Search NASA⌕ Search

SEARCH · Search NASA

Results for “lanthanide binding”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2

Modulating metal-centered dimerization of a lanthanide chaperone protein for separation of light lanthanides

Elucidating details of biology’s selective uptake and trafficking of rare earth elements, particularly the lanthanides, has the potential to inspire sustainable biomolecular separations of these essential metals for myriad modern technologies. Here, we biochemically and structurally characterize Methylobacterium (Methylorubrum) extorquens LanD, a periplasmic protein from a bacterial gene cluster for lanthanide uptake. This protein provides only four ligands at its surface-exposed lanthanide-binding site, allowing for metal-centered protein dimerization that favors the largest lanthanide, La III . However, the monomer prefers Nd III and Sm III , which are disfavored lanthanides for cellular utilization. Structure-guided mutagenesis of a metal-ligand and an outer-sphere residue weakens metal binding to the LanD monomer and enhances dimerization for Pr III and Nd III by 100-fold. Selective dimerization enriches high-value Pr III and Nd III relative to low-value La III and Ce III in an all-aqueous process, achieving higher separation factors than lanmodulins and comparable or better separation factors than common industrial extractants. Finally, we show that LanD interacts with lanmodulin (LanM), a previously characterized periplasmic protein that shares LanD’s preference for Nd III and Sm III . Our results suggest that LanD’s unusual metal-binding site transfers less-desirable lanthanides to LanM to siphon them away from the pathway for cytosolic import. The properties of LanD show how relatively weak chelators can achieve high selectivity, and they form the basis for the design of protein dimers for separation of adjacent lanthanide pairs and other metal ions.

lanthanide biochemistry↗

Rare Earth Desorption Test with Citrate and Bicarbonate

LBT (lanthanide binding tag) cells were grown overnight in LB media with 0.05% Amp. 1:100 subculture taken from overnights, grown for 2 hours. LBT was induced with 0.002% arabinose added for 3 hours. REE adsorption was done by combining 350 ul (0.25% 1M MES, 12.5 uM Tb, and 12.5 uM La or Cu in sterile DI water) and 350 ul (LBT cells with OD = 1 in 10 mM MES), reacted for approx. 30 min. Following adsorption, citrate and bicarbonate solutions were used in desorption to recover rare earth from cell surface, and to further separate REE from non-REEs. The samples were then centrifuged and a fraction of the supernatant was collected for ICP-MS analysis.

15 GEOTHERMAL ENERGY↗

Fabrication of Biofunctionalized PVA/PEI Nanofibers for Rare Earth Element Extraction from Coal Mine Tailings

The need for rare earth elements (REEs) for new technology is becoming increasingly stiff with demand at a record high. Biological ligands like lanmodulin and lanthanide binding tags (LBT) have gained noticeable attention for their selective extraction of valuable lanthanide metals in aqueous solution. Building on previous work using microbeads as the extraction media, we propose that nanofibers can improve extraction capabilities. Nanofibers could provide more efficient flow and higher extraction yields due to their high surface area to volume ratio. Relying on thiolmaleimide click chemistry as the biological ligand immobilization route, electrospinning as the nanofiber manufacturing method, and numerous characterization techniques, we produced electrospinning polymer solutions and nanofibers with a maximum neodymium adsorbent capacity of 12.1 μmol/g of extraction media immobilized with LBT. Although the prior work produced an extraction media with an equivalent capacity of ~40 μmol/g, the electrospinning process is much more economical and scalable. This work paves the way for an industrially relevant, environmentally-friendly REE extraction material. Further work is required to produce higher quality nanofibers, to investigate common ion interference with REE adsorbance, and to scale production up to a relevant scale.

