Eco‐Friendly Mechanochemical Engineering of Poly( o ‐toluidine)/Nb 2 O 5 Composites With Improved Electrical, Dielectric, and Antibacterial Properties

Solvent‐free mechanochemical grinding has emerged as an efficient, scalable, and environmentally benign technique for fabricating conducting polymer composites, providing simple processing, low cost, and minimal environmental impact. In the present work, poly(o‐toluidine) (POT)/niobium pentoxide (Nb 2 O 5 ) composites were successfully prepared through facile solvent‐free mechanochemical mixing. The effects of Nb 2 O 5 inclusion on the structural, optical, morphological, dielectric, electrical, and antibacterial characteristics of POT was comprehensively explored. FTIR analysis confirmed the attachment of the filler to POT through strong polymer‐filler interactions. UV–Vis spectroscopy revealed enhanced optical properties, as evidenced by an increased refractive index and a reduction in the bandgap with increasing Nb 2 O 5 loading. XRD analysis validated the presence of Nb 2 O 5 crystalline phases in the POT matrix, while FE‐SEM analysis demonstrated uniform filler dispersion, with the 15 wt.% composite showing the most homogeneous morphology. Studies on dielectric behavior and AC conductivity indicated that higher Nb 2 O 5 loadings resulted in improved charge transport and polarization. The POT/15 wt.% Nb 2 O 5 composite exhibited the highest dielectric constant and AC conductivity, illustrating the synergistic effect of optimal filler loading on electrical performance. Furthermore, the composites displayed significant antimicrobial activity against Escherichia coli . The solvent‐free fabrication process and multifunctional properties highlight the potential of POT/Nb 2 O 5 composites for advanced optoelectronic devices.