Spatial Engineering Direct Cooperativity between Binding Sites for Uranium Sequestration.

Qi Sun,Briana Aguila,Vyacheslav S Bryantsev,Aleksandr S Ivanov,Shengqian Ma,Yanpei Song

doi:10.1002/advs.202001573

Abstract

Preorganization is a basic design principle used by nature that allows for synergistic pathways to be expressed. Herein, a full account of the conceptual and experimental development from randomly distributed functionalities to a convergent arrangement that facilitates cooperative binding is given, thus conferring exceptional affinity toward the analyte of interest. The resulting material with chelating groups populated adjacently in a spatially locked manner displays up to two orders of magnitude improvement compared to a random and isolated manner using uranium sequestration as a model application. This adsorbent shows exceptional extraction efficiencies, capable of reducing the uranium concentration from 5 ppm to less than 1 ppb within 10 min, even though the system is permeated with high concentrations of competing ions. The efficiency is further supported by its ability to extract uranium from seawater with an uptake capability of 5.01 mg g−1, placing it among the highest‐capacity seawater uranium extraction materials described to date. The concept presented here uncovers a new paradigm in the design of efficient sorbent materials by manipulating the spatial distribution to amplify the cooperation of functions.

Highlights

Preorganization is a basic design principle used by nature that allows for promising near-term scalable replacement
The polymer constructed by biphenyldiamine (POP2-NH2) and the corresponding materials from subsequent post-synthetic grafting are chosen as representative samples for thorough descriptions
The results showed that the weight percentage of P species in POP2-PO(OEt)2 was 10.1 wt%, corresponding to around 97% of the amine groups involved in the condensation reaction and confirming high throughput of this transformation

Summary

Discoveries of the proper spatial arrangement of binding sites

We chose phosphorylurea as a chelating group due to its high affinity toward uranium.[8] Regarding the scaffolds, porous organic polymers (POPs) were utilized for regulating the location of the phosphorylurea ligands relative to each other to understand how synergistic pairings can amplify the binding affinity This choice is due to the level of synthetic control of POPs, which allows one to manipulate the compositions and local environments with high fidelity.[9] Sorption tests revealed that the adsorbent with the chelating groups in a convergent orientation, magnifying synergistic effects, displayed an extraordinary affinity and selectivity for uranyl, far outperforming those in a random distribution. The densely populated chelating groups on the porous framework allow ready access to binding sites and, enable high uptake capacities and fast kinetics in uranium extraction

Result and Discussion

Findings

Conclusion

Conflict of Interest