Amide-Linked cis,cis-1,3,5-Cyclohexanetricarbonyl-Based Porous Organic Polymers for the Uptake of Iodine in Solution and Vapor Phase

Radioactive iodine pollution from nuclear waste poses a major threat to both the environment and human health. Therefore, capturing and storing radioactive iodine are of paramount significance. Herein, three amide-linked porous organic polymers (POPs), viz., CD-POP, PD-POP, and BD-POP were synthesized for the uptake of iodine in solution and vapor phases. The amide-linked POPs were prepared by the polycondensation of cis, cis -1,3,5-cyclohexanetricarbonyl chloride with trans -1,4-cyclohexanediamine, p -phenylenediamine, and benzidine, respectively. To the best of our knowledge, this is the first report for iodine uptake by amide-based POPs. PD-POP, CD-POP, and BD-POP were found to be efficient for the capture of iodine in the vapor phase showing an uptake capacity of 3.53, 2.60, and 0.84 g·g –1, respectively, at 75 °C. Furthermore, for the removal of iodine from the cyclohexane solution, they exhibited uptake capacities of 297, 286, and 248 mg·g –1 for PD-POP, CD-POP, and BD-POP, respectively. These thermally robust, insoluble amide-based polymers have shown impressive recycling capabilities, with performance maintained for at least five cycles without a significant decrease in the adsorption capacity.