Microwave absorption properties of polyaniline (PAni) with various amount of carbonaceous material (CM)

This study investigates the microwave absorption properties of polyaniline (PAni) with varying carbonaceous material, CM (Fullerene,C60) contents. PAni nanocomposites were prepared with varying contents of C60 ranging from 5 to 40% through a chemical oxidation method by using carboxylic acid as the dopant. The functional groups of PAni nanocomposites were validated by Fourier Transform Infrared Spectroscopy (FTIR) and Ultraviolet–visible (UV–Vis) Spectroscopy analyses. The surface morphology of nanocomposites and the presence of titanium dioxide (TiO2) and C60 were confirmed by Field Emission Scanning Electron Microscopy (FESEM) and X-ray Diffractometry (XRD), respectively. Microwave absorption studies were carried out using Microwave Vector Network Analyzer (MVNA) from 0.5 to 18.0 GHz. The study showed that PAni nanocomposites with 10% of C60 formed the nanorods/nanotubes with the biggest diameter of 200 nm as compared to other PAni nanocomposites. It was found that PAni nanocomposites with 10% C60 also recorded the highest electrical conductivity and relative permittivity of 1.708 × 10–1 S/cm and 9.97, respectively. The nanocomposite that was formulated with 10% of C60 showed an improvement of interchain and intrachain charge transfer as well as molecular polarization along the PAni backbone. Hence, it eventually reduces the electrical energy dissipated by PAni, and finally enhances the microwave absorption properties with the highest reflection loss (RL) of −61.3 dB at 9 GHz.