Functionalized Ionic Porous Organic Polymers Exhibiting High Iodine Uptake from Both the Vapor and Aqueous Medium

Large-scale generation of radioactive iodine (I-129, I-131) in nuclear power plants pose a critical threat in the event of fallout, thus rendering the development of iodine sequestering materials (from both the vapor and aqueous medium) highly pivotal. Herein, we report two chemically stable ionic polymers containing multiple binding sites, including phenyl rings, imidazolium cations, and bromide anions, which in synergy promote adsorption of iodine/triiodide anions. In brief, exceptional iodine uptake (from the vapor phase) was observed at nuclear fuel reprocessing conditions. Furthermore, the ionic nature propelled removal of >99% of I-3(-) from water within 30 min. Additionally, benchmark uptake capacities, as well as unprecedented selectivity, were observed for I-3(-) anions. The excellent affinity (distribution coefficient, similar to 10(5) mL/g) enabled iodine capture from seawater-spiked samples. Moreover, iodine-loaded compounds showed conductivity (10(-4) S/cm, 10(-6) S/cm), placing them among the best known conducting porous organic polymers. Lastly, DFT studies unveiled key insights in coherence with the experimental findings.

Automated summary

This study reports two chemically stable ionic polymers with multiple binding sites, which show exceptional iodine uptake and efficient removal of I-3(-) from water. These compounds exhibit high affinity, unprecedented selectivity, and conductivity, making them suitable for iodine capture from seawater. Additionally, DFT studies provide key insights consistent with experimental findings.