Effect of blue light irradiation on the formation of silver nanostructures in polyvinyl alcohol nanocomposite films

PVA/AgNO₃ composite films were prepared on fused silica substrates using a casting technique and irradiated with blue light to synthesize silver nanoparticles (AgNPs) within the polymer matrix. The physical and chemical properties of the films were analyzed, revealing increased crystallinity and the formation of Ag nanoparticles and nanorods after irradiation. FTIR spectra showed a vibrational band of Ag–O at 760 cm⁻¹ after 30 min of irradiation. The absorption coefficient exhibited a transition band between 400 and 500 nm, with peak amplitude increasing with irradiation time, indicating more Ag nanostructure formation. Differential scanning calorimetry (DSC) analysis showed a rise in melting temperature from 62 to 84 °C and a decrease in crystallization temperature from 188 to 185 °C. Thermogravimetric analysis (TGA) indicated thermal stability with minor mass loss up to 270 °C. Electrical conductivity increased from 2.29 to 3.35 µS.cm⁻¹ with increased blue light irradiation time. Our study documents the efficient synthesis of well-distributed AgNPs within the PVA matrix using blue light irradiation, which significantly enhances the optical, thermal, and electrical properties of the composite films. These improved properties make the films suitable for applications in sensors, flexible electronics, and antimicrobial coatings.