01 COAL, LIGNITE, AND PEAT↗

Characterization of U-Zr fuel with alloying additive Sb for immobilizing fission product lanthanides

Fission product lanthanides can migrate to the fuel periphery and enhance fuel-cladding chemical interaction (FCCI). Adding Sb into the fuel alloy to bind lanthanides and thus to prevent lanthanides from migration has been proposed. The U-Zr fuel alloys were fabricated with compositions of U-10Zr-4.1Sb, U-10Zr-4.1Sb-4Ce, U-10Zr-2.07Sb, and U-10Zr-2.07Sb-2Ce wt.% by arc melting, and analyzed under scanning electron microscope (SEM) for the microstructure and elemental compositions. In the Ce-free alloy, Sb was found in Sb-Zr precipitates; while in the Ce-contained alloy, Sb was found in the form of intermetallic compounds Ce 4 Sb 3 and Ce 2 Sb without any Sb-Zr precipitates. In conclusion, antimony has the preference to bind Ce over Zr, indicating Sb can effectively prevent Ce interaction with Fe to the extent. Cerium is bound to Sb and no ternary intermetallic Ce-Sb-Zr compound was found.

36 MATERIALS SCIENCE↗

Diffusion Couple Investigations of Ce-Sb Compounds with Fe

Fission product lanthanides can migrate to the fuel periphery and react with cladding, causing fuel-cladding chemical interaction (FCCI). Adding a fuel additive dopant, such as Sb, can bind lanthanides, such as Ce, into metallic compounds to prevent migration. The present study focuses on the thermodynamic stability of Ce-Sb compounds when in contact with the major cladding constituent Fe by conducting diffusion couple tests. Here, Ce-Sb compounds have shown high thermodynamic stability as they did not react with Fe; when Fe-Sb compounds contacted with Ce, Sb was separated out of the Fe-Sb compounds and formed the higher stability Ce-Sb compounds.

36 MATERIALS SCIENCE↗

Selective Biosorption of Valuable Rare Earth Elements Among Co-Occurring Lanthanides

To meet the increasing demand for rare earth elements (REEs) essential for low carbon-intensity energy technologies, new methods are needed for selective REE extraction from unconventional resources. Only a few REEs have significant economic value, but isolation of target rare earths from co-occurring lanthanides is challenging due to their similar chemical behavior. We present a novel approach to enhance separation of specific REEs from lanthanide mixtures. Escherichia coli cells engineered with lanthanide binding tags (LBTs) were immobilized in nonadsorbing, permeable polyethylene glycol diacrylate beads and packed into continuous flow, fixed-bed columns. Breakthrough of 15 rare earths in the +3 oxidation state resulted in notable differences in adsorption selectivity, with greatest separation between europium (Eu) and lanthanum (La) due to competitive displacement. REE adsorption onto fixed-bed columns was predicted by coupling a surface complexation model to a calibrated one-dimensional dual porosity transport model that accounts for interbead advective and intrabead diffusive transport. A tradeoff between high-abundance, low-affinity native carboxyl sites and low-abundance, high-affinity engineered LBT sites dictates process recovery efficiency and selectivity. Key chemical and operational parameters are identified to maximize selective extraction of high-value lanthanides, achieving a threefold enhancement of Eu recovery relative to La in a mixed REE solution.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Enhanced rare-earth separation with a metal-sensitive lanmodulin dimer

Technologically critical rare-earth elements are notoriously difficult to separate, owing to their subtle differences in ionic radius and coordination number. The natural lanthanide-binding protein lanmodulin (LanM) is a sustainable alternative to conventional solvent-extraction-based separation. Here we characterize a new LanM, from Hansschlegelia quercus (Hans-LanM), with an oligomeric state sensitive to rare-earth ionic radius, the lanthanum(III)-induced dimer being >100-fold tighter than the dysprosium(III)-induced dimer. X-ray crystal structures illustrate how picometre-scale differences in radius between lanthanum(III) and dysprosium(III) are propagated to Hans-LanM’s quaternary structure through a carboxylate shift that rearranges a second-sphere hydrogen-bonding network. Comparison to the prototypal LanM from Methylorubrum extorquens reveals distinct metal coordination strategies, rationalizing Hans-LanM’s greater selectivity within the rare-earth elements. Finally, structure-guided mutagenesis of a key residue at the Hans-LanM dimer interface modulates dimerization in solution and enables single-stage, column-based separation of a neodymium(III)/dysprosium(III) mixture to >98% individual element purities. This work showcases the natural diversity of selective lanthanide recognition motifs, and it reveals rare-earth-sensitive dimerization as a biological principle by which to tune the performance of biomolecule-based separation processes.

36 MATERIALS SCIENCE↗

Postirradiation