Stability of Different BTBP and BTPhen Extracting or Masking Compounds against γ Radiation.

The radiolytic stability of hydrophobic extracting compounds CyMe4-BTBP and CyMe4-BTPhen and a hydrophilic masking agent (PhSO3H)2-BTPhen, widely employed for trivalent minor actinoid and lanthanoid separation, against γ radiation was tested. Even though the solvent with a promising fluorinated diluent BK-1 provides better extraction properties compared to octan-1-ol, its radiation stability is much lower, and no extraction was observed already after an absorbed dose of 150 kGy (CyMe4-BTBP) or 200 kGy (CyMe4-BTPhen). For the (PhSO3H)2-BTPhen hydrophilic masking agent, the results showed that the rate of radiolytic degradation was significantly higher in 0.25 M HNO3 than in 0.5 M HNO3. For both the hydrophobic and hydrophilic agents, degradation was slower in the presence of both organic and aqueous phases during irradiation.

Extraction of minor actinides, lanthanides and other fission products by silica-immobilized BTBP/BTPhen ligands.

Novel BTBP [bis-(1,2,4-triazin-3-yl)-2,2'-bipyridine]/BTPhen [bis-(1,2,4-triazin-3-yl)-1,10-phenanthroline] functionalized silica gels have been developed to extract minor actinides, lanthanides and other fission products. BTPhen functionalized silica gel is capable of near-quantitative removal of Am(iii) in the presence of Eu(iii) from aqueous HNO3, while BTBP functionalized silica gel is able to remove problematic corrosion and fission products that are found in PUREX raffinates.

Synthesis and Screening of Modified 6,6'-Bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydrobenzo[e][1,2,4]triazin-3-yl)-2,2'-bipyridine Ligands for Actinide and Lanthanide Separation in Nuclear Waste Treatment.

Effects of chloro and bromo substitution at the 4-position of the pyridine ring of 6,6'-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydrobenzo[e][1,2,4]triazin-3-yl)-2,2'-bipyridine (CyMe4-BTBP) have been studied with regard to the extraction of Am(III) from Eu(III) and Cm(III) from 0.1-3 M HNO3. Similarly to CyMe4-BTBP, a highly efficient (DAm > 10 at 3 M HNO3) and selective (SFAm/Eu > 100 at 3 M HNO3) extraction was observed for Cl-CyMe4-BTBP and Br-CyMe4-BTBP in 1-octanol but in the absence of a phase-transfer agent.

Hydrophilic sulfonated bis-1,2,4-triazine ligands are highly effective reagents for separating actinides(iii) from lanthanides(iii) via selective formation of aqueous actinide complexes.

We report the first examples of hydrophilic 6,6'-bis(1,2,4-triazin-3-yl)-2,2'-bipyridine (BTBP) and 2,9-bis(1,2,4-triazin-3-yl)-1,10-phenanthroline (BTPhen) ligands, and their applications as actinide(iii) selective aqueous complexing agents. The combination of a hydrophobic diamide ligand in the organic phase and a hydrophilic tetrasulfonated bis-triazine ligand in the aqueous phase is able to separate Am(iii) from Eu(iii) by selective Am(iii) complex formation across a range of nitric acid concentrations with very high selectivities, and without the use of buffers. In contrast, disulfonated bis-triazine ligands are unable to separate Am(iii) from Eu(iii) in this system. The greater ability of the tetrasulfonated ligands to retain Am(iii) selectively in the aqueous phase than the corresponding disulfonated ligands appears to be due to the higher aqueous solubilities of the complexes of the tetrasulfonated ligands with Am(iii). The selectivities for Am(iii) complexation observed with hydrophilic tetrasulfonated bis-triazine ligands are in many cases far higher than those found with the polyaminocarboxylate ligands previously used as actinide-selective complexing agents, and are comparable to those found with the parent hydrophobic bis-triazine ligands. Thus we demonstrate a feasible alternative method to separate actinides from lanthanides than the widely studied approach of selective actinide extraction with hydrophobic bis-1,2,4-triazine ligands such as CyMe4-BTBP and CyMe4-BTPhen.

Effective separation of Am(III) and Eu(III) from HNO3 solutions using CyMe4-BTPhen-functionalized silica-coated magnetic nanoparticles.

It has been shown that CyMe4-BTPhen-functionalized silica-coated maghemite (γ-Fe2O3) magnetic nanoparticles (MNPs) are capable of quantitative separation of Am(III) from Eu(III) from HNO3 solutions. These MNPs also show a small but significant selectivity for Am(III) over Cm(III) with a separation factor of around 2 in 4 M HNO3. The water molecule in the cavity of the BTPhen may also play an important part in the selectivity.