Super Cost-Effective and Scalable Imine-Based Sorbent With Field Attraction and In Situ Fixation for Efficient Capture of Diverse Iodine Species under Industrial Conditions.

Abstract

Gaseous radioiodine under industrial conditions (typically ≥ 150 °C, ≥ 90% humidity) poses great challenges on conventional porous sorbents, where elevated molecular kinetic energy and iodine aerosol formation lead to desorption and pore blockage, resulting in a significant reduction in capture capacities. Here, we propose an electrostatic field attraction and in situ encapsulation synergistic strategy and demonstrate its effectiveness in an imine-based adsorbent, IPIN-P@MF. In this system, the polarized carboxylate groups in ionic polyimine network (IPIN) create a strong electrostatic field for directional iodine attraction, while multiple nitrogen sites and carbonyl-rich additives enable chemical fixation through N-methylation and complexation. This dual mechanism effectively addresses the limitations of conventional pore confinement approaches, allowing IPIN-P@MF to achieve a record-high dynamic I₂ uptake capacity of 160.7 wt.% at 150°C and 90% RH, and maintain filtration efficiency above 99.8% under simulated industrial conditions. The entire IPIN-P@MF can be fabricated via solution processing under mild ambient conditions, offering remarkable cost-effectiveness (0.126 USD per gram of iodine captured) and scalability (dimensions >1.8 meters), thereby providing a practical and scalable pathway for radioactive iodine abatement in nuclear off‑gas treatment and emergency response.