Tailoring the structural, optical, and electrical properties of PVDF/Ppy/MWCNT nanocomposites through synergistic hybrid reinforcement

Polyvinylidene fluoride (PVDF)-based nanocomposites incorporating polypyrrole (Ppy) and multi-walled carbon nanotubes (MWCNTs) were systematically developed with the objective of enhancing their structural, surface, optical, and electrical characteristics for advanced multifunctional applications. The nanocomposites were developed by a solution mixing and casting method, in which Ppy and MWCNTs were incorporated into the PVDF matrix at different loading i.e., 2, 4, 6, and 10 wt%. The prepared nanocomposite films were systematically characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FESEM), UV-Vis-NIR spectroscopy, and dielectric and impedance measurements to evaluate their structural, morphological, optical and electrical characteristics. XRD analysis revealed a predominantly semi-crystalline structure with increasing amorphous character and controlled crystallite evolution governed by the increased loading of nanofiller. UV-Vis-NIR spectroscopic analysis demonstrated enhanced optical absorption, progressive bandgap narrowing, and increased disorder-induced localized states with increasing MWCNT loading, indicating enhanced electronic interactions. FTIR analysis confirmed strong interfacial interactions between the constituents without significant alteration of their chemical structures. Dielectric and impedance studies confirmed that interfacial polarization dominates at low frequencies, whereas hopping conduction governs the high-frequency response, resulting in enhanced dielectric constant (400 to 1000) and electrical conductivity (1.76 × 10 −5 to 5.46 × 10 −5 ) and reduced impedance with increasing loading of nanofiller. FESEM analysis revealed a heterogeneous yet interconnected morphology, with relatively well-dispersed fillers at 4 wt% facilitating the formation of a partial conductive network. The hybridization of conductive polymer and carbon nanofillers within the PVDF matrix promotes strong interfacial interactions, leading to improved charge transport, interfacial polarization, and formation of efficient conductive networks. Thus, the synergistic effects of Ppy and MWCNTs significantly improved the multifunctional performance of the PVDF-based nanocomposites, demonstrating their potential for applications in flexible electronics, energy-storage devices, and advanced sensing systems.