Search

Electron/phonon heat co-transfer, dielectric/magnetic dual loss, and 2D interlinked frameworks codetermine the ultrawide absorption bands, high thermal conductivity, and excellent electrical insulation of CF/M/C (M = Co, Ni, or Fe/Fe 3 O 4) 2D interlinked frameworks. [Display omitted] • A facile soaking-annealing strategy for CF/M/C (M = Co, Ni, Fe/Fe 3 O 4) 2DIFs. • Precisely modulating the interfaces, porosity, and defects. • Optimizing the thermal, electrical, and EMW absorbing properties. • Revealing the synergistic enhancement mechanism. Reasonable design of protective multifunctional materials is highly required for the safety protection of devices/personnel from electromagnetic radiation and heat damage in the 5G/6G era. Herein, a simple soaking-annealing route was adopted to carbonize filter paper into 2D interlinked carbon fiber frameworks inlaid with magnetic nanoparticles, and the products were referred to as CF/M/C 2DIFs (M = Co, Ni, or Fe/Fe 3 O 4). The concentration and type of metal ions as well as the annealing temperature of the CF/M/C 2DIFs were controlled to precisely modulate their composition, porosity, and defects. Results show that the CF/Co/C 2DIFs produced under T a = 600 °C and [Co2+] = 0.45 mol/L exhibit high thermal conductivity (2.931 ∼ 3.167 W/m·K) at small loads (10 ∼ 30 wt%) owing to not merely the presence of 2D interlinked path for electron/phonon heat co-transfer but the reasonable control of interface/defects for weakening phonon/electron defect/interface scattering. Also, the CF/Co/C 2DIFs can attenuate microwaves over a broad frequency range via dielectric/magnetic dual loss and 2DIFs, which boosts their loss ability and matching performance. The excellent performance in both heat dissipation and EM wave absorption proves that the CF/M/C 2DIFs can be a promising candidate for next-generation electronic packaging materials in heat management, military, and aerospace fields. [ABSTRACT FROM AUTHOR]

[Display omitted] • Controllable preparation of CeO 2 @C core–shell nanorods/nanofibers. • Optimizing the composition, structure, and properties of the composites. • A synchronous enhancement of heat conductance and EMW absorption. • Revealing the interfaces and oxygen vacancy dependent of performance. High-performance thermally conductive-microwave absorbing integrated materials are highly required to mitigate the severe electromagnetic pollution and overheating generated in electronic devices. However, the incompatibility between thermal conduction and microwave absorption impedes their collaborative development. Herein, an adjustment strategy for interface- and oxygen-vacancy-linkage was adopted to rationally construct CeO 2 @C core–shell nanorods/nanofibers (CSNRs/NFs) and cooperatively boost their electrical, thermal, and microwave absorption properties. A hydrothermal-annealing technique was employed to synthesize CeO 2 @C CSNRs/NFs. Their core–shell structure, oxygen vacancies/lattice defects, and length-to-diameter ratio were accurately adjusted by changing the annealed temperature (T a) and toluene volume (V). The CeO 2 @C CSNRs/NFs produced under T a = 600 °C and V = 1.5 mL exhibit high thermal conductivity (TC = 2.94 W/(m·K)) at a small load of 40 wt%. The large TC is mainly due to the weak phonon defect/interface scattering and electron/phonon co-transfer in a 3D continuous path consisting of a 1D structure. Furthermore, the CeO 2 @C CSNRs/NFs display strong microwave absorption (EAB max /d = 3.27 GHz/mm; RL min =− 50.98 dB) due to their various polarizations, tunable conduction loss, and multiple internal reflections. These results demonstrate that the CeO 2 @C CSNR/NFs are an ideal multifunctional material that protects against concurrent EM interference and excess heat in electronic packaging materials. [ABSTRACT FROM AUTHOR]