Highly efficient iodine capture by task-specific polyethylenimine impregnated hypercrosslinked polymers

Abstract

Abatract The primary challenge in environmental remediation is keeping the balance between performance and economy for practical application. The usage of hypercrosslinked polymers as iodine capture adsorbents overcomes the shortcomings of commonly used porous organic polymers adsorbents including the usage of expensive catalysts or monomers and complicated synthesis procedures. This issue is the first attempt to prepare polyethylenimine impregnated hypercrosslinked polymers with a high density of nitrogen atoms designed for iodine capture. The resulting polymers exhibited ultrahigh iodine uptake capacities up to 607 wt% and the capture process fitted the pseudo-second-order model well. Porous characteristics, electron-rich aromatic networks, and abundance nitrogen atoms in polyethylenimine contributed to the high capture capacity. Results indicated that the interactions between iodine and adsorbents were charge transfer and the form of captured iodine was polyiodide. Furthermore, the polymers could be recycled with 93.4% iodine uptake capacity maintained after four cycles. The work presented a new benchmark for using hypercrosslinked polymers as economical materials for iodine capture.