A5029602028- Radioactive element chemistry and processing
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Nuclear Materials and Properties
- Ionic liquids properties and applications
- Extraction and Separation Processes
- Lanthanide and Transition Metal Complexes
- Radioactive contamination and transfer
- Carbon Dioxide Capture Technologies
- Molten salt chemistry and electrochemical processes
- Radiopharmaceutical Chemistry and Applications
- Catalysis and Oxidation Reactions
- Electrochemical Analysis and Applications
- Nuclear materials and radiation effects
- Hydrogen embrittlement and corrosion behaviors in metals
- Non-Destructive Testing Techniques
- Chemical Synthesis and Characterization
- Crystallography and molecular interactions
- Chromatography in Natural Products
- Radiation Therapy and Dosimetry
- Ultrasonics and Acoustic Wave Propagation
- Analytical chemistry methods development
- Metal Extraction and Bioleaching
- Organometallic Complex Synthesis and Catalysis
- Medical Imaging Techniques and Applications
Los Alamos National Laboratory
2013-2024
Government of the United States of America
2023-2024
Los Alamos Medical Center
2014
Division of Chemistry
2009
Pacific Northwest National Laboratory
2008
The University of Texas at Austin
2003-2005
This study examines the rate of oxidative degradation MEA under conditions typical a CO2 capture process. Experiments examined effects amine concentration, loading, O2 and agitation at 55 °C. Degradation rates were quantified by measuring NH3 evolution from solutions using FT-IR analysis. Results show that are controlled physical absorption ranged 0.2 to 8.0 mM/h. Previous studies re-examined compared current appear have been performed mass transfer limited. would indicate previous...
This study examines the effect of a number additives on oxidative degradation monoethanolamine (MEA) in presence dissolved Cu. Additives were selected from three categories: O2 scavengers and reaction inhibitors, chelating agents, stable salts. Three proprietary inhibitors have been identified that significantly inhibit rate at concentrations below 100 mM. Inhibitor A is compound, while Scavengers B C are stoichiometrically degraded to products must be removed an industrial application....
Room-temperature ionic liquids (RTILs) are regarded as green solvents due to their low volatility, flammability, and thermal stability. RTILs exhibit wide electrochemical windows, making them prime candidates media for electrochemically driven reactions such electro-catalysis electro-plating separations applications. Therefore, understanding the factors determining edges of window, stability RTILs, degradation products is crucial improve efficiency applicability these systems. We present...
In alkaline carbonate solutions, hydrogen peroxide can selectively replace one of the ligands in UO2(CO3)34- to form ternary mixed U(VI) peroxo-carbonato species UO2(O2)(CO3)24−. Orange rectangular plates K4[UO2(CO3)2(O2)]·H2O were isolated and characterized by single crystal X-ray diffraction studies. Crystallographic data: monoclinic, space group P21/n, a = 6.9670(14) Å, b 9.2158(10) c 18.052(4) Z 4. Spectrophotometric titrations with H2O2 performed 0.5 M K2CO3, UO2(O2)(CO3)24−...
In alkaline carbonate solutions both technetium and uranium exist as anionic species, TcO4– UO2(CO3)34–, which makes separating Tc U from each other more challenging compared to acidic PUREX type where forms neutral or cationic complexes. We tested the batch separation of 99Tc, 238U, 239Pu using anion exchange resins with different properties, including Purolite A530E, Reillex HPQ, Dowex Marathon WBA. Overall, highest Kd values for pertechnetate were achieved strong base in lowest...
Intra- and intermolecular force field parameters for the interaction of actinyl ions (AnO2(n+), where, An = U, Np, Pu, Am n 1, 2) with water have been developed using quantum mechanical calculations. Water was modeled extended simple point charge potential (SPC/E). The resulting consists a form in which interactions are pairwise Lennard-Jones functions plus partial terms. Intramolecular bond stretching angle bending treated harmonic functions. new potentials were used to carry out extensive...
Both binary and ternary solid complexes of Pu(III) Pu(IV) oxalates have been previously reported in the literature. However, uncertainties regarding coordination chemistry extent hydration some compounds remain mainly because absence any crystallographic characterization. Single crystals hydrated Pu(III), Pu2(C2O4)3(H2O)6·3H2O (I) Pu(IV), KPu(C2O4)2(OH)·2.5H2O (II), were synthesized under moderate hydrothermal conditions characterized by single crystal X-ray diffraction studies. Compounds I...
A fundamental understanding of the behavior actinides in ionic liquids is required to develop advanced separation technologies. Spectroscopic measurements indicate a change coordination uranyl hydrophobic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][Tf2N]) as water added system. Molecular dynamics simulations dilute (UO2(2+)) and plutonyl (PuO2(2+)) ) solutions [EMIM][Tf2N]/water mixtures have been performed order examine molecular-level actinyl cation...
Task-specific ionic liquids (TSILs) present an opportunity to replace traditional organic solvents for metal dissolution or separation. To date, a thorough investigation of the physical properties biphasic TSIL-H(2)O systems and effects loading is lacking. In this work, change in liquid-liquid equilibrium [HBet][Tf(2)N]-H(2)O upon addition Nd(III) investigated by cloud-point measurements. The Nd(III), drops upper critical solution temperature over 20 °C. Further [HBet][Tf(2)N]-Nd(III) system...
Abstract Accelerator production of 225 Ac addresses the global supply deficiency currently inhibiting clinical trials from establishing Ac's therapeutic utility, provided that accelerator product is sufficient radionuclidic purity for patient use. Two proton activation experiments utilizing stacked foil technique between 40 and 200 MeV were employed to study likely co-formation radionuclides expected be especially challenging separate Ac. Foils assayed by nondestructive γ -spectroscopy α...
The carboxyl-functionalized phosphonium ionic liquid (IL), [HCTMP][Tf(2)N], enabled the directed nucleation of monomeric or dimeric uranyl(vi) compounds. This new IL is first which at room temperature and exhibits a wider electrochemical window lower melting point than its ammonium analogue.
Single crystals of Na(8)Pu(2)(O(2))(2)(CO(3))(6) x 12H(2)O, exhibiting bridging mu(2),eta(2)-O(2) ligands in unprecedented Pu(IV) dimeric units, were obtained at ambient temperature from an aqueous peroxide carbonate solution.
Abstract A process to separate technetium from uranium in a simulated solution resulting the extraction (UREX) was demonstrated using new chromatographic (EC) resin Eichrom Technologies. The Weak Base ECTM contains tertiary amine incorporated into macroporous bead support. provided good separation of pertechnetate 100 g/L uranyl(VI) nitrate representative UREX feed solution. appeared quite stable multiple uses. elution Tc substantially improved over previous anion exchangers used. eluted and...
Despite the wide range of applications α-hydroxyisobutyric acid (HIBA) in biochemical processes, pharmaceutical formulations, and group elemental separations lanthanides actinides, structures geometries lanthanide–HIBA complexes are still not well understood. We reacted HIBA with aqueous solution at pH = 5 synthesized 14 formula [Ln(HIBA)2(H2O)2](NO3)·H2O (Ln La (1), Ce (2), Pr (3), Nd (4), Sm (5), Eu (6), Gd (7), Tb (8), Dy (9), Ho (10), Er (11), Tm (12), Yb (13), Lu (14)), isolating single...
The radiolytic production of molecular hydrogen in the ionic liquids N-trimethyl-N-butylammonium bis(trifluoromethanesulfonyl)imide ([N1114][Tf2N]) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([emim][Tf2N]) has been examined with γ-rays, 2–10 MeV protons, 5–20 helium ions to determine functional dependence yield on particle track structure. Molecular is dominant gaseous radiolysis product from these liquids, yields γ-rays are 0.73 0.098 molecules per 100 eV energy...
Abstract Two organometallic 1D infinite coordination polymers and two monometallic complexes of thorium diazide have been synthesized characterized. Steric control these self‐assembled arrays, which are dense in nitrogen, has also demonstrated: chains can be circumvented by using steric bulk either at the metallocene or with a donor ligand wedge.
Single crystal structures of lanthanide carbonate and hydroxy-carbonate compounds have been previously reported in the literature, with majority these being extended one- to three-dimensional compounds. Very few isolated that contain molecular moieties, none for either erbium or dysprosium. crystals tetra-carbonate complexes, [C(NH2)3]5[Er(CO3)4]·11H2O (I) [C(NH2)3]4[Dy(CO3)4(H2O)](H3O)·13H2O (II), were from concentrated guanidinium solutions characterized by single X-ray diffraction...
Techniques to measure liquid level in containers and vessels non-invasively are of great interest for the manufacturing, chemical industries, energy sectors. Most commercial solutions use invasive techniques, which not always practical can lead unsafe conditions when measuring devices encounter high pressures or hazardous contents. In this study, a portable, non-invasive acoustic identification technique is developed. The relies on comprehensive analysis guided wave modes container walls...
Despite the discovery of actinide borohydride complexes over 80 years ago, no plutonium have been structurally validated using single-crystal X-ray diffraction (XRD). Here we describe Pu