Gamma irradiation-induced modifications in structural and dielectric behavior of hydrofluoric acid-etched PVA/SiO ₂ /Ag nanocomposites

The etching of polymer surfaces has attracted considerable attention among polymer scientists and engineers owing to its wide range of applications in electronics and photovoltaic devices. In this work, the synergistic effects of HF etching and γ-irradiation at different doses (15, 25, and 35 kGy) on the structural and dielectric properties of PVA/SiO 2 /Ag nanocomposites are systematically investigated. The chemical structure of the nanocomposites was analysed using Fourier transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) results revealed an enhancement in the amorphous regions of the nanocomposites upon irradiation at 15 and 35 kGy. Scanning electron microscopy (SEM) images revealed a porous surface morphology, with pore size strongly dependent on the applied irradiation dose. The dielectric properties were found to be highly sensitive to γ-radiation exposure. Among all samples, the HF/PVA/SiO 2 /Ag nanocomposite irradiated at 15 kGy exhibited the highest AC conductivity (σ ac ), dielectric constant, and dielectric loss. Quantitatively, this sample showed a maximum concluded DC conductivity (σ dc ) of 1.76 × 10 −6 S·cm −1 , which is approximately one order of magnitude higher than that of the unirradiated composite (1.84 × 10 −7 S·cm −1 ). This enhancement is attributed to increased amorphous content and improved charge carrier mobility, facilitating more efficient hopping conduction pathways. In contrast, the sample irradiated at 25 kGy displayed a significant reduction in electrical performance, indicating that excessive irradiation may induce radiation-induced crosslinking. These findings demonstrate that γ-irradiation is an effective and controllable approach for tailoring the structural and dielectric properties of etched polymer nanocomposites, making them promising candidates for applications in energy storage, radio-frequency devices, and optoelectronics.