Mussel-inspired structure based CsPbBr3/Aramid nanofiber composite film for lightweight, flexible and superior X-ray shielding

Abstract

Excessive exposure to X-rays risks human health and the proper functioning of precision instruments. Conventional materials have high atomic numbers, but their unsatisfactory mechanical properties hinder commercial application. Currently, X-ray shielding materials must fulfill the characteristics of high strength, lightweight, flexibility, high shielding efficiency, and low secondary radiation to alleviate urgent radiation risks. Here, this work introduces a mussel-inspired structure into the construction of the lightweight and flexible CsPbBr3/aramid nanofiber (ANF) composite films to enhance the ability of X-ray absorption. The CsPbBr3 provides effective X-ray shielding in millimeter thickness and addresses the challenge of absorption zone matching by containing both Cs and Pb elements. The interlayer reflection caused by the mussel-inspired structure increases the photon travel distance in the film, which synergizes with the absorption of X-rays by the elements, significantly improving shielding performance and weakening secondary radiation. The CsPbBr3/ANF composite film with 60 wt% CsPbBr3 content demonstrates robust tensile stress (57.6 MPa), lightweight (0.87 g/cm3), superior heat resistance, exceptional flexibility with a notable mass attenuation coefficient (58.2–65.6 cm2/g in the 20–70 kV range), which is much higher than Pb plate. Considering its comprehensive performance advantages, the CsPbBr3/ANF composite film significantly impacts the landscape of X-ray shielding.