多功能磁性介孔复合微球的设计及对铀的吸附分离研究

The adsorption and separation of uranium in aqueous solution is of great significance for uranium pollution treatment and the recovery of uranium resources. The traditional adsorbents are mainly obtained by modifying mesoporous or microporous materials with active functional groups to achieve the separation and adsorption of uranium. However, the reported materials possess low adsorption capacity, unstable structure, blocked pores, difficulty to be separated, and difficulty to realize long-term circulation. Herein, in this project, it is proposed to exploit a novel, simple and mild method to design synthesize yolk-shell magnetic mesoporous microspheres through the materials engineering combined with mesoporousc structure, magnetic separation, cavity design and organic-inorganic co-assembly strategy. The design synthesis idea is inspired by cell plasmolysis. The key process is to control the reversible swelling and shrinking process of polymerization resin middle layer. It is believed the obtained microspheres possess high specific surface area, large storage cavity, stable and uniform mesostructure, stable and effective magnetic composite, which are favor for adsorption and separation of uranium. The synthesis idea will promote the preparation of multi-functional integrated composite microspheres, promote radionuclide pollution control and recycling.

水溶液中铀的吸附与分离对于铀污染治理以及铀资源回收具有重大意义。传统的吸附剂多采用介孔或微孔载体经过活性官能团修饰来实现铀的分离吸附，存在着吸附容量低，结构不稳定，孔道堵塞，不易分离，难以长期循环使用等问题。本课题通过对纳米材料结构设计，结合介观结构，磁性分离，空腔设计以及有机无机复合的策略，拟探究聚合树脂的可逆溶胀-收缩过程规律，开发一种新颖、简单温和的方法合成具有高比表面积，大储存空腔，稳定的结构，充足的活性官能团，稳定且有效的磁组分的磁性介孔复合微球材料用于吸附分离水中的铀。相关合成思路将推动多功能集成化复合微球的制备研究，促进放射性核素污染治理以及回收利用。

功能介孔材料具有高比表面积，大孔体积以及可调的组分结构等优点，在吸附分离，海水提铀领域具有广阔的应用前景。而传统的蛋黄-蛋壳结构介孔材料的构建历经多步层层组装和夹层牺牲策略，步骤复杂，空腔尺寸难以调控，功能客体物难以定向负载。本项目围绕核壳介孔材料的组装合成，提出了 “类质壁分离”的界面组装思路，通过构建具有低交联度的高分子夹层，利用夹层在特定有机溶剂中的可逆溶胀-收缩作用，制备高质量的Yolk-Shell结构磁性介孔微球，并同步实现高活性贵金属纳米颗粒的限域负载。在此基础上，进一步拓展实现对介孔孔参数、形貌结构、以及骨架组分的灵活调控。分析评价不同组分的介孔材料对水体中放射性元素铀的吸附分离性能，分析吸附机制，获得对水体中铀具有高吸附容量，高选择性的介孔功能材料。通过700L的天然海水试验，吸附量达10mg/g吸附剂。为海水提铀大规模应用奠定基础。