Structural, physical and optical properties of Bi4.86La1.14O9/PVA thin-film for shielding applications

An innovative lead-free, Bi 4.86 La 1.14 O 9 /polyvinyl alcohol (PVA) nanocomposite (LB-PVA), thin-film was fabricated. The Bi 4.86 La 1.14 O 9 nanofiller, synthesized via sol–gel method, was blended with PVA and crosslinked with citric acid using a coating technique . The nanofiller was characterized by XRD , TEM, zeta potential , and DLS , while the nanocomposite thin-film was analyzed via FTIR, XRD, SEM-EDX, and UV–vis spectroscopy, with comparisons to raw crosslinked PVA. The key physical properties were analyzed: density, OPD, V m , V ∘ , N, R p and R i . The increased V ∘ value opposed the density direction, leading to reduced OD in the LB-PVA thin-film. In addition to mechanical properties (e.g., TS), the optical characteristics including absorbance spectra other properties were systematically investigated. The γ -ray shielding performance (0.015–1.50 MeV) was rigorously evaluated through combined Py-MLBUF and Phy-X/PSD computational quantitative analysis, using LAC , MAC, HVT, and TVT as primary metrics. Their quantified dual computational methods showed excellent agreement with minimal deviation ( < 0.03%). The buildup factors EBF and EABF for single and double layers, along with MFP, Zeff, σ -electron, and σ -atomic were also investigated via Py-MLBUF simulation. The novel LB-PVA composite, with ultralow doping ( ∼ 0.95%), exhibited superior MAC compared to CPVA, attributed to high-Z synergy (La/Bi) and optimal nanoparticle dispersion.