Defect-engineered Ce-MOFs: Synergistic radical scavenging and mechanical reinforcement for gamma radiation-resistant epoxy composites

In this study, a novel Ce metal–organic framework (Ce-MOF) material was successfully synthesised via structural defect engineering using 5-hydroxyisophthalic acid as a defect agent by precisely controlling the Ce³⁺/Ce⁴⁺ valence ratio and hydroxyl content. Experimental results demonstrated that Ce-MOF not only effectively scavenged the free radicals generated in epoxy resin (EP) during γ-irradiation through the synergistic interaction between hydroxyl defects and Ce, thereby reducing the radical-induced chain scission and considerably enhancing the γ-radiation resistance of EP, but also improved the mechanical properties and thermal stability of EP via chemical bonding and hydrogen bonding. The oxidation inhibition rate improved from −34.2 % for pure EP to −6.2 % for EP/Ce-MOF-OH3. Furthermore, the material maintained high tensile strength and fracture toughness even after irradiation, exhibiting excellent radiation stability. After exposure to 800 kGy of γ-radiation, the changes in tensile strength and fracture toughness of pure EP were −23.05 % and −24.07 %, respectively, while the changes in those of EP/Ce-MOF-OH3 were only −9.75 % and −5.39 %, respectively. This study provides a new strategy for developing advanced radiation-resistant materials with considerable application potential.