Rational design of a cationic polymer network towards record high uptake of 99TcO4- in nuclear waste
Rational design of a cationic polymer network towards record high uptake of 99TcO4- in nuclear waste
复制标题
合理设计阳离子聚合物网络以实现核废料中 ~(99)TcO_4~- 的创纪录高吸收
DOI：
10.1007/s11426-020-9962-9
复制
发表时间：
2021-05-20
影响因子：
9.6
通讯作者：
Wang, Shuao
中科院分区：
文献类型：
--
作者：
Li, Jie;Chen, Long;Wang, Shuao
99 Tc是一种长寿命的放射性核素，以TcO 4 -阴离子的形式大量存在于使用过的核燃料中。由于其对锕系元素分离的干扰能力及其在核废物玻璃化过程中的挥发性，因此非常希望将其从废物流中去除。尽管在过去的几年中取得了进展，具有优化的Tc吸收性能和改善的极端条件下的稳定性的阴离子交换材料的设计，仍然是有利于减少废物分配过程中产生的二次放射性固体废物的体积的研究目标。然而，它们的设计理念仍然难以捉摸，挑战来自电荷排斥，空间位阻和材料内反应位点不足。在此，我们提出了一个设计理念的阳离子聚合物网络材料的TcO 4 -分离系统的前体筛选和结构预测。这提供了优化的材料SCU-CPN-2（SCU=Soochow University），其具有极高的正电荷密度，同时保持高耐辐射性。与迄今为止报道的所有阴离子交换材料相比，SCU-CPN-2表现出创纪录的高吸附能力（对替代物ReO 4 -为1，467 mg/g）。SCU-CPN-2除了具有超快的吸附动力学外，对硝酸盐和硫酸盐具有显著的选择性，并且易于回收。
99 Tc is a long-lived radionuclide present in large amounts as TcO 4 - anion in used nuclear fuel. Its removal from the waste stream is highly desirable because of its interference capability with actinide separation and its volatile nature during the nuclear waste vitrification process. Despite the progress achieved in the past few years, the design of anion-exchange materials with optimized Tc uptake property and improved stability under the extreme condition, is still a research goal beneficial for reducing the volume of secondary radioactive solid waste generated during the waste partitioning process. However, their design philosophy remains elusive, with challenges coming from charge repulsion, steric hindrance, and insufficient reactive sites within the materials. Herein, we present a design philosophy of cationic polymer network materials for TcO 4 - separation by systematic precursor screening and structure prediction. This affords an optimized material, SCU-CPN-2 (SCU=Soochow University), with extremely high positive charge density while maintaining high radiation resistance. SCU-CPN-2 exhibits a record high adsorption capacity (1,467 mg/g towards the surrogate ReO 4 - ) compared to all anion-exchange materials reported up to date. In addition to ultrafast adsorption kinetics, SCU-CPN-2 has remarkable selectivity over nitrate and sulfate, and facile recyclability.