High-efficiency, flexibility and lead-free X-ray shielding multilayered polymer composites: layered structure design and shielding mechanism

Abstract

To overcome the severe toxicity and blind absorption zone of conventional lead-based shielding materials for X-rays in the 70–90 keV range, the lead-free multilayered polymer composites were designed and fabricated. The effects of the direction of incidence of the X-rays and number of layers as well as layer thickness ratio of the (tungsten/ethylene-octene copolymer)/(bismuth/ethylene-octene copolymer) layered composites on their shielding efficiency were studied systematically. Compared to the traditional polymer blending, the multilayered polymer composites exhibited the improved photon attenuation. The multilayered polymer composites (layer thickness ratio was 3:7) with 6 layers had the best X-ray shielding ability. Moreover, the X-ray shielding provided by the multi-layered interfaces and the multiple complementary effect of the absorption within the multilayered structure were firstly proposed based on computer simulations. The multilayered structural design effectively weakened the probability of the X-ray penetration. Therefore, the X-ray shielding capability can be effectively enhanced through increasing number of layers and the synergistic effect of multi-layered interfaces. The experimental results of this study can serve as guidelines for the fabrication of flexibility, lead-free, lightweight and high-efficiency X-ray shielding materials.

Lightweight Bismuth Titanate (Bi4Ti3O12) Nanoparticle-Epoxy Composite for Advanced Lead-Free X-ray Radiation Shielding

“…Therefore, the less surface roughness (good dispersion of the particles in a polymer matrix) of the prepared composite corroborated well with the X-ray attenuation performance. Moreover, the D-65BTO-ER composite (highest density at 2.2 ± 0.1 g/cm 3 ) with a thickness of 2145 ± 1 μm (∼2 mm) demonstrated almost the same μ/ρ values (8.1 ± 0.3 and 6.2 ± 0.2 cm 2 /g, respectively) as the 50BTO-ER composite at both X-ray energies, which revealed that the ability of X-ray attenuation (at 80 and 100 kVp) mainly depended on (1) the dispersion of the fillers (BTO particles) in a polymer matrix (2) the density and (3) thickness of the shielding materials due to the dominant photoelectric effect at a low X-ray energy. ,, …”

“…Moreover, the D-65BTO-ER composite (highest density at 2.2 ± 0.1 g/cm 3 ) with a thickness of 2145 ± 1 μm (∼2 mm) demonstrated almost the same μ/ρ values (8.1 ± 0.3 and 6.2 ± 0.2 cm 2 /g, respectively) as the 50BTO-ER composite at both X-ray energies, which revealed that the ability of X-ray attenuation (at 80 and 100 kVp) mainly depended on (1) the dispersion of the fillers (BTO particles) in a polymer matrix (2) the density and (3) thickness of the shielding materials due to the dominant photoelectric effect at a low X-ray energy. 22,47,48 Further comparison between D-65BTO-ER and the 0.44 mm Pb sheet showed that the μ/ρ value of the D-65BTO-ER film was slightly lower than that of the 0.44 mm Pb sheet (9.5 and 7.3 cm 2 /g, respectively) at both energies of 80 and 100 kVp, thus indicating that the D-65BTO-ER film displayed comparable X-ray attenuation ability with the 0.44 mm Pb sheet. The mechanism related to the enhanced X-ray attenuation capacity of the prepared composites using BTO particles (BTO structure shown in Figure 1a) dispersed in the epoxy matrix can be attributed to several factors.…”

Assessment of new composites containing polyamide-6 and lead monoxide as shields against ionizing photonic radiation based on computational and experimental methods

“…To understand the shielding effect of composites against ionizing photons (X- and gamma rays), previous studies have addressed possible interactions of photons colliding with shielding materials 53 , 54 . To illustrate the shielding mechanism, one of the samples containing lead filler (PA6/PbO-20%) was selected in the present study, and its possible interactions were investigated by exhibiting the partial (including coherent, Compton, photoelectric, and pair production) and total mass attenuation coefficients in the selected energy range energies (0.001–10 MeV) 39 , and the outcomes are plotted in Fig.…”

Graphene and Hexagonal Boron Nitride in Molybdenum Disulfide/Epoxy Composites for Significant X-ray Shielding Enhancement

“…Electromagnetic radiation (X-ray) is widely applied to many nondestructive materials testing, including medical radiotherapy, medical diagnosis, and geological exploration. 1 Unfortunately, carcinogenic hazards caused by X-ray have been recognized by the International Committee on Radiological Protection, and thus the use of X-ray protective apparel is of great importance to practitioners. 2 The mechanism of Xray attenuation is mainly based on the probability of photoelectric and Compton scattering effects between the incident photons and shielding materials.…”