Facile Synthesis of Hybrid NF/SMWCNT Hybrids for Electromagnetic Interference Shielding via Microwave-Assisted Combustion
摘要
The advancement of high-performance composite materials with superior structural, magnetic, and electromagnetic interference (EMI) shielding capabilities is a growing necessity in electronics, telecommunications, and defense applications. In this work, hybrid composites of spinel nickel ferrite (NF) and spiral multi-walled carbon nanotubes (SMWCNTs) were synthesized via a rapid, cost-effective microwave-assisted combustion method. These hybrid powders were embedded in an epoxy resin matrix to fabricate functional composites. X-ray diffraction (XRD) analysis confirmed the formation of a well-defined spinel phase, while vibrating sample magnetometry (VSM) revealed optimal magnetic properties with a saturation magnetization of 38.191 emu/g for the NF/2.0wt%SMWCNTs sample. This composition also demonstrated the most effective microwave absorption, achieving a minimum reflection loss of −17.6 dB at 12.8 GHz with a 3.0 mm thickness. Additionally, the highest EMI shielding effectiveness of 14.73 dB was recorded, attributed to enhanced dielectric loss and interfacial polarization induced by the homogeneously dispersed SMWCNTs, as verified through field-emission scanning electron microscopy (FESEM). These findings demonstrate the potential of NF/SMWCNT composites for advanced EMI shielding and microwave absorption applications in the Ku-band frequency range (12.0–18.0 GHz).