基于铀识别的多孔配位聚合物及其复合膜的制备和吸附机理研究

新兴的多孔配位聚合物（MOF）蕴藏着巨大的潜在应用价值。利用MOF结构可调控、表面易修饰的特点，可制备新型铀吸附功能材料。其铀的特异性识别将是该领域应用的核心支撑技术。我们提出协同识别新概念，即对于水合铀离子，MOF的空腔尺寸、配体功能基团和主客体间氢键等各识别位点的协同贡献，实现识别的高选择性。拟合成具有不同取代基的配体,以之与金属簇自组装构筑MOF。调控孔径大小，并在孔道表面引入能与铀离子形成配位作用的开放官能团，作为铀离子的特异识别位点，以提高铀吸附选择性。系统探索不同的孔道尺寸/取代基对铀离子识别能力，研究其识别机理。在此基础上，进一步将之与金属网或者高分子树脂结合起来,制备高效铀吸附的新型MOF复合膜材料，考察其铀吸附性能并研究其作用机制。本研究将为多孔体系主客体间的表面效应对铀离子的特异识别，得出可行性的科学论据。丰富多孔配位聚合物新的研究领域，开辟铀识别分离的新思路和新方法。

As a new generation of porous materials, the coordination polymers (MOFs) have enormous potential applications. The structures of MOFs can be regulated and its surface can be easily modified. So we can prepare a new-style functional uranium adsorption materials by taking advantage of the characterizations of MOFs. The MOFs' excellent recognition of uranium ions is the key supporting technique in this field. We propose a new concept, namely, synergistic recognition, the cooperation of the size of cavity, the open active groups of functional ligands and the host-guest hydrogen bond as the recognition sites, will achieve a high selectivity of the hydrated uranium ions. Based on the above synergistic recognition concept, this study intends to synthesize a series of functional organic ligands with different substitutes and then to construct various MOFs through self-assembly of metal ions and these organic ligands. The size regulation of pores and the open functional coordination groups being introduced on the surface of pores also serve as excellent recognition sites and cooperate together to improve the adsorption selectivity and the amount of adsorption of uranium ions. The project will explore the different recognition capacities of different pore-size or substituents in order to screen out the appropriate structures, and investigate the recognition mechanism. Further, the efficient composite membrane will be prepared to combine the MOF candidates with some metal meshes or polymer resins. Moreover, its performance of uranium ions adsorption and its mechanism of action also will be investigated. This project will put forward an scientific argument based on the surface synergistic recognition effects between the guest uranium ions and host porous frameworks, which will enrich the new research areas of the porous coordination polymers and open a new approach of uranium separation.