基于新功能单体与纳米结构的稀土离子印迹材料研究

There are several studies have been published with respect to the preparation and applications of ion imprinted polymers (IIP) for rare earth. However, there is almost no reports involved the ion imprinted materials for a lot of the rare earth ions, and almost the same polymerization method as well as the functional monomer have been used in the preparation of rare earth ion imprinted polymers in the studies reported. According to the problems described as above, the surface molecular imprinting technique integrated with the nanotechnology and application of the new compounds, which will be designed and prepared in this project, as functional monomer is considered for the preparation of rare-earth ion imprinted materials with nanostructured. The rare-earth ions which have not been studied in the ion-imprinting technique such as Ce, Pr, Gd, Tb and Sc, et al, are selected in this project as the objects for study. The functional monomer with oxygenous heterocyclic, phosphate group, crown ether and calixarene will be designed and prepared by the computer aided design technique according to the theory of hard and soft acids and bases (HSAB) together with the results obtained from the studies on extractant and chelating agent for rare earth. The ion imprinting technique for the preparation of nanostructured imprinted materials including the method using template as the sacrificial material and core-shell polymerization will be studied, and the conditions for the preparation of ion imprinted materials will be optimized. The structure, properties and mechanization of these materials will be investigated.Based on the above investigations, some solid phase extraction and liquid chromatography methods with high selectivity and recovery will be developed and used for the separation and enrichment of rare earth from minerals and discard materials or as a sample pretreatment technology for the determination of rare earth.

针对稀土离子印迹聚合物现有研究中存在聚合方法与功能单体种类单一，而多数稀土离子的印迹材料还未见研究等问题，本项目拟依据软硬酸碱理论，并借鉴稀土离子萃取剂与螯合剂的研究成果，引入含氧杂环、磷酸基、冠醚或杯芳烃，通过计算机辅助设计技术，设计、合成针对特定稀土离子的功能单体。在此基础上，结合纳米技术与表面印迹技术，引入牺牲模板法和核-壳聚合法，在系统优化材料的制备条件后，制备出对稀土特别是其印迹材料还未见报道的Ce、Pr、Gd、Tb和Sc等具有理想识别性能、结合容量和传质速度的纳米结构印迹材料，表征其结构，研究其识别机理，并用其建立分离、富集稀土离子的固相萃取与液相色谱分离方法，用于矿产、二次资源或环境样品等复杂体系中稀土的分离、富集及样品前处理，为离子印迹技术及稀土的分离富集与稀土二次资源的循环利用提供参考。

本项目针对稀土元素分离难度大和现有分离、检测技术选择性差、操作烦琐等问题，结合离子印迹聚合物对目标物的高选择性识别能力，开展了稀土离子印迹聚合物的研究工作，主要目的是制备能够高选择性、高效或高灵敏度地分离富集或检测稀土离子的新材料。为此，项目首先根据稀土离子的配位特点，引入杂环、氧原子为配位原子，设计、合成了7个新的功能单体，并利用这些功能单体，以纳米TiO2或多壁碳纳米管等纳米材料为载体，采用表面印迹技术，通过正交试验设计法或单因素轮换法优化了材料的制备条件后，分别制备了Ce(III)、Pr(III)、Eu(III)、Tb(III)和La(III)的离子印迹聚合物，同时以这些印迹聚合物作为吸附材料，建立了目标稀土离子（模板离子）的印迹固相萃取方法，这些方法普遍表示出了对目标稀土离子的高萃取率与萃取选择性，它们对目标离子的萃取率一般在80%以上，而对其它共存离子包括其它稀土离子的萃取率一般在30%以下。在上述研究基础上，项目还利用分子印迹聚合物对目标离子的高选择性和吸附能力，将其作为电化学传感器的选择性识别与信号放大元素，制备了三种Ce(III)和4种Eu(III)的离子印迹电化学传感器，建立了3种用于检测Ce(III)和4种用于检测Eu(III)的电化学方法。这些方法灵敏度高（个别传感器的检测限可以达到10-11mol/L）、选择性好，能用于食品、环境以及催化剂等工业产品中Ce(III)或Eu(III)的检测。.项目圆满完成了所有研究内容，取得了预期成果，共发表了研究论文16篇，其中SCI收录论文14篇，申请发明专利1项目，培养毕业博士研究生2人、硕士研究生5人。