Microwave absorption behaviour of MWCNT based nanocomposites in X-band region

Multiwall carbon nanotube (MWCNT) based nanocomposites were prepared by a two-step process. Firstly, titanium dioxide (TiO2) coated MWCNT was prepared via sol-gel technique. In the second step, the acid modified MWCNTs were dispersed in the thermoplastic polyurethane matrix by solution blending process. Characterizations of the nanocomposites were done by X-ray diffraction analysis, X-ray photoelectron spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy and Energy-dispersive X-ray spectroscopy. Microwave absorption studies of the nanocomposites were carried out in X-band region. The microwave absorption result was discussed with the help of complex permittivity and permeability of the prepared radar absorbing material (RAM). The result showed superior microwave absorption property of the composite containing both TiO2 coated MWCNT and magnetite (Fe3O4). This result is due to the effective absorption of both electrical and magnetic components of the microwave. RAM-MW, RAM-Ti, RAM-Ti@MW and RAMTi@ MW/Fe and showed the maximum reflection loss of –16.03 dB at 10.99 GHz, –8.4 dB at 12.4 GHz, –36.44 dB at 12.05 GHz and –42.53 dB at 10.98 GHz respectively. Incorporation of MWCNT enhanced the thermal stability of the composite which has been confirmed by thermogravimetric analysis.