Preparation and electromagnetic and microwave absorbing properties of Fe-filled carbon nanotubes

The carbon nanotubes (CNTs) were filled with Fe nanoparticles via a wet-chemical method. Microwave absorption, complex permittivity and permeability of the Fe-filled CNTs have been investigated. The real part (epsilon') and imaginary part (e '') of the permittivity of the Fe-filled CNTs are smaller than those of CNTs. While the real part (mu') and imaginary part (mu '') of the permeability and the magnetic dissipation factors tg delta(mu) (mu ''/mu ') of the Fe-filled CNTs are bigger than those of CNTs. The Fe-filled CNT/epoxy composites achieved a reflection loss below -10 dB (90% absorption) at 11.8-14.7 GHz, and the minimum value is -31.71 dB at 13.2 GHz. The microwave enhancement absorption of Fe-filled CNT/epoxy composites was attributed to both dielectric and magnetic losses. The microwave-absorbing peak of the CNT/epoxy composites moves to the higher frequency by filling the Fe nanoparticles into the CNTs. (c) 2008 Elsevier B.V. All rights reserved.