Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
J Hazard Mater. 2018 Apr 5;347:478-485. doi: 10.1016/j.jhazmat.2017.12.068. Epub 2017 Dec 29.
Diglycolamide (DGA)-functionalized tripodal ligands offer the required nine-coordinated complex for effective binding to a trivalent lanthanide/actinide ion. A N-pivot tripodal ligand (TREN-DGA) containing three DGA pendant arms was evaluated for the extraction and supported liquid membrane transport studies using PTFE flat sheets. Solvent extraction studies indicated preferential extraction of 1:1 (M:L) species, while the metal ion extraction increased with increasing HNO concentration conforming to a solvated species extraction. Flat sheet-supported liquid membrane studies, carried out using 4.0 × 10 M TREN-DGA in 95% n-dodecane + 5% iso-decanol indicated faster mass transport for Eu ion as compared to Am ion. The determined transport parameters indicated slow diffusion of the M-TREN-DGA (M = Am or Eu) complex being the rate-determining step. The transport of lanthanides and actinides followed the trend: Eu > Am Pu >> UO and Am can be selectively separated from a mixture of U and Pu by oxidizing the latter to its +6 oxidation state. The liquid membrane stability was not encouraging and was deteriorating the transport efficiency with time, which was attributed to carrier loss into the aqueous phases.
二甘醇酰胺（DGA）功能化的三脚架配体提供了所需的九配位络合物，可有效结合三价镧系/锕系离子。评估了一种含三个 DGA 侧臂的 N-枢轴三脚架配体（TREN-DGA），用于使用 PTFE 平板进行萃取和支撑液膜传输研究。溶剂萃取研究表明优先提取 1:1（M:L）物种，而随着 HNO3浓度的增加，金属离子萃取增加，符合溶剂化物种萃取。使用 4.0×10-3 M TREN-DGA 在 95%正十二烷+5%异癸醇中进行的平板支撑液膜研究表明，Eu 离子的质量传输速度比 Am 离子快。确定的传输参数表明，M-TREN-DGA（M=Am 或 Eu）配合物的扩散缓慢，是速率决定步骤。镧系元素和锕系元素的传输遵循以下趋势：Eu>Am>Pu>>UO，并且可以通过将后者氧化到+6 氧化态来从 U 和 Pu 的混合物中选择性地分离出 Am。液膜稳定性并不理想，并且随着时间的推移会降低传输效率，这归因于载体损失到水相中。
