锂同位素6 Li和7Li是核聚变所需的重要原料,故锂同位素分离是核能开发必须解决的关键技术.本文系统综述了以冠醚类化合物为化学交换体系分离锂同位素的研究进展,详细讨论了冠醚分子的结构如冠醚环大小、给体原子种类、侧链种类,以及锂盐配位阴离子种类,溶剂种类,化学交换温度等因素对冠醚锂同位素分离效应的影响规律.结果表明,冠醚类化合物具有高的锂同位素分离因子,是非常有前途的锂同位素分离方法,但是以小分子冠醚为萃取剂的液液萃取体系冠醚易于流失,无法重复利用,因此其未来发展方向是制备冠醚固载聚合物,采用固载冠醚的液固体系分离锂同位素,提高分离效率,以实现其工业化应用.
Lithium isotopes 6Li and 7 Li are required in nuclear fusion reactions.The development of lithium isotopes separation is of great importance for nuclear energy development.Although various methods have been developped for lithium isotopes separation,chemical exchange method using crown ethers as lithium isotope receptor has attracted important attention due to its high separation factor and efficiency.This review presents the latest research development and progress of crown ethers as chemical exchange systems for lithium isotopes separation.The mechanism and impact factors,such as size of macrocycle ring,side chain of crown ethe,donor atom type of crown ether ring,kinds of counter anion of lithium salts,solvent,and temperature for lithium isotopes separation are discussed.One of the important development directions is to preparate crown ethers graft polymeric materials and develop relative methods for lithium isotopes separation.