J. Mater. Sci. Technol. ›› 2021, Vol. 86: 127-138.DOI: 10.1016/j.jmst.2021.01.041

• Research Article • Previous Articles     Next Articles

Magnetic ferrite/carbonized cotton fiber composites for improving electromagnetic absorption properties at gigahertz frequencies

Sateesh Bandarua,*(), Narashima Murthyb, Ravindra Kulkarnic, Niall J. Englisha,*()   

  1. aSchool of Chemical and Bioprocess Engineering, University College Dublin, Belfield, Dublin 4, Ireland
    bScinva Chemicals and Pharmaceuticals Pvt Ltd, Kumbalagodu Industrial Area, Bangalore, India
    cBVDU’s Poona College of Pharmacy, Erandawane, Pune, India
  • Received:2020-12-28 Accepted:2021-01-16 Published:2021-09-30 Online:2021-09-24
  • Contact: Sateesh Bandaru,Niall J. English
  • About author:niall.english@ucd.ie (N.J. English).
    *E-mail addresses: sateeshpatrudu@gmail.com (S. Bandaru),

Abstract:

Ferrite/carbon composited materials, especially the bio-derived composited materials possessing both environmental friendliness and outstanding microwave absorption performance, attract numerous attentions for solving the “electromagnetic problem” in the Gigahertz frequency range. In this work, we demonstrate a bio-derived ferrite/carbon material by compositing functional carbonized cotton fibers (CCFs) and Fe3O4nanoparticles with optimized microwave-absorption properties. By adjusting the carbonization conditions systematically, the Fe3O4 loading contents and the microwave absorption properties can be varied simultaneously – and, indeed, optimized and tuned. The CCFs-3O4composites exhibited a minimum reflection-loss capacity RL(dB) of -56.8 dB at 10.9 GHz with a thickness of 1.67 mm, and its effective absorption bandwidth (RL(dB) <-20 dB) was found to broaden to 7.1 GHz. Electromagnetic characterizations, coupled with microstructure analyses, revealed that the enhancement in microwave absorption was triggered by the different microstructures of CCFs-Fe3O4composites - attributable to the different carbonization processes. These different conditions result in different amounts of Fe3O4attachment sites and lead to the enhancement of dielectric polarization at localized microstructures. The present work of bio-derived ferrite/carbon materials has important implications in understanding structure-performance relationships in dielectric-magnetic materials, and, meanwhile, could well be extended to a microwave-absorber design approach.

Key words: Electromagnetic absorption, Bio-derived material, Dielectric-magnetic composite, Interfacial polarization