Dual-continuous graphene foam/poly(aryl ether ketone) composites with three-dimensional conductive networks for exceptional thermal conductivity and multifunctional performance

Abstract

Poly(aryl ether ketone) (PAEK)-based composites are highly desirable for thermal management in high-power electronic devices, yet their practical application is severely hindered by low intrinsic thermal conductivity and poor processability arising from high melt viscosity. Herein, we report a co-continuous composite architecture that simultaneously addresses these challenges by constructing a three-dimensional (3D) graphene foam (GF) skeleton via chemical vapor deposition using nickel foam as a template, followed by infusion of a fluorine-free phenolphthalein-based poly(aryl ether ketone) (EPEK-C) matrix pre-filled with multi-walled carbon nanotubes and graphene nanoplatelets (GnPs&MWCNTs). This unique design establishes a continuous and interconnected conductive network throughout the composite, effectively avoiding filler orientation-induced defects and minimizing interfacial thermal resistance. At a filler loading of 35.82 vol%, the resulting GF-GnPs&MWCNTs/EPEK-C composite exhibits outstanding in-plane and through-plane thermal conductivities of 19.9 W m⁻¹ K⁻¹ and 8.9 W m⁻¹ K⁻¹, respectively, representing enhancements of 7007% and 3078% compared to neat EPEK-C. Agari model analysis confirms the formation of a nearly ideal thermal percolating network, while Debye theory analysis reveals effective suppression of phonon scattering mechanisms. Benefiting from the highly conductive 3D graphene network, the composite also achieves an exceptional electrical conductivity of 1.68 × 10⁴ S m⁻¹ and an electromagnetic interference shielding effectiveness of 51.8 dB. Power coefficient analysis reveals that reflection dominates the shielding mechanism, attributed to the three-dimensional conductive network that provides multiple reflective surfaces and induces multiple internal reflections. The specific shielding effectiveness (SSE/t) reaches 6996 dB cm²/g. Furthermore, the material demonstrates rapid and stable Joule heating (∼1600 s) and efficient photothermal conversion (efficiency∼50.99%). This work presents a high-performance multifunctional composite for integrated thermal management and electromagnetic protection, offering a promising pathway for the development of next-generation multifunctional materials.