Green lightweight lead-free Gd₂O₃/epoxy nanocomposites with outstanding X-ray attenuation performance

This work describes the design, preparation, and characterization of an environmentally friendly, clinically safe, and lightweight Gd₂O₃/epoxy nanocomposite (Gd nanocomposite) that can provide an alternative to traditional toxic lead (Pb)-based materials for diagnostic X-ray protection. Based on the effect of inter-particle forces, the adsorption of sodium dodecyl sulphate (SDS) surfactant on the surface of ultrafine ball milled Gd₂O₃ reduces the agglomeration and aggregation in nanoparticle preparation and dispersion in the polymer matrix, thereby improving the attenuation properties of this material per unit area. While an 8 mm-thick Gd nanocomposite with volume fractions (ϕ_s) of 0.10, 0.12, and 0.14 can reduce transmitted X-ray intensity by about 93–99%, a 16 mm composite thickness (ϕ_s = 0.12) can achieve more than 99% protection in the energy range 60–120 kVp. These specimens show comparable attenuation efficiency with the pure lead sheets of 0.25, 0.35, 0.5, and 1 mm thickness that are standardly used in radiology protection. The mass of the Gd nanocomposite (ϕ_s = 0.14, 8 mm thickness) X-ray protection screen needed is significantly lighter than that made from concrete, glass, and wood at the same attenuation performance (97–99% attenuation). The synthesized material also introduced in this article, with 36–48% less weight, shows better attenuation proficiency than three other lightweight commercial non-Pb composite products above 73 kVp. The X-ray attenuation efficiency per unit area mass of the Gd composite with ϕ_s of 0.1 attained the highest value of ∼0.88 (cm²/g) which is equal to that of pure Pb. This work proposes a way to produce an environmentally safe, lightweight composite with prominent X-ray attenuation properties.