High-capacity functional silsesquioxane polymers for capturing I₂ and CO₂ via phosphazene functionalization

Abstract Hybrid porous polymers (PCSs) demonstrate significant efficacy in capturing gaseous radioactive iodine, attributable to their high surface area, structural stability, and tunable porosity. This study presents the development of phosphonitrile-functionalized cage-type polydisilsesquioxane (POSS)-based hybrid porous polymers. Among these, PP-1 shows a BET surface area of 468.84 m²g −1 and pore sizes of 5μm, with an iodine adsorption capacity of 4.08 g/g, exceeding most current materials. This article investigates the stability of composite materials through chemical and adsorption/desorption experiments. After three cycles of adsorption experiments, the capacity remained at 64%. The addition of POSS enhances stability and increases adsorption sites, improving iodine capture. This research provides valuable insights for designing novel iodine adsorbents.