权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Separation of lanthanide elements by ion recognition of polymer gel copolymerized with acidic phosphorus compound

酸性磷化合物共聚聚合物凝胶离子识别分离镧系元素

基本信息

批准号：
09650840
负责人：
TAKESHITA Kenji
金额：
$ 1.73万
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 (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650840/
关键词：
extraction lanthanide elment mutual separation gel thermosensitive gel phase transition phosphoric acid ester thermal swing リン酸ジエステルアルキル基立体障害イオン認識

项目摘要

The extraction of lanthanide ion between an aqueous solution and a thermosensitive polymer gel, n-isopropylacrylamide (NIPA) gels copolymerized with 2-metacrloxyethylacidphospate (MR) was examined. This polymer gel shows a phase transition phenomena, that is, the structure of gel changes from swelling to shrinking with increasing temperature. The extraction equilibrium of lanthanide ions, La(III) and Sm(III), in an aqueous solution was measured batchwise. The distribution ratio, Kd, increased with increasing temperature. These metal ions can be extracted in the gel at the shrinking condition and cluted by the conformation change of polymer network from shrinking to swelling of gel with decreasing temperature.The extraction mechanism of lanthanide ion, which was estimated from the pH-dependency on Kd, was described simply asLn^<3+> + 3 RH <double arrow> LnR_3 + 3 H^+at both the shrinking and swelling conditions. The number of effective phosphorus molecules for the extraction of lanthanide ion, which was derived from the extraction constants at the shrinking and swelling conditions corresponded to about 80% of copolymerized phosphorus molecules at the shrinking condition and was reduced to about 30% at the swelling condition.The thermal swing tests were carried out to examine the possibility of practical use. It is important practically to maintain the extraction capability of gel in a long-term use. The temperature-dependency of Kd was maintained for repcating the extraction and elution by the thermal swing operation. These results suggest that the phase transition phenomena of thermosensitive gel is applicable to the extraction and elution operations of metal ion.

研究了稀土离子在温敏性高分子凝胶--N-异丙基丙烯酰胺（NIPA）与2-甲基丙烯酰氧乙基磷酸酯（MR）共聚凝胶--之间的萃取行为。这种聚合物凝胶表现出一种相变现象，即随着温度的升高，凝胶的结构由溶胀变为收缩。在水溶液中的镧系元素离子，La（III）和Sm（III）的萃取平衡进行了测定分批。分配比Kd随温度的升高而增大。在收缩条件下，这些金属离子都能被萃取到凝胶中，随着温度的降低，这些金属离子通过凝胶中聚合物网络的构象变化而被萃取，根据pH值对Kd的依赖性，可将其萃取机理简单地描述为Ln ^<3+> +3RH <double arrow>LnR_3 + 3 H^+。由收缩和膨胀条件下的萃取常数推导出萃取镧系离子的有效磷分子数，在收缩条件下相当于共聚磷分子的80%左右，在膨胀条件下减少到30%左右，并进行了热摆动测试以考察实际使用的可能性。在长期使用中保持凝胶的提取能力在实践中是重要的。通过变温操作重复提取和洗脱，保持Kd的温度依赖性。这些结果表明，温敏凝胶的相变现象适用于金属离子的萃取和洗脱操作。