Enhanced Dielectric Properties of PMMA Polymer Matrix using Conductive Filler CB, CNT and AgNPs

This study investigates the enhancement of PMMA’s dielectric properties through the incorporation of three distinct conductive fillers-carbon black (CB), carbon nanotubes (CNT), and silver nanoparticles (AgNPs), at various weight percentages. The composites were characterized for their real permittivity and dielectric constant across the S, C, and X frequency bands (2–12 GHz) using a Vector Network Analyzer. The results reveal that CB significantly outperformed CNT and AgNPs, achieving a 311% improvement in dielectric constant at 6 GHz with 5.0 wt.% loading. CNT demonstrated moderate enhancements, while AgNPs showed the least improvement, attributed to larger interparticle distances and weaker interfacial polarization. FESEM analysis confirmed the morphological differences between fillers and highlighted the critical role of dispersion and interfacial interactions in determining dielectric performance. This study not only identifies CB as a superior filler for dielectric enhancement but also provides critical insights into the filler-matrix interaction mechanisms. These findings open new avenues for the development of advanced polymer composites tailored for high-performance applications such as energy-efficient capacitors, electromagnetic shielding, and next-generation electronic components.