The extraction of uranyl from acidic (HNO3) aqueous solutions toward an ionic liquid phase, C1–C4–imTf2N (1-methyl,3-butylimidazolium Tf2N), has been investigated as a function of initial acid concentration and ligand concentration for two different extracting moieties: a classical malonamide, N,N′-dimethyl-N,N′-dibutylmalonamide (DMDBMA) and a functionalized IL composed of the Tf2N− anion and an imidazolium cation on which a malonamide pattern has been grafted (FIL-MA). The extraction mechanism, as demonstrated through the influence of added C1–C4–imCl or added LiTf2N in the aqueous phase, is slightly different between the DMDBMA and FIL-MA extracting agents. Modeling of the extraction data evidences a double extraction mechanism, with cation exchange of UO22+versus 2 H+ for DMDBMA or versus C1–C4 -im+ and H+ for FIL-MA at low acidic values, and through anion exchange of [UO2(NO3)3]−versus Tf2N− for both ligands at high HNO3 concentrations. The FIL-MA molecule is more efficient than its classical DMDBMA parent.
针对两种不同的萃取分子,研究了
离子液体 C1-C4-imTf2N(
1-甲基,3-丁基
咪唑鎓 Tf2N)从酸性(
HNO3)
水溶液中萃取
铀酰与初始酸浓度和
配体浓度的函数关系:一种是传统的丙二
酰胺,即 N,N′-二
甲基-N,N′-二丁基丙二
酰胺(
DMD
BMA),另一种是由 Tf2N- 阴离子和
咪唑阳离子组成的功能化 IL,其上接枝了丙二
酰胺图案(FIL-
MA)。通过
水相中添加的 C1-C4-imCl 或添加的 LiTf2N 的影响,可以看出
DMD
BMA 和 FIL-
MA 萃取剂的萃取机理略有不同。萃取数据模型证明了双重萃取机制:在低酸值条件下,
DMD
BMA 的阳离子交换为 UO22+ 对 2 H+,FIL-
MA 的阳离子交换为 C1-C4-im+ 和 H+;在高浓度 条件下,两种
配体的阴离子交换为 [UO2(
NO3)3]- 对 Tf2N-。FIL-
MA 分子比传统的
DMD
BMA 母体更有效。