Fabrication of cobalt filled multi-walled carbon nanotubes/polyurethane composite for microwave absorption

Abstract

This research work describes the design and method of development of microwave absorber. This study was conducted for analysis of reflection loss performance with the magnetic modifications of Multi-Walled Carbon Nanotubes (MWCNTs). Cobalt filled Multi-Walled Carbon Nanotubes composites were prepared by three step method. Composites were developed with varying weight percentage of Cobalt Sulphate and Multi-Walled Carbon Nanotubes. The morphology, elementary analysis and absorbing properties of Cobalt filled Multi-Walled Carbon Nanotubes composites were studied by FESEM, EDX and Vector Network Analyzer. The maximum reflection loss is observed for (50% MWCNT and 50% Cobalt Sulphate) is −30.22 dB at 11.8 GHz and the maximum bandwidth window is available for (40% MWCNT and 60% Cobalt Sulphate) is 3.9 GHz in the frequency range of 8–13 GHz with 3 mm thickness, which can be credited to synergistic effect of improved matched impedance and greater microwave attenuation properties of the absorber. The combined usage of dielectric loss and magnetic loss absorber design shows great diversity and can be a promising candidate for designing high performance microwave absorbing materials.