Newly developed CeO2 and Gd2O3-reinforced borosilicate glasses from municipal waste ash and their optical, structural, and gamma-ray shielding properties.

From the useless municipal solid waste (MSW) ashes, CeO2, Gd2O3 and CeO2 + Gd2O3 doped borosilicate glasses were organized via melting-quenching procedure. Various optical, structural, physical and radiation shielding parameters were examined towards the influence of 100 kGy of γ-radiation. UV-visible NIR spectra revealed UV peaks at 351, 348 and 370 nm corresponding to the trivalent states of Ce3+ and Gd3+ ions, while, photoluminescence (PL) spectra displayed asymmetric broad excitations of Ce3+ and Gd3+ ions due to 4f → 5d transitions, and emission intense bands at 412, 434, and 417 nm. CIE chromaticity shows that Gd3+ ions increase the luminescence of Ce3+. FTIR absorption bands revealed an overlapping between tetrahedral groups of silicate (SiO4), with trigonal (BO3) and tetrahedral (BO4) units of borate. The influence of 100 kGy obtains quite reduction in UV-visible NIR and PL peaks, large stability in FTIR and ESR spectra, and stability of thermal expansion coefficient (CTE) as well. The whole data revealed optical, structural and physical stability of glasses after irradiation besides an enhancement in microhardness owing to more structural compactness and high bonding connectivity. Radiation shielding parameters from Phy-X/PSD program showed higher values of mass (MAC) and linear attenuation coefficients (LAC), and effective atomic number (Zeff) in the order of; glass Ce+Gd > glass Ce > glass Gd. Ce + Gd doped glass revealed also the lowest half value layer (HVL) comparing to other shielding commercial concretes. The study recommends the beneficial and economical use of the useless MSW ash to produce CeO2 and/or Gd2O3 borosilicate glasses with hopeful radiation shielding features.

Fabrication and characterization of different PbO borate glass systems as radiation-shielding containers.

Three borate glasses of 50, 35, and 15 mol% PbO-doped Ce, Sb, or Mn ions were fabricated via the melting-annealing procedure. Their structural features were inspected before and after 250 kGy of gamma irradiation using FTIR and ESR techniques. The spectra of the ESR and FTIR vibrational bands remain constant, with a minor reduction in N4 and an enhancement in density values after irradiation, indicating the large structural stability and glass compactness. Many radiation shielding parameters were studied, such as gamma dose rate (µSv/h), dose transmission %, lifetime cancer risk %, macroscopic effective removal cross-section (∑R), mass stopping power, and projected range values ​​were considered for protons particles by SRIM Monte Carlo simulation code and ESTAR program. The whole data reveals the high radiation shielding efficiency of the glasses compared to other standard shields to be used as glass immobilizers for radioactive wastes or storage containers, e.g., for nuclear medicine units in hospitals.