自生模板法构筑的富氮微孔聚合物纳米管及其放射性碘俘获性能

More recently, radioactive iodine and its organic iodine have become the major pollutant in nuclear waste and medical industry. Currently, solid adsorbents play an important role in the capture of radioactive iodine. However, in most cases, the known amine-modified porous carbons frequently used for iodine adsorption are featured by the poor stability and the possibility to cause further serious environmental impact in use. Hence, the development of effective and safe iodine capture materials remains a great challenge in the field of material chemistry and environment. The purpose of this project is to design and develop a new nitrogen-rich conjugated microporous polymer with high surface area and pore volume using triazine, cyclotriphosphazene or heptazine as the building block. Based on the in-situ template approach, microporous polymer materials with nanotube morphologies in this work will be synthesized, the structure of which could serve as good channels for the transport and storage of iodine molecules, and therefore exhibit high capture capacity and selectivity for iodine adsorption. The regulatory mechanism of the morphology and the pore structure will be studied. This project will mainly focus on the influence of the morphology and the structure of the materilas on the physicochemical stability and iodine capture performance, and then achieve an appropriate regulation of the iodine capture capacity. This work will provide a new reference for the design and preparation of novel microporous organic polymers as well as a new approach for the capture of radioactive pollutants.

放射性碘129I和131I及其有机碘化物是核工业和医学诊疗中产生的主要污染物。有机胺浸渍的活性炭吸附法是碘废料处理的主流技术之一，但存在稳定性差、易导致二次污染等缺点，寻找安全高效的碘俘获技术是材料、化学和环境科学领域的研究重点和国际前沿。为此，本项目设计将富含路易斯碱的结构单元如均三嗪、环磷腈或庚嗪环等构筑到具有高比表面积和孔容的共轭微孔聚合物上并调控孔径和共轭程度；设想利用自生模板法构建碘吸附的管状通道并调控其中关键因素，探索形成聚碘链的可能机制，开发出对碘及含碘有机物结合力强、吸附量高、可循环且安全高效的俘获材料；研究孔结构调控策略和形貌调控及生长机制，重点研究材料形貌、富氮结构基元等对碘和碘化物吸附性能和固碘机制以及物理化学稳定性等影响规律，实现碘俘获能力的适度调控，为新型有机微孔聚合物的设计及开发提供新思路,为减小放射性污染领域提供新途径。

近年来共轭微孔聚合物由于其高比表面积、轻质的骨架构造、丰富的构建与改性方法，被广泛应用于放射性碘及其有机碘化物吸附。本项目从结构设计的角度出发，设计功能性高比表面积和孔容的共轭微孔聚合物，开发出对碘及含碘有机物结合力强、吸附量高、可循环且安全高效的俘获材料。.1.金属有机聚合物骨架中引入二茂铁结构单元，掺入金属铁活性位点，能有效分散金属铁原子，同时避免传统金属掺杂容易团聚渗出，影响聚合物吸附性能，进一步提高其吸附焓及保持其良好的化学及热稳定性。通过Schiff碱反应得到的含二茂铁砌块的多孔有机聚合物(FcTz-POP)，含有该砌块的多孔聚合物具有良好的稳定性，并显著提高了碘的蒸气容量。.2.将富含路易斯碱的结构单元如均三嗪、环磷腈或庚嗪环等构筑到具有高比表面积和孔容的共轭微孔聚合物上并调控孔径和共轭程度，提高碘的吸附量，为开发具有高吸附量的多孔材料提供了一种可行的方法。.3.碘分子等客体分子进入孔道的路径，取决于主体形貌。针对大多数聚集为球形的微孔有机聚合物对客体分子吸附扩散速率慢的问题。提出将氨基功能化的微孔有机聚合物，通过简单的一步改性富羧基微孔有机聚合物。通过一锅式Friedel-Crafts酰化聚合（方案 4），分别使用吡喃二酸酐（PMDA）和对苯二甲酰氯（TC）作为酰化试剂，很容易制备出两个系列的柔性酮基桥式纳米有机聚合物（NOP）。