Liquid–Liquid Extraction of the Eu(III) Cation by BTP Ligands into Ionic Liquids: Interfacial Features and Extraction Mechanisms Investigated by MD Simulations

Rachel SCHURHAMMER¹, Thomas MANGIN¹, Georges WIPFF^1
1Université de Strasbourg - Modélisation et Simulations Moléculaires UMR 7140, Strasbourg, France

In the context of nuclear fuel retreatment process, the separation of actinides (An3+) from lanthanides (Ln3+) remains a key problem. Soft (S, N) donor ligands, such as bis-triazinyl pyridine (R-BTP), have been designed to selectively complex An3+ ions during the extraction processes.
Bhattacharyya et al. proposed to use Ionic Liquids (ILs) as extractant phase as an alternative to more classical organic solvents to enhance extraction and improve the radiation resistance of R-BTP1 during lanthanides extraction processe.
We use Molecular Dynamic (MD) simulations and Potential of Mean Force (PMF) calculations on Eu(NO3)3 salt with Me-BTP at a [BMI][Tf2N]/water and [OMI][Tf2N]/water interface to get insights from the Eu3+ extraction systems. We report here the results were we particularly focused on the (i) Ligand and complex partitioning (ii) Free energy profile while crossing interface (iii) Role and nature of the IL phase during the phase separation and the extraction process.