Targeted synthesis of hydrophobic piperazine‐rich porous organic polymers for radioactive methyl iodide immobilization
Yinhui Li, Tengfei Shi, Yongzheng Wang, Qingkuan Meng, Hedong Yang, Youzhi Wang, Qingxin Liang, Gang Zhang, Heping MaAbstract
Cost‐effective and leakage‐proof capture of volatile radioactive methyl iodide (CH 3 I) from nuclear off‐gas remains challenging. Guided by computational screening, we designed hydrophobic, nitrogen‐rich porous organic polymers (NPOPs) featuring N‐alkyl piperazine/piperidine motifs. The optimized NPOPs achieve record CH 3 I uptake of more than 4 g g −1 with rapid kinetics (>85% saturation within 60 min). Spectroscopic analyses ( 13 C SS‐NMR, XPS, FT‐IR) confirm irreversible chemisorption via N‐methylation as the dominant mechanism. NPOP‐1 exhibits a high dynamic breakthrough capacity of 3.86 g g −1 under simulated operational conditions and retains structural integrity after high‐dose γ‐irradiation. Crucially, in tests with radioactive CH 3 131 I, NPOP‐1 demonstrates a 99.999% retention rate. Kilogram‐scale synthesis yields material at an estimated cost of $1.5 USD g −1 . These attributes establish NPOPs as a viable, economically competitive platform for the safe, permanent sequestration of radioactive organic iodides in nuclear fuel cycle applications.