Vertically oriented carbon fiber skeletons bridged with graphene oxide for high thermal conductivity and superior compressibility in polymer-based thermal interface materials

High-performance polymer-based thermal interface materials (TIMs) are urgently required to facilitate efficient heat dissipation in electronic devices. However, achieving high thermal conductivity while maintaining satisfactory compressibility in composites remains challenging. In this study, we prepared highly thermally conductive carbon fiber (CF) skeletons with a vertically oriented porous structure by employing graphene oxide (GO) as an inorganic bridging agent via directional freezing techniques. Polydimethylsiloxane (PDMS) was then infiltrated into the skeletons to prepare CF-GO/PDMS composites. The incorporation of GO effectively bonded the individual CFs into continuous thermal transport pathways with reduced interfacial thermal resistance. The resulting CF-GO/PDMS composites achieved an exceptional thermal conductivity of 7.61 W·m -1 ·K -1 at 25.2 wt.% CF loading, corresponding to a high enhancement efficiency of 162.9% and representing a 57.6% increment compared to the CF/PDMS composites. Moreover, the composites demonstrated satisfactory compressibility, characterized by a low modulus of 6.91 MPa. Such outstanding performance is mainly ascribed to the vertical orientation of the highly conductive CF, formation of continuous thermal transport pathways, reduced interfacial thermal resistance and good deformability of the porous structure. The CF-GO/PDMS composites show great promise as advanced TIMs for use in the thermal management of electronic devices.