Rationally designed pyridinium cationic polymeric network for effective TcO4-/ReO4- remediation

The development of highly efficient and reliable adsorbent towards radiactive 99TcO4 is of great significance. Here, a covalent polymeric network (Py-CPN) based on pyridinium was rationally designed and synthesized through nucleophilic substitution reaction between 3D building unit tetrakis(4(bromomethyl) phenyl) methane (TBPM) and 1,3,6,8-tetra(pyridin-4-yl) pyrene (TPyPy). Due to the rigidity and shape-persistence of tetrahedral unit of TBPM, which benefited rapid ion transportation across the polymeric network, Py-CPN provided high adsorption capacity and fast kinetics towards ReO4 removal. Owing to the introduction of highly hydrophobic and largely conjugated monomer TPyPy, excellent selectivity towards various coexisting anions was achieved. Moreover, the sorption ability of Py-CPN remained stable over a wide range of pH values, including 3 M HNO3 solution and simulated Hanford LAW off-gas recycle wastes. Py-CPN also exhibited excellent recyclability for at least four cycles. Overall, this work provided a new strategy for constructing high-performance polymeric materials for sustainable development of environment protection.(c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

In this work, a covalent polymeric network (Py-CPN) based on pyridinium was successfully designed and synthesized, which showed high efficiency and reliability in adsorbing radioactive 99TcO4. This research has significant implications for environmental protection.