高选择性分离锂同位素新型冠醚类复合吸附材料的制备及构效研究

项目名称： 高选择性分离锂同位素新型冠醚类复合吸附材料的制备及构效研究

项目编号： No.U1430234

项目类型： 联合基金项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 陈靖

作者单位： 清华大学

项目金额： 400万元

中文摘要： Li-6和Li-7是锂的两种稳定同位素，Li-6可用于生产核聚变反应所需的氚，Li-7被广泛用于核反应堆冷却剂和载热剂。研究锂同位素的分离对于发展我国先进核能技术具有重要意义。在众多分离方法中，基于冠醚类化合物对锂的特定络合作用构建的萃取色谱分离方法具有良好的应用前景，然而现有冠醚修饰的吸附材料大多存在吸附容量偏低、动力学速度较慢等缺陷，尚无法满足锂同位素分离的应用需求。本项目拟结合理论计算和分子设计，筛选并合成出一批可有效分离锂同位素的冠醚单体；以化学键合方式分别负载于聚合物微球和有序介孔硅基材料表面，制备出两大类官能化程度高、比表面积大的冠醚复合吸附材料；研究锂同位素的吸附分离行为及其构效关系，确定吸附分离过程的控制因素并阐明吸附机理，基于优化后的材料建立一个可高效分离锂同位素的萃取色谱方法。本项目的完成将为高效分离锂同位素技术的发展提供重要的学科依据。

中文关键词： 锂同位素；分离；冠醚；复合材料；吸附

英文摘要： Lithium-6 and lithium-7 are two stable lithium isotopes. Lithium-6 is valuable as the source material for the production of tritium which is essential for nuclear fusion reactions, while lithium-7 is widely used as nuclear reactor coolant and heating medium. Researches on the separation techniques are of great importance for the development of advanced nuclear energy technology in our country. Among the miscellaneous methods, extraction chromatography based on the crown ethers’ specific coordination with lithium is promising for practical use. However, so far, the reported crown ether decorated adsorption materials still suffered from relatively low adsorption capacity and slow kinetics, which cannot fulfill the requirement of lithium isotope separation. This study intends to develop new crown ether functionalized composites for the efficient separation of lithium isotopes. A series of crown ether molecules will be sorted and synthesized based on theoretical calculation and molecular design, followed by the anchoring to polymeric micro-spheres and ordered mesoporous silicas, respectively. Two categories of crown ether functionalized composites with high functionalization degree and large specific surface area will be obtained. The adsorption behavior towards lithium isotopes as well as the relationship between the structure and performance will be investigated. The controlling factors of the adsorption process and separation mechanism will be elucidated. Finally, by the use of the optimized composites, a chromatographic process will be proposed for the highly efficient separation of the lithium isotopes. This study is expected to provide important scientific supports for the development of lithium isotopes separation technology.

英文关键词： lithium isotope;separation;crown ether;composite material;adsorption