Chelation-immobilized gadolinium and dynamic crosslinking enable high-efficiency nuclear radiation shielding polymers

Conventional polymeric radiation shielding materials suffer from filler aggregation, weak interfacial bonding, and metal leaching. This work presents a chelation immobilization strategy that enables quantitative grafting of high atomic number metals, addressing these challenges. Gadolinium complexes with a macrocyclic ligand derivative are covalently grafted onto polymer chains through click chemistry, producing stable radiation shielding polymers. Importantly, coordination between gadolinium and the ligand induces electron rearrangement, forming multiple hydrogen bonds that act as reversible dynamic crosslinking points. Under mechanical forces, these hydrogen bonds break and rebuild, dissipating energy while enhancing both strength and ductility, overcoming the trade-off between strength and toughness. The polymer exhibits strong attenuation of X and gamma rays and thermal neutrons at low metal loading and remains stable over a wide range of acidity and temperature. The dynamic crosslinked structure also provides good processability and reusability. This study resolves the conflict between high shielding efficiency and lightweight flexibility, offering a route for next generation transparent, lightweight, and wearable nuclear radiation shielding materials. Polymer radiation shields suffer from poor dispersion and metal leaching. Here, the authors developed a dynamically crosslinked gadolinium-grafted polymer that combines high radiation shielding, mechanical toughness, flexibility, and reusability.