Structure–Property Relationships in Flexible PVA /Polypyrrole Films: Optical and Dielectric Spectroscopy for Optoelectronic and Energy‐Storage Applications
Abstract
Polyvinyl alcohol/polypyrrole (PVA/PPy) blend films with varying PPy loadings (0, 1, 3, and 5 wt%) were produced via solution‐casting method. The impact of PPy inclusion on structural, optical, dielectric, and electrical properties of fabricated films was examined. Structural investigations showed that PPy interacted successfully with the PVA matrix, reducing crystallinity and forming robust interfacial contacts (corroborated by FTIR and XRD). PPy was uniformly distributed inside hosting matrix, forming conductive channels at higher loading. Optical investigations revealed a notable increase in absorbance, a reduction in the direct optical bandgap (from 5.25 to 4.85 eV) and an increase in Urbach energy (from 1.67 to 2.40 eV), indicating enhanced localized states and structural disorder. Dielectric studies showed an increase in dielectric constant with increasing PPy content (from 1.98 to 10.9), accompanied by improved interfacial polarization and charge‐storage capacity. Analysis of electrical modulus and impedance confirmed accelerated relaxation dynamics and decreased bulk resistance (from 3.8 × 10 10 to 0.9 × 10 10 Ω), accompanied by enhanced charge transport. AC conductivity and discharged energy density increased significantly with PPy loading (from ∼8.8 × 10 −6 to 4.80 × 10 −5 J m −3 ). The results indicate that incorporating PPy effectively modifies PVA' properties, supporting its use in optoelectronics and energy‐storage systems.