Novel calix4arene functionalized diglycolamides for separation of actinides: Supported liquid membrane studies

摘要

For the partitioning of minor actinides, several extractants such as octyl-(phenyl)-N,N-diisobutyl carbamoyl methyl phosphine oxide (CMPO), N,N'-dimethyl-N,N'-dibutyl tetradecyl malonamide (DMDBTDMA) and N,N'-dimethyl-N,N'-dioctyl-2-(2-hexyloxy-ethyl)-malonamide (DMDOHEMA) have been proposed as the extractants [1]. However, in the last decade, diglycolamide (DGA) extractants have drawn attention as very effective ionophores for the complexation of trivalent f-elements [2]. They act as tridentate binding due to the presence of an additional oxygen atom between the carbonyl groups, and therefore display a very high affinity toward actinides and lanthanides as compared to other malonamides. The extraction of metal ions by DGAs have been explained on the basis of a reverse micelle mechanism, which involves extraction of the metal ion into the core of the reverse micelle containing four units of the DGA [3]. It was of interest, therefore, to synthesize a cluster of ligand, where four DGA units can be mounted on a rigid calix[4]arene platform. Present paper deals with the supported liquid membrane (SLM) transport studies on trivalent actinides from nitric acid medium containing novel calix[4]arene functionalized diglycolamide (C4-DGA) ligands as the carrier. Effect of alkyl chain attached to the DGA arms on the complexation of actinide ions was investigated.