded to other millimeter-particles arrangements. The mechanical force used for vertically arranged structure can be broadened to other forces such as vacuum or hydraulic pressure.