Enhanced Dielectric and Electromagnetic Interference Shielding Properties of Ag-PANI/BC Ternary Nanocomposites at Room Temperature

Abstract

In this work, green tea extract and banana peels, natural ingredients, were used in the synthesis of silver-PANI/banana carbon (Ag-PANI/BC) ternary composites. In situ chemical polymerization method was adopted with incorporating varied weight percentage composition of banana peel derived carbon. The formation of the composite was confirmed by FTIR spectroscopic analysis, where the characteristic vibrational frequency bands confirmed the successful interaction and integration within the 8 wt.% Ag-PANI/BC ternary composite. The amorphous nature of PANI and Ag–PANI, as well as the semicrystalline structure of the Ag–PANI/BC ternary composite, were confirmed through powder X-ray diffraction (pXRD) analysis. Surface morphology observed from SEM images of the Ag–PANI/BC (8 wt.%) composite revealed granular, non-uniform, spherical-like structures with inhomogeneous surfaces, ranging in size from approximately 90 to 175 nm. The composite shown comparable AC conductivity 10^–6 to 10^–4 S/cm for 6, 8, & 10 wt.% composites measured in the frequency range 20 Hz to 10 MHz. The dielectric constant and tangent loss measurements indicate that the ternary composites are the promising candidates for energy storage applications operating at a frequency of 1000 Hz. Significantly, the 6 wt.% and 8 wt.% Ag–PANI/BC composites exhibited excellent electromagnetic interference (EMI) shielding effectiveness, achieving values of approximately 25-26 dB in the S-band (2.1-3.0 GHz), demonstrating their suitability for practical applications in electronic and electrical devices operating within this frequency range.