Browsing by Author "البجادي, ريهام"

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Open Access
Study of the Optimal Concentration of Nitro Blue Tetrazolium dye in PVA Films to Improve Radiation Dosimetry Performance
(Qassim University, 2024) البجادي, ريهام; العشرة, صالح
This study aimed to develop a nanocomposite film based on polyvinyl alcohol (PVA) polymer and nitro blue tetrazolium (NBT) dye as a measure of radiation dose. Films were produced using varying concentrations of (NBT) dye, ranging from 0.015 g to 0.3 g, to identify the optimal concentration for maximum dosimetric efficiency. The study focused on the effects of low doses of radiation commonly used in medical radiological diagnostics within a range of a few milligrays (mGy). The films were exposed to X-rays at low doses ranging from 20 to 100 mGy, and some were subjected to low doses of gamma rays emitted from three Cs-137 sources, with doses of 8, 25, 55, and 96 mGy. As the concentration of the NBT dye increased, the films displayed a more pronounced yellow tint. After exposure to radiation, the films turned a yellowish-brown color, which became more intense with higher doses. Furthermore, the PVA/NBT films showed good stability when stored in the dark for up to 30 days after exposure to radiation. The films underwent assessment by analyzing their UV-visible absorption spectra, which exhibited a peak at 376 nm. Subsequent exposure to X-rays resulted in a spectral shift to 384 nm. Additionally, the relative density of the red channel was examined using ImageJ software, which demonstrated a linear increase with increasing doses and NBT dye concentration. The preparation method was validated by XRF analysis, and the solubility of the NBT salt was excellent, with an R2 value of 0.9656. The sensitivity of the films was evaluated through XRD analysis, which indicated that structural rearrangements occurred at increasing radiation doses, particularly evident at high NBT concentrations. Moreover, SEM analysis supported this change as exposure to elevated radiation doses resulted in significant morphological alterations in PVA/NBT films, leading to shapes that resemble torn tree trunks with an increased concentration of NBT. The spectrocolorimetric study results showed that the different CIEL*a*b* coordinates, as well as the total color difference (〖∆E〗_ab^*) and color strength (K/S), were directly proportional to the intensity of the applied dose following the increase in the NBT concentration. Finally, the optimal concentration of NBT was determined based on the changes in color and chemical structure of the films following exposure to gamma and X-ray radiation. Overall, the PVA/NBT dosimeter could offer a promising and efficient alternative for the prompt and accurate detection of low gamma and X-ray doses in diagnostic radiology.
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