Novel non-planar piperazine-based organic porous polymer for efficient iodine capture

Iodine fission products with high radioactivity generated in the nuclear fuel fission process usually exist in the form of two isotopes, 131I and 129I. Since radioactive iodine is difficult to be effectively disposed of in the natural physical environment, it is imperative to formulate effective coping strategies to ensure the safe use of nuclear technology. Compared with other solid iodine adsorbents, porous organic polymers (POPs) have shown satisfactory results in terms of capture capability per unit mass and reusable due to their low density and high porosity. In view of this, this study adopted the Schiff base condensation reaction with in-situ generated imines under room temperature and took non-planar piperazine-based building blocks as reactants to synthesize a flexible polymer POP-PDTR and rigid polymers POP-PDTP and POP-PDTA. Iodine adsorption experiments have verified that their adsorption capacities can reach 3.90 g/g, 3.34 g/g, and 2.59 g/g, respectively. Their excellent chemical structural stability enables them to be reused for at least 5 cycles with stable performance. The results provide a new idea for designing and synthesizing persistent organic pollutant materials with excellent chemical stability and iodine adsorption performance.