Development of nanocomposites comprising starch and bismuth (III) oxide: An exploration of their viability as substitute materials for shielding high-energy radiation

This research focused on investigating the radiation shielding and thermal characteristics of composite materials created by varying the ratios of Bi₂O₃ and starch. Various composite formulations were developed by blending Bi₂O₃ powder with starch in ratios of 5%, 10%, 15%, 20%, 25%, 30%, 40%, and 50%. Linear attenuation coefficients of these composites were valued using a NaI(Tl) gamma spectrometry system. Additionally, theoretical calculations were performed using the XCOM platform and GAMOS simulation, incorporating fundamental composite analysis, and these results were compared with empirical data. X-ray diffraction analysis revealed distinct diffraction peaks in Bi₂O₃ powder, and its pore size distribution exhibited favorable characteristics. Considering the morphological properties of the nanocomposites, it was observed that Bi₂O₃ in the starch matrix did not undergo agglomeration and even formed homogeneous structures. Examination of the thermal degradation profiles of the samples indicated a significant overlap between the remaining ash quantities and the mass percentages of the prepared samples. The measured experimental linear attenuation coefficient results were ranged from 0.147 ± 0.023 cm⁻¹ to 0.267 ± 0.107 cm⁻¹ for 662 keV, from 0.119 ± 0.007 cm⁻¹ to 0.165 ± 0.021 cm⁻¹ for 1173 keV, and from 0.111 ± 0.015 cm⁻¹ to 0.152 ± 0.040 cm⁻¹ for 1332 keV for starch-Bi₂O₃ nanocomposites. Notably, the most effective shielding material among the studied samples was found to be a combination of starch and 50% Bi₂O₃.