PANI/CFO@CNTs ternary composite system for EMI shielding applications

With the advancement of modern communication technologies and the internet of things (IoT), the manufacturing of light, flexible, and high-performance electromagnetic interference (EMI) shields is imperative to minimize harmful effects of radiation on humans and electronic devices. Lightweight ferrites/carbon allotropes/polymer-based ternary composites with abundant interfaces are potential candidates for excellent absorption materials due to their high attenuation capability and impedance matching. We report EMI shielding properties of composites made of carbon nanotubes (CNTs) decorated with cobalt ferrite (CFO) nanoparticles and coated with polyaniline (PANI). The electromagnetic properties of the CFO@CNTs binary composite have been fine-tuned by varying the weight percentage of CNTs. The formation of CFO, CNTs and emeraldine form of PANI was confirmed by XRD and Raman spectroscopy. Transmission electron microscopy (TEM) revealed uniform attachment of CFO nanoparticles to the walls of CNTs, formation of 3D networks in the CFO@CNTs binary composite and its effective encapsulation by PANI. Benefiting from the controllable composition, 3D networking, porous structure of PANI, and strong complementary effect between CFO and CNTs (source of magnetic and dielectric losses), the PANI/CFO@CNTs ternary composite exhibited superior EMI shielding characteristics with a total shielding effectiveness of 16.80 dB corresponding to 97.90 % attenuation at a thickness of 2 mm. Considering the excellent EMI shielding properties, PANI/CFO@CNTs ternary composites can be employed as high-performance EMI shields.