Development of Conducting Filler Based Nanocomposites for Enhanced EMI Shielding Applications

Abstract

The increasing need for efficient, lightweight, and cost-effective electromagnetic interference (EMI) shielding materials has spurred significant research into polymer-based composites. This study presents the development of polyaniline-carbon fiber (PANI-CF) composites, enhanced with poly (3,4 ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), to achieve superior electrical conductivity and shielding performance. The composites were prepared via in-situ polymerization of aniline, incorporating varying concentrations of carbon fiber (2wt% ,5wt%), followed by PEDOT:PSS coating to improve conductivity. Characterization revealed significant improvements in structural, morphological, and functional properties of composites. Fourier transform infrared spectroscopy (FTIR) validated successful chemical interactions between the PANI matrix, CF, and PEDOT:PSS. X-ray diffraction (XRD) analysis confirmed the semi-crystalline structure of PANI and the graphitic nature of CF, with higher CF content enhancing crystallinity. Scanning electron microscopy (SEM) revealed uniform CF dispersion and the formation of smooth, continuous PEDOT:PSS coatings, mitigating filler agglomeration and enhancing electrical pathways. Thermogravimetric analysis (TGA) further highlighted the improved thermal stability, attributed to the dispersion of CF and PEDOT:PSS coating. Electrical measurements shows the shift from semiconducting to ohmic behavior in PANI CF composites, enhanced by filler content and PEDOT:PSS coating, improving charge transport and conductivity. Conductivity measurements demonstrated significant improvement, with the PANI-5%CF-PEDOT:PSS composite achieving the highest conductivity of ~0.012 S/cm. The optimized composites exhibited remarkable conducting properties making it an effective material for EMI shielding. These findings demonstrate the potential of PANI-CF-PEDOT:PSS composites as lightweight, corrosion-resistant, and thermally stable alternatives to conventional EMI shielding materials.