Tough, self-healing, and freeze-resistant composite dual-network hydrogels for the decontamination of surface uranium (Ⅵ)

Abstract

Hydrogels have attracted widespread attention in the field of surface radioactivity decontamination due to their mild and rapid decontamination processes, as well as their tunable properties. However, fabricating decontamination hydrogels with suitable mechanical properties and environmental adaptability remains challenging. In this study, a tough and freeze-resistant hydrogel (PEAG) was prepared based on graphene oxide (GO), polyvinyl alcohol (PVA), agar (AG), and ethylene glycol (EG) for efficient removal of surface radioactive uranium (VI). Due to the dynamic action of borax and the formation of a nanocomposite dual-network structure, PEAG possesses improved modulus and excellent self-healing properties, allowing the hydrogel to be easily applied to surfaces and to perform operations such as stretching and peeling. In addition, it is found that the PEAG achieves excellent decontamination rates for radioactive uranium (VI) on glass (88.53±1.43 %), stainless steel (86.72±3.41 %), rubber (67.0±2.43 %), ceramics (82.39±1.78 %), and cement (64.52±1.72 %) surfaces, respectively. XPS and contact angle experiments demonstrated that the improved decontamination performance of PEAG is mainly due to the abundant hydroxyl and carbonyl functional groups in the graphene oxide adsorbent, which provide a rich source of complexation sites and enhance its hydrophilic properties for PEAG. Additionally, due to the incorporation of EG, the PEAG hydrogel exhibits good environmental adaptability, which can retain internal moisture and maintain softness and decontamination stability at low temperatures of −20°C. Therefore, PEAG hydrogel is a promising and sustainable candidate material for various surface radioactive decontamination scenarios.