Enhanced Gamma Ray Radiation Resistance of Silicone Elastomers via Trace Addition of Perovskite Nanocrystals for Free Radicals Scavenging.

Halide perovskites exhibit remarkable properties, such as high optical absorption coefficient, excellent defect tolerance, simple and cheap preparation process, etc., especially excellent radiation hardness, which makes them used in high-energy ray radiation environments. Free radicals, with singly occupied molecular orbitals, are highly reactive intermediates that play a critical role in material degradation under ray radiation. However, the interaction between these radicals and halide perovskites remains inadequately understood, despite its crucial for enhancing the γ-ray resistance of elastomers. This study investigates the interfacial charge transfer between halide perovskite nanocrystals (PNCs) and silicon, carbon, and hydrogen radicals, supported by theoretical calculations and electron spin resonance analyses, revealing the immobilization of reactive radicals on the PNC surface. To further investigate, amino-propyl triethoxysilane (APTES)-passivated PNCs are synthesized and incorporated into silicone elastomers via an in situ one-step crosslinking process. Under high-dose γ-ray irradiation, these elastomers generate free radicals that typically degrade the material. PNCs effectively stabilize these radicals, improving the elastomer's γ-ray resistance, with only an 11% loss in mechanical strength after 300 KGy, one-fifth of the loss in unmodified silicones elastomers. This study provides valuable insights for developing radiation-resistant perovskite polymer composites for aerospace and nuclear industries.