Diglycolamic Acid Functionalized CNTs for Preferential Selection of Eu(III) over Am(III) Ion: Density Functional Theoretical Modelling Validated by Experiments

Abstract

We report the structure, bonding, energetic, and thermodynamic parameters of Eu³⁺ and Am³⁺ with diglycolamic acid functionalized CNTs at BP86 and B3LYP functional level of theory using SVP and TZVP basis set. The free energy of extraction, ΔG_ext, of Eu³⁺ and Am³⁺ was computed using standard thermodynamical procedure in conjunction with COSMO (conductor like screening model) model. The value of ΔG_ext for Eu³⁺ ion was found to be higher than that of Am³⁺ as observed in the extraction experiments. The HOMO-LUMO analysis indicates that Eu³⁺ ion is harder than Am³⁺ ion leading to stronger interaction with hard donor based DGA-CNT.

Keywords:

• diglycolamic acid
• functionalized CNT
• Am³⁺-Eu³⁺ separation
• density functional theory

ACKNOWLEDGEMENTS

The authors are very thankful to Dr. A. Goswami and Dr. P. K. Mohapatra, RCD, BARC for allowing the uptake capacity measurement of the adsorbent. The Computer Division, BARC, is acknowledged for providing the Anupam supercomputing facility.