Constructing “breathing” dynamic skeletons with extra π-conjugated adsorption sites for iodine capture

Abstract

A series of soft porous aromatic frameworks (PAFs) with additional π-conjugated fragments provides sufficient space for the binding sites which serve as physicochemical stable mediums for radioiodine.

An Azo-Group-Functionalized Porous Aromatic Framework for Achieving Highly Efficient Capture of Iodine

“…13 C solid-state NMR (CP/MAS) spectroscopy was applied to investigate the local structure of LNU-58 ( Figure 2 b). The distinct signals in the range from 110 to 155 ppm were attributed to the aromatic carbon atoms; thereinto, the peak at around 152 ppm was assigned to the carbon atoms attached to the azo groups [ 27 , 28 , 29 ]. The FT-IR and NMR results both proved the successful synthesis of the LNU-58 network.…”

Highly efficient, reversible iodine capture and exceptional uptake of amines in viologen-based porous organic polymers

“…As reported before, ionic pairs on the pore wall generate high polarity, but low-porosity is always observed in charged porous organic polymers when using N 2 as the probe molecule because the strong polarity barely allows N 2 to enter into the pores. 46 In addition, the high interface energy may cause the pores of the viologen-based porous organic polymers to collapse during solvent removal by high-vacuum thermodrying. 48 All the above results demonstrate that by facile nucleophilic substitution, two viologen-based porous organic polymers, POP-V-VI and POP-V-BPY, were successfully synthesized.…”

“…As we know, incorporating open frameworks with intrinsic positive charges, aromatic rings with conjugated p-electrons and heteroatoms (e.g., N, S, P, B) may result in a high affinity for guest molecules possessing a large quadrupole moment (e.g., iodine). 22,34,39,46 Moreover, the strong charge polarization effect generated from positive charges incorporated in the frameworks was regarded as a critical mechanism for selective adsorption towards polar molecules. 47,48 Keeping this in mind, we aim to achieve the coexistence of multiple high affinity sites such as positive charges, aromatic rings and a strong polar skeleton to facilitate development of a high capture capability towards both iodine and amines.…”

Synthesis of thiophene‐based conjugated microporous polymers for high iodine and carbon dioxide capture

“…In view of the above characteristics, this material is very likely to be well applied to the enrichment and recovery of radioactive iodine in nuclear waste under complex environment, which is of great significance to the exploration in this field. In addition, the reported results show the iodine capture capacity of porous adsorbent materials can effectively improve by introducing the active sites with affinity for iodine (such as ionic bonds, benzene rings, triple bonds, π‐electron‐rich, nitrogen‐rich or sulfur‐rich heteroatom groups) into the network structure of CMPs 19–22 . Therefore, choosing building units with iodine affinity to construct CMPs can greatly improve the iodine absorption capacity of adsorbents.…”

“…In addition, the reported results show the iodine capture capacity of porous adsorbent materials can effectively improve by introducing the active sites with affinity for iodine (such as ionic bonds, benzene rings, triple bonds, π-electron-rich, nitrogen-rich or sulfur-rich heteroatom groups) into the network structure of CMPs. [19][20][21][22] Therefore, choosing building units with iodine affinity to construct CMPs can greatly improve the iodine absorption capacity of adsorbents.…”