Synthesis and electromagnetic absorption properties of polypyrrole/BaFe12O19-Ni0.8Zn0.2Fe2O4/multi-walled carbon nanotube composites

The nanocomposite of hard ferrite (BaFe12O19)/soft ferrite (Ni0.8Zn0.2Fe2O4) was prepared by using a sal-gel method, and then the polypyrrole/nanocomposite ferrite/multi-walled carbon nanotube composites were fabricated by an in situ polymerization process. Experimental results, such as X-ray diffraction (XRD), transmission electron microscope (TEM), fourier transform infrared (FTIR) and Raman spectra analyses indicated the formation of PPy and BaFe12O19-Ni0.8Zn0.2Fe2O4 on the surface of carbon nanotubes. The conductivities of the composites were enhanced with the increasing of MWCNTs' content and the value reached 19.514 S/cm in the presence of 30% MWCNTs. However, the magnetic properties did not show any obvious changes. The electromagnetic properties of MWCNTs (5%) composites exceeding -10 dB ranged from 8.5 to 10.3 GHz and the maximum loss value was -25.46 dB at 8.9 GHz. The introduction of MWCNTs had an important influence on the electrical and microwave absorbing properties of the nanocomposite. (C) 2014 Elsevier Ltd. All rights reserved.