Multifunctional 3D MXene@MDCF Nanoarchitectures via Hierarchical Networks Self‐Assembled Strategy Achieving Superior Electromagnetic Wave Absorption and Flame Retardancy with Enhanced Thermal Management

ABSTRACT To address the critical challenges of heat accumulation and electromagnetic interference in high‐power electronic packaging, which severely restrict the performance stability and service life of electronic devices. This study develops a multifunctional epoxy‐based composite (MXene@MDCF/EP) through synergistically designed electrostatic self‐assembly. By leveraging the opposite surface potentials of MXene (−39.5 mV) and melamine‐derived carbon foam (MDCF, +23.4 mV), we constructed a 3D hierarchical network where MXene nanosheets are uniformly anchored onto MDCF scaffolds. This unique architecture simultaneously resolves MXene's stacking limitations and enhances impedance matching. At a low filler loading of 10 wt.%, the composite achieves exceptional electromagnetic wave absorption with a minimum reflection loss (RL _min ) of −55.76 dB and a maximum effective absorption bandwidth (EAB _max ) of 5.20 GHz, outperforming most reported MXene‐based absorbers at reduced filler content. The dual‐pathway thermal network elevates thermal conductivity to 0.602 W·m ⁻¹ ·K ⁻¹ (213.5% higher than pure EP), enabling efficient heat dissipation. Furthermore, the composite exhibits superior flame retardancy, reducing peak heat release rate and total heat release by 25.7% and 30.46%, respectively, through the formation of dense carbon layers. This work provides a cost‐effective strategy for multifunctional electronic packaging materials with integrated wave‐absorption, thermal management, and flame‐retardant properties.