X-ray attenuation and dielectric response of MnFe2O4/NiO@PVA/PEG films within the medical diagnostic X-ray range

Lead aprons remain standard in diagnostic radiology despite their weight and toxicity. In this study, PVA/PEG films containing 15.52 wt% MnFe2O4/NiO nanocomposite were prepared by solution casting and compared with the undoped blend. The films were evaluated by XRD, TEM/SEM, TGA, dielectric spectroscopy, and experimental X-ray attenuation measurements. TEM showed semispherical MnFe2O4/NiO particles with an average size of 45.79 nm. XRD gave smaller crystallite sizes of approximately 16.5–16.8 nm, indicating that individual particles may contain several coherently diffracting domains. The PVA/PEG blend was semicrystalline, with features at 2θ = 19.47° and 23.30°, and its crystallinity fell from 34.70% to 28.41% after nanocomposite incorporation. TGA showed lower mass loss in the filled film, which retained 14.12% residue at 800 °C. The dielectric constant rose from 194 to 253 at 5 kHz and from 22 to 79 at 2 MHz, while high-frequency loss decreased. The linear attenuation coefficient rose from 0.0181 to 0.0639 cm −1 at 50 kVp and from 0.0105 to 0.0653 at 70 kVp. At 90 and 120 kVp it rose from 0.0114 to 0.0494 and from 0.0094 to 0.0314 cm −1 . Expressed as mass attenuation coefficient these are gains of 226.0%, 473.6%, 299.9% and 210.0%. At 50 kVp, the HVL decreased from 38.28 to 10.86 cm and the radiation protection efficiency increased from 1.32% to 4.62%. However, the absolute shielding efficiency remained below 5% at this filler loading. These results indicate the potential of the film as a lead-free material with both dielectric and X-ray attenuation properties.