Extraction Separation Process of Minor Actinide Elements using Biomimetic Polymer Gel

仿生聚合物凝胶提取分离微量锕系元素的工艺

基本信息

批准号：
13480144
负责人：
TAKESHITA Kenji
金额：
$ 0.96万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

The object of this research is to synthesize biomimetic polymer gels that can extract and release minor actinide elements by thermal-swing operation and to test the extractability of a soft metal (Cd(II)) and a minor actinide (Am(III)). The investigation results obtained are summarized as follows ;(1)A thermosensitive NIPA (N-isopropylacrylamide) gel copolymerized with a nitrogen donor ligand, BTP (2,6-di(3-vinylbenzy1-1,2,4-triazol-5-yl)pyridine), was synthesized as a biomimetic gel. A new polymerization method, ultrasound polymerization method, was proposed for the synthesis of homogeneous copolymer of NIPA and BTP(2) The development of gel that can recognize the softness of metal ion is required for the selective extraction trivalent minor actinides Am and Cm. In this study, the extraction of a soft metal, Cd(II), with BTP-NIPA gel were tested and the recognition of softness of metal ion by BTP-NIPA gel was evaluated. Cd(II) was extracted in the gel shrunken at temperature above LCS … More T (Lower Critical Solution Temperature) and released from that swollen below LTST Such thermal-swing extraction was achieved successfully by use of gel polymerized under the irradiation of ultrasound(3) When the content of BTP was increased, BTP branches were formed in the gel Since these BTP branches did not act as crosslinking agent, Cd(II) extracted on the branched BTP molecules was not released by the phase transition from the shrinking state to the swelling one. The formation of branch structure is undesirable for stable thermal-swing extraction operation. The development of new polymerization technique is required for depressing the branch formation and further enhancing the extraction capacity.(4) The extraction tests of Am(III) were carried out by a biomimetic gel copolymerized with NIPA and a phosphorus acid compound (MR). Am(III) was extracted at temperature above LCST (5℃) and released successfully below LCST (40℃) The extraction ability of Am(III) was not changed by the repetition of thermal-swing operation. These results suggest that the thermal-swing extraction using biomimetic gel is useful for the recovery of Am(III). Less

本研究的目的是合成可通过热变操作提取和释放次锕系元素的仿生聚合物凝胶，并测试软金属（Cd（II））和次锕系元素（Am（III））的提取能力。所得研究结果总结如下：(1)与氮供体配体BTP共聚的热敏NIPA(N-异丙基丙烯酰胺)凝胶合成了仿生凝胶(2,6-二(3-乙烯基苯甲基1-1,2,4-三唑-5-基)吡啶)，提出了一种新的聚合方法——超声聚合法来合成均相共聚物。 NIPA 和 BTP (2) 选择性提取三价次锕系元素 Am 和 Cm 需要开发能够识别金属离子柔软度的凝胶。使用 BTP-NIPA 凝胶对软金属 Cd(II) 进行了测试，并评估了 BTP-NIPA 凝胶对金属离子柔软性的识别，并在高于 LCS T（较低温度）的温度下收缩的凝胶中提取 Cd(II)。临界溶液温度）并从低于 LTST 的膨胀中释放。通过使用在超声波照射下凝胶化的聚合物成功地实现了这种热变提取（3）当 BTP 含量增加时，BTP凝胶中形成支链由于这些 BTP 支链不充当交联剂，因此在支化 BTP 分子上萃取的 Cd(II) 不会通过从收缩状态到溶胀状态的相变而释放。支链结构的形成是不希望的。为了实现稳定的变温萃取操作，需要开发新的聚合技术来抑制支链形成并进一步提高萃取能力。(4)采用共聚仿生凝胶进行Am(III)的萃取试验。与 NIPA 和磷酸化合物 (MR) 一起在高于 LCST (5℃) 的温度下萃取 Am(III)，并在低于 LCST (40℃) 的温度下成功释放 Am(III) 的萃取能力不会因重复加热而改变。这些结果表明，使用仿生凝胶的热变压萃取对于 Am(III) Less 的回收是有用的。