Electromagnetic and microwave absorbing properties of multi-walled carbon nanotubes filled with Ag nanowires

The multi-walled carbon nanotubes (MWNTs) were filled with long continuous Ag nanowires via a wet chemical method. The diameters of Ag nanowires were in the range of 10–20 nm, and lengths of 100–1500 nm. Microwave absorption and complex permittivity and permeability of MWNTs filled with Ag nanowires have been investigated in the range of 2–18 GHz, respectively. The reflection loss of the Ag nanowire filled MWNT/epoxy composites with the thickness of 1.0 ± 0.1 mm is below −10 dB in the range of 7.2–9.0 GHz, and the minimum value is −19.19 dB at 7.8 GHz. The microwave absorption of Ag nanowire filled MWNT/epoxy composites can be mainly attributed to the dielectric loss rather than magnetic loss. The absorption peak frequency of the MWNT/epoxy composites with thickness of 1 mm can be tuned by filling Ag nanowire into MWNTs.