Radiolytic degradation of hydrophilic PyTri ligands for minor actinide recycling

Abstract

The 2,6-bis[1H-1,2,3-triazol-4-yl]-pyridine (PyTri) chelating unit has already shown promising properties for application to advanced hydrometallurgical processes aimed at recovering minor actinides from highly active raffinate. Radiolytic stability is an undeniable key requirement for chemicals involved in highly radioactive solutions partitioning, since radiolysis can have a huge impact on system safety and performances. In this work, the radiolytic degradation of two hydrophilic PyTri complexing agents was investigated by different analytical techniques. The radiation damage was delivered by a 60 Co source. The main radiation-induced ligand degradation by-products were hypothesized. Unprecedented PyTri ligands radiolytic stability was proved, further recommending their implementation in future partitioning processes.

Effects of Gamma Irradiation on the Extraction Properties of Innovative Stripping Solvents for i-SANEX/GANEX Processes

“…It was concluded that the PyTri chelating unit should not present neither hydrolytic nor radiolytic degradation. This is coherent with FT-Raman results, since the intensities of the Raman bands referred to vibrational modes of the aromatic moiety of the ligands remain unchanged 51 .…”

“…NMR spectroscopy was employed with the purpose of confirming the preliminary results already obtained by ESI-MS and FT-Raman, whose results have already been published elsewhere 51 . The NMR spectra are reported in SI.…”

“…In particular, PTD was already successfully tested in an industrial-like single-stage centrifugal contactor device, proving its effectiveness in separating trivalent minor actinides from Ln . Also, hydrolytic and radiolytic stabilities of aqueous stripping solvents based on PTD or PTT have already been outlined but still deserve further investigations . In that previous work, radiation-induced ligand degradation was investigated by FT-Raman spectroscopy and some byproducts were identified by electrospray ionization-mass spectrometry (ESI-MS).…”

“…45 Also, hydrolytic and radiolytic stabilities of aqueous stripping solvents based on PTD or PTT have already been outlined but still deserve further investigations. 46 In that previous work, radiation-induced ligand degradation was investigated by FT-Raman spectroscopy and some byproducts were identified by electrospray ionization-mass spectrometry (ESI-MS). The main aim of this paper is to shed light on the preservation of the stripping performances of irradiated PTD and PTT solutions.…”

Structural properties of the chelating agent 2,6-bis(1-(3-hydroxypropyl)-1,2,3-triazol-4-yl)pyridine: a combined XRD and DFT structural study

“…PTD also features sought-aer characteristics which make it suitable for industrial application: water solubility and complete incinerability. [17][18][19] In addition, PTD has been intensively studied as terdentate chelating agent for different applications such as catalysis or biomedical application 20 both in supramolecular and coordination chemistry. 21 From a fundamental point of view, the full three-dimensional characterization of PTD, despite its important role in complex formation, remains still unpublished.…”