New Polymeric Materials for Gaseous Iodine and Methyl Iodide Sequestration

This study presents a new polyimine as an exceptionally effective adsorbent for mitigating the release of volatile radionuclides, including iodine and methyl iodide, produced during the processing of nuclear fuel. The polymer named ADM3 is synthesized via the polycondensation reaction of Tris(4-formylphenyl)amine and 3,3-diaminobenzidine. The synthesis and thermal stability of the polymer are confirmed by NMR, FTIR, XRD, and TGA studies, indicating that the polymer remains thermally stable up to 300°C. The Brunauer–Emmett–Teller (BET) surface area of ADM3 is determined to be 40 m²/g, indicating that the polymer's nature is relatively porous. The X-ray photoelectron spectroscopy (XPS) results showed that the ADM3 polymer and iodine/methyl iodide interacted significantly. The adsorption studies indicate remarkable adsorption capacities of ADM3 for iodine (1842.9 mg/g) and methyl iodide (854.07 mg/g). Importantly, ADM3 exhibits sustained performance across five regeneration cycles, underscoring its potential for long-term, sustainable application in the management of nuclear waste. This research offers critical insights into the adsorption mechanisms of these hazardous species, thereby facilitating the development of advanced polymeric adsorbents to tackle significant challenges in nuclear safety and environmental protection.