Electrostatic self-assembly of 2D/0D Ti3C2Tx MXene/BaFe12O19 nanostructures for high-performance electromagnetic interference shielding

Suppressing secondary electromagnetic reflection while maintaining high shielding effectiveness remains a central challenge for conductive MXene-based electromagnetic interference (EMI) shields. Here, 2D/0D MXene/BaFe 12 O 19 nanostructures were constructed by electrostatic self-assembly. The assembly combined negatively charged MXene nanosheets with poly(diallyldimethylammonium chloride) (PDDA)-functionalized BaFe 12 O 19 nanoparticles. This surface-charge-mediated assembly suppresses MXene restacking, creates dielectric–magnetic heterointerfaces, and systematically regulates the complex permittivity and permeability. The incorporation of BaFe 12 O 19 moderates the excessive permittivity of MXene and introduces resonance-type magnetic loss. These interrelated effects thereby alleviate the dielectric–magnetic imbalance, allowing more incident electromagnetic energy to enter and be attenuated within the shield. At a thickness of 1 mm paraffin-based toroidal specimen, MXF-3 reaches a maximum total shielding effectiveness (SE T ) of 58.0 dB at 10 GHz, with an absorption shielding effectiveness (SE A ) = 48 dB and reflection shielding effectiveness (SE R ) = 10 dB. Spin-polarized density functional theory calculations reveal orbital coupling and static charge redistribution at the MXene/BaFe 12 O 19 interface, providing electronic-structure insight into the interfacial interactions. These results demonstrate that electrostatic self-assembly is an effective route for preparing powder-based MXene/hexaferrite functional fillers for X-band EMI shielding. Download: Download high-res image (292KB) Download: Download full-size image