Probing the interaction of U(vi) with phosphonate-functionalized mesoporous silica using solid-state NMR spectroscopy.

The fundamental interaction of U(vi) with diethylphosphatoethyl triethoxysilane functionalized SBA-15 mesoporous silica is studied by macroscopic batch experiments and solid-state NMR spectroscopy. DPTS-functionalized silica has been shown to extract U(vi) from nitric acid solutions at or above pH 3. Extraction is dependent on pH and ionic strength.

Development and Testing of Diglycolamide Functionalized Mesoporous Silica for Sorption of Trivalent Actinides and Lanthanides.

Sequestration of trivalent actinides and lanthanides present in used nuclear fuel and legacy wastes is necessary for appropriate long-term stewardship of these metals, particularly to prevent their release into the environment. Organically modified mesoporous silica is an efficient material for recovery and potential subsequent separation of actinides and lanthanides because of its high surface area, tunable ligand selection, and chemically robust substrate. We have synthesized the first novel hybrid material composed of SBA-15 type mesoporous silica functionalized with diglycolamide ligands (DGA-SBA).

Analysis of trivalent cation complexation to functionalized mesoporous silica using solid-state NMR spectroscopy.

Functionalized mesoporous silica has applications in separations science, catalysis, and sensors. In this work, we studied the fundamental interactions of trivalent cations with functionalized mesoporous silica. We contacted trivalent cations of varying ionic radii with N-[5-(trimethoxysilyl)-2-aza-1-oxopentyl]caprolactam functionalized mesoporous silica with the aim of probing the binding mechanism of the metal to the surface of the solid.

Superheavy element flerovium (element 114) is a volatile metal.

The electron shell structure of superheavy elements, i.e., elements with atomic number Z ≥ 104, is influenced by strong relativistic effects caused by the high Z.

Rapid synthesis of radioactive transition-metal carbonyl complexes at ambient conditions.

Carbonyl complexes of radioactive transition metals can be easily synthesized with high yields by stopping nuclear fission or fusion products in a gas volume containing CO. Here, we focus on Mo, W, and Os complexes. The reaction takes place at pressures of around 1 bar at room temperature, i.

Polymer-assisted deposition of homogeneous metal oxide films to produce nuclear targets.

Targets are essential in experimental nuclear sciences as a source of stationary nuclei for nuclear reactions with ion beams. Typically, targets should be chemically pure, uniform, homogeneous and crack-free over the irradiation area, while also being structurally rigid. The polymer-assisted deposition (PAD) method uses a water-soluble multidentate polymer that chelates metal precursors in solution.

Solvation effects on isomeric preferences of curium(iii) complexes with multidentate phosphonopropionic acid ligands: CmH(2)PPA(2+) and CmHPPA(+) complexes.

We have carried out both time-resolved laser fluorescence spectroscopic and computational studies on the complexes of curium(III) with multidentate Phosphonopropionic (PPA) acid ligands. A number of complexes of Cm(III) with these ligands, such as CmH(2)PPA(2+), CmHPPA(+), Cm[H(2)PPA](2)(+), and Cm[HPPA](2)(-) have been studied. Our computational studies focused on all possible isomers in the gas phase and aqueous solution so that the relative binding strengths of carboxylic versus phosphoric groups can be assessed in these multidentate systems.

Uranyl precipitation by Pseudomonas aeruginosa via controlled polyphosphate metabolism.

The polyphosphate kinase gene from Pseudomonas aeruginosa was overexpressed in its native host, resulting in the accumulation of 100 times the polyphosphate seen with control strains. Degradation of this polyphosphate was induced by carbon starvation conditions, resulting in phosphate release into the medium. The mechanism of polyphosphate degradation is not clearly understood, but it appears to be associated with glycogen degradation.

Laser spectroscopic studies of interactions of UVI with bacterial phosphate species.

We have investigated the interactions of UVI with two bacterial phosphate-containing species: Gram-positive Bacillus sphaericus and Gram-negative Pseudomonas aeruginosa. The Gram-positive B. sphaericus was investigated by using Raman spectroscopy and time-resolved laser-induced fluorescence spectroscopy (TRLFS).