Synthesis of free-standing carbon nanotube buckypaper films decorated with Fe3O4 nanoparticles and polyaniline as highly effective electromagnetic shielding materials

A balance between electrical and magnetic properties is critical for electromagnetic shielding materials to achieve excellent electromagnetic interference (EMI) shielding and attenuation effectiveness across a broad frequency range. We have prepared free-standing buckypaper films (BPFP) decorated with Fe 3 O 4 particles and polyaniline (PANI) by a simple two-step method to meet this requirement. First, buckypaper films decorated with Fe 3 O 4 (BPF) were synthesized by the coprecipitation of Fe 2+ /Fe 3+ ions on buckypaper (BP) which was then coated with a polyaniline layer by the in situ polymerization of aniline monomers. Magnetic characterization revealed that the BPF and BPFP films had saturation magnetization ( M s ) values of 14.3 emu g −1 and 13.0 emu g −1 , respectively, confirming retention of the magnetic phase. The addition of Fe 3 O 4 nanoparticles and polyaniline to BP (30 μm) increased both the magnetic and dielectric losses due to the increased interfacial polarizations and anisotropy energy. 41 μm-thick BPF and BPFP films had an absorption-dominated shielding effectiveness of 35.1 dB and 36.4 dB, respectively, across the 5.85-18 GHz frequency band. These values are respectively 12.9% and 17.0% greater than that of pristine BP, highlighting the positive effect of Fe 3 O 4 -PANI heterostructures on electromagnetic wave dissipation. These films also had the tensile strength, flexibility, and lightness of BP, demonstrating exceptional promise for next-generation electromagnetic shielding materials. Download: Download high-res image (175KB) Download: Download full-size image