Graphene loaded with nano-Cu as a highly efficient foam interface material with excellent properties of thermal-electronic conduction, anti-permeation and electromagnetic interference shielding

Strengthened conductive shielded graphene/nano-Cu/crosslinking polyurethane (CPU) foam with ultrahigh interfacial functions was newly fabricated, involving the use of nano-assembly-freeze extraction route. The 3D supported modified graphene-nano-Cu (GC) interface were analyzed and verified efficiently by FTIR, XRD, XPS spectra and SEM, TEM images. Towards the CPU foams doped with GC network, surface polarity was weakened efficiently, and the anti-permeation efficiency was significantly improved due to the special positive piling behaviors of nanosheets. The initial decomposition temperature (enhanced by ∼22.2%) was efficiently delayed on account of heat transfer and doping protection. Thermal conductivity consistently fitted with modified Maxwell-Garnett method (D ∼ 5, K p /Km ∼ 1000) was increased by ∼338% due to the collaborative formation of phonon-electron transmission network. More importantly, the electric conductivity was increased by orders of magnitude, along with the verification of 3D synergistic transmission network using percolation threshold. As compared to the pure CPU material, a maximum electromagnetic interference shielding (EMI) effectiveness of over 55 dB in the frequency range of 0–9 GHz was demonstrated on the interface with only ∼0.87 vol% GC doping. All these suggest that the CPU foams simply doped with characteristic GC possesses a great potential to be used as lightweight, highly conductive, anti-penetrative and stable anti-interference materials.