Impedance Analysis and Dielectric Performance of Microwave-Assisted Synthesized MWCNT/Polystyrene Nanocomposites: Influence of Microwave Power

This study investigated the enhancement of dielectric properties in multiwalled carbon nanotube (MWCNT)/polystyrene (PS) nanocomposites for potential applications in embedded capacitors. The synthesis of MWCNT/PS nanocomposites was achieved using microwave-assisted in situ polymerization. To provide an exact comparative analysis, a heat-assisted synthesized nanocomposite was also prepared alongside the microwave-assisted samples. This unique feature of this research lies in its comprehensive exploration of how microwave power can affect the morphology, electrical properties, and dielectric characteristics of nanocomposites. In the heat-assisted sample, the MWCNTs lacked a polystyrene layer, and the presence of polymer aggregates was evident, which may be attributed to the random initiation sites for the polymerization reaction in the MWCNT/PS mixture. The microwave-assisted synthesized nanocomposites exhibit a decrease in AC conductivity as the microwave power increases. This is accompanied by an increase in both the real and imaginary impedance. These changes can be attributed to the higher polystyrene content in the nanocomposites, which results in a decrease in conductive pathways. Moreover, the real permittivity decreases as the microwave power increases due to the reduced availability of individual MWCNTs. The observed linear trend in the imaginary permittivity within the low-frequency region underscores the influence of DC conductivity, while the electric modulus analysis highlights the dominance of DC conduction and the absence of relaxation peaks attributable to high conductivity. This study significantly advances the understanding of microwave power's effect on the electrical properties of MWCNT/PS nanocomposites, thereby illuminating their potential applications across various fields.