Magnetic metal nanoparticles coated polyacrylonitrile textiles as microwave absorber

Polyacrylonitrile (PAN) textiles with 2mm thickness are coated with magnetic nanoparticles in coating baths with Ni, Co and their alloys via an electroless metal deposition method. The crystal structure, morphology and magnetic nature of composites are investigated by X-ray Powder diffraction, Scanning Electron Microscopy, and dc magnetization measurement techniques. The frequency dependent microwave absorption measurements have been carried out in the frequency range of 12.4–18GHz (X and P bands). Diamagnetic and ferromagnetic properties are also investigated. Finally, the microwave absorption of composites is found strongly dependent on the coating time. One absorption peak is observed between 14.3 and 15.8GHz with an efficient absorption bandwidth of 3.3–4.1GHz (under −20dB reflection loss limit). The Reflection loss (RL) can be achieved between −30 and −50dB. It was found that the RL is decreasing and absorption bandwidth is decreasing with increasing coating time. While absorption peak moves to lower frequencies in Ni coated PAN textile, it goes higher frequencies in Co coated ones. The Ni–Co alloy coated composites have fluctuating curve of absorption frequency with respect to coating time. These results encourage further development of magnetic nanoparticle coated textile absorbers for broadband applications. ► Ni, Co and Ni–Co alloyed coatings on PAN were successfully prepared. ► The incorporation of magnetic nanoparticles leads to interfacial polarization. ► The composite prepared in Ni bath at 0.5min leads to a wider absorption bandwidth and minimum coefficient of reflection. ► About of −42dB, more than 99.99% of the microwave absorption.