An Ingenious Strategy to Construct Helical Structure with Excellent Electromagnetic Shielding Performance

Herein, a unique, 3D helical composite with excellent electromagnetic interference (EMI) shielding capability is fabricated. The alkali treated natural cotton fiber (NaCF) is adopted as the helical templet. The compacted polyaniline (PANI) clusters are grafted over NaCF surface via in situ polymerization technology. The correlation between structure and electromagnetic characteristics is investigated in details. The high doping degree and high crystalline phase of PANI coating layer results in the enhanced electrical conductivity. The improved polarization combined with high electrical conductivity boosts the dielectric loss and microwave attenuation properties. The analysis of skin depth, attenuation constant, and the comparisons of theoretical predictions and experimental results are conducted to investigate the effects of helical structure on the fundamental EMI shielding mechanisms. Absorption is the dominating microwave shielding mechanism due to the efficient multiple reflection. The EMI shielding effectiveness (SE) up to 48.83 dB (i.e., >99.998% attenuation) indicates excellent shielding capability. This SE value is fairly superior among PANI‐based shielding composites. All the above results demonstrate a significant fundamental basis for designing a novel high‐performance EMI shielding material. The results and techniques also promise an ingenious and efficient strategy to achieve light‐weight and thin PANI‐based composite for shielding application potentials.