J. Appl. Cryst.の発刊に際して

Chemistry of Diglycolamides: Promising Extractants for Actinide Partitioning

Nouveau Traité de Chimie Minérale.

Complexation and Extraction of Trivalent Actinides and Lanthanides by Triazinylpyridine N-Donor Ligands

Lanthanides(III) and actinides(III) belong to hard elements, preferably bound in complexation reactions to the hard oxygen donor atoms. Correspondingly, studies of complexation of these elements in solutions were until the 1980s performed with complexants bonding the complexed metal ion either exclusively to oxygen atoms or to both oxygen and nitrogen atoms. Such complexes may be very stable in solution, but high stability is not the only property desired. Complexation is a very useful tool for separation of metal ions, if utilized in systems involving two immiscible phases. In such cases, the selectivity of the complexation is a characteristic as valuable or still more valuable.

Complexation and separation of lanthanides(III) and actinides(III) by heterocyclic N-donors in solutions.

6,6′-bis-(5,6-diethyl-[1,2,4]triazin-3-yl)-2,2′-bipyridyl the first example of a new class of quadridentate heterocyclic extraction reagents for the separation of americium(III) and europium(III)

Using small angle X-ray scattering, conductivity, and phase behavior determination, we show that concentrated solutions of molanamide extractants, dimethyldibutyltetradecylmalonamide (DMDBTDMA), are organized in reverse oligomeric aggregates which have many features in common with reverse micelles. The aggregation numbers of these reverse globular aggregates as well as their interaction potential are determined from absolute scattering curves. An attractive interaction is responsible for the demixing of the oil phase when in equilibrium with excess oil. Prediction of conductivity as well as the formation conditions for the third phase is possible using standard liquid theory applied to the extractant aggregates. The interactions, modeled with the sticky sphere model proposed by Baxter, are shown to be due to steric interactions resulting from the hydrophobic tails of the extractant molecule and van der Waals forces between the highly polarizable water core of the reverse micelles. The attractive interacti...

Attractive interactions between reverse aggregates and phase separation in concentrated malonamide extractant solutions

Separation of long-lived radionuclides from high active nuclear waste

Among the different problems to be solved when designing a liquid-liquid solvent extraction process, third phase formation. i.e. the splitting of the organic phase into two layers when extracting high concentration of solutes, like nitric acid or metallic nitrates (here trivalent f ions), is one of the most important to address. In some conditions the formation of a “third phase” is observed with dimethyldibutyltetradecylmalonamide (DMDBTDMA), a potential extractant used in the DIAMEX process We have investigated the phase behavior of the system DMDBTDMA / n-dodecane / water / HNO3, in the acceptable concentration limits for the DIAMEX process.

EFFECT OF NITRIC ACID EXTRACTION ON PHASE BEHAVIOR, MICROSTRUCTURE AND INTERACTIONS BETWEEN PRIMARY AGGREGATES IN THE SYSTEM DIMETHYLDIBUTYLTETRADECYLMALONAMIDE (DMDBTDMA) / n-DODECANE / WATER: A PHASE ANALYSIS AND SMALL ANGLE X-RAY SCATTERING (SAXS) CHARACTERISATION STUDY

The tetradentate ligand (C5‐BTBP) was able to extract americium(III) selectively from nitric acid. In octanol/kerosene the distribution ratios suggest that stripping will be possible. C5‐BTBP has unusual properties and potentially offers a means of separating metals, which otherwise are difficult to separate. For example C5‐BTBP has the potential to separate palladium(II) from a mixture containing rhodium(III) and ruthenium(II) nitrosyl. In addition, C5‐BTBP has the potential to remove traces of cadmium from effluent or from solutions of other metals contaminated with cadmium. C5‐BTBP has potential as a reagent for the separation of americium(III) from solutions contaminated with iron(III) and nickel(II), hence offering a means of concentrating americium(III) for analytical purposes from nitric acid solutions containing high concentrations of iron(III) or nickel(II).

An Investigation into the Extraction of Americium(III), Lanthanides and D‐Block Metals by 6,6′‐Bis‐(5,6‐dipentyl‐[1,2,4]triazin‐3‐yl)‐[2,2′]bipyridinyl (C5‐BTBP)

Charles Madic

Papers

6,6′-bis-(5,6-diethyl-[1,2,4]triazin-3-yl)-2,2′-bipyridyl the first example of a new class of quadridentate heterocyclic extraction reagents for the separation of americium(III) and europium(III)

Attractive interactions between reverse aggregates and phase separation in concentrated malonamide extractant solutions

Separation of long-lived radionuclides from high active nuclear waste

EFFECT OF NITRIC ACID EXTRACTION ON PHASE BEHAVIOR, MICROSTRUCTURE AND INTERACTIONS BETWEEN PRIMARY AGGREGATES IN THE SYSTEM DIMETHYLDIBUTYLTETRADECYLMALONAMIDE (DMDBTDMA) / n-DODECANE / WATER: A PHASE ANALYSIS AND SMALL ANGLE X-RAY SCATTERING (SAXS) CHARACTERISATION STUDY

An Investigation into the Extraction of Americium(III), Lanthanides and D‐Block Metals by 6,6′‐Bis‐(5,6‐dipentyl‐[1,2,4]triazin‐3‐yl)‐[2,2′]bipyridinyl (C5‐BTBP)