Influence of activated carbon weight concentration on loss parameters of AC/CF composites in X-band

The rise of electronic devices has increased electromagnetic pollution, creating a demand for improved radio-absorbing materials. This study aims to develop microwave-absorbing materials using carbon fibre and biomass-derived activated carbon, with a focus on enhancing their electromagnetic properties for sustainable applications. The effects of incorporating activated carbon into carbon fibre composites at varying weight concentrations have been investigated. A 2mm-thick composite was fabricated and analysed using waveguide measurements. Results indicate that activated carbon significantly alters the structural characteristics of the composites, enhancing graphitisation and increasing amorphous carbon content, thereby improving electrical conductivity and microwave absorption. Increasing the activated carbon content enhances dielectric properties and electromagnetic wave attenuation, with the 10 wt% AC/CF composite achieving a peak electrical conductivity of 0.9 S/m. This composite demonstrates superior microwave absorption performance, particularly in the X-band, with notable improvements in absorption loss, transmission loss, and reflection loss, attributed to enhanced interfacial polarization and scattering effects.