Layered double hydroxide embedded in loofah-derived biocarbon composites towards broadband electromagnetic wave absorption and enhanced flame retardancy

The rising utilization of high-frequency and high-power electronic equipments necessitates the advancement of multifunctional green packaging materials characterized by electromagnetic wave absorption, high thermal conductivity, and flame retardancy. Achieving these properties while maintaining lightness and environmental sustainability remains a critical challenge. In this study, carbonized loofah sponge and layered double hydroxides (CLS@LDH) multifunctional green nanocomposites were developed from loofah vine waste using direct in situ growth strategy. The incorporation of LDH improves impedance matching and interface polarization. It is significant that a minimum reflection loss (RL_min) of −55.38 dB, coupled with an effective absorption bandwidth (EAB) of 7.14 GHz, is achieved with a mere 12 wt% filling ratio. In addition, the unique complex interwoven 3D biomass network and the formation of a gas protection barrier by the decomposition of LDH at high temperatures contribute to 81.36 % enhanced thermal conductivity compared to that of epoxy resin (EP). This improvement is accompanied by a notable reduction in both the peak heat release rate and total heat release rate, which decline by 32.5 % and 23.1 %, respectively. This work presents green production method for biomass-derived carbon composites, and the material integrates multifunctionality in terms of thermal conductivity, wave absorption, and flame retardancy. It demonstrates considerable for utilization as green electronic packaging material for broadband electromagnetic wave absorption.