Janus Dual Self‐Strengthening Structure of Bi₂O₃/Gd₂O₃ Nanofibrous Membranes for Superior X‐Ray Shielding

Abstract

Bi2O3/rare earth oxide biphasic absorbers are attractive for high‐efficiency X‐ray shielding due to the complementary X‐ray absorption effects. However, its application is severely hindered by poor interphasic contact. Here, a new Janus interface engineering strategy is reported for the construction of continuous and flexible Bi2O3/Gd2O3 crystal nanofibrous membranes (FJNMs) with micro/nano dual self‐strengthening interphasic adhesion. This strategy facilitates online micro‐interlocking between Bi2O3/Gd2O3 nanofibers and in situ nano‐grain fusion between Bi2O3/Gd2O3 crystals, significantly enhancing the adhesive strength at the Bi2O3/Gd2O3 interface. Additionally, the synergistic shielding effect from Bi2O3/Gd2O3 absorption and multiple reflections in Bi2O3 and Gd2O3 crystal lattices make the nanofibrous membranes a superior X‐ray radiation barrier. The FJNMs demonstrate integrated features of exceptional X‐ray shielding efficiency (91%–100%), robust interfacial adhesion (lap‐shear strength >3.8 MPa), prominent flexibility, lightweight, and outstanding breathability. The design concepts of fibrosing biphasic absorber assemblies pave the way for asymmetrically assembling biphasic materials, setting the stage for a fundamental shift in next‐generation radiation shielding materials.

Bi2O3/Gd2O3 Meta-Aerogel with Leaf-Inspired Nanotrap Array Enables Efficient X-Ray Absorption

“…Consequently, metal oxides incorporating high-Z elements such as bismuth oxide (Bi 2 O 3 ), tungsten oxide (WO 3 ), and copper oxide (CuO) have been extensively investigated and documented as viable substitutes for Pb in recent decades. Bi 2 O 3 , with its high Z-value (83), thermal stability, biocompatibility, low toxicity, and minimal environmental impact, has emerged as the most promising candidate material. − Researchers have found that, when the X-ray energy closely matches the binding energy of the K -shell or L -shell electrons of the atom, known as the K / L absorption edge, resonance absorption occurs; therefore shielding efficiency sharply increases. − The L absorption edge of Bi 2 O 3 is near 13 keV, and the K absorption edge is near 90 keV, which has a strong absorption effect for X-rays larger than 13 and 90 keV, but a weak X-ray absorption region in the energy range of 40–90 keV. Achieving high shielding efficiency for a single-component element across the 0–90 keV range is extremely challenging, if not impossible, due to the presence of absorption edges for each element.…”