Interfacial polymerization preparation of polyaniline fibers/Co0.2Ni0.4Zn0.4Fe2O4 urchin-like composite with superior microwave absorption performance

In this work, a polyaniline (PANI) fibers/Co0.2Ni0.4Zn0.4Fe2O4 (CNZF) composite (mass ratio of PANI to CNZF is 1:1) with a novel urchin-like structure was successfully fabricated through interfacial polymerization. The CNZF was synthesized by the sol-gel method, and whereafter, the PANI fibers were grafted onto the CNZF surface through in-situ polymerization. Structural and morphological properties were systematically investigated by using field emission scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectra (FTIR). In the frequency range of 2-18 GHz, the microwave absorption properties of samples were investigated by using vector network analyzer (VNA). The results demonstrated that the microwave absorbing capability of the PANI/CNZF composite was superior to the pure CNZF or PANI. For the PANI/CNZF composite, its optimal absorption peak reached −41.9 dB at 10.48 GHz with a 2.8 mm thickness and the effective absorption bandwidth (RL < −10 dB) was 3.76 GHz. Moreover, the maximum effective bandwidth of PANI/CNZF reached 5.24 GHz (12.66-17.90 GHz) with a thinner thickness of 1.9 mm. On account of advanced impedance matching and increased interfacial effects, the PANI/CNZF composite possessed excellent microwave absorption properties and can be used as absorbers with strong absorption, extended absorbing bandwidth, and thin thickness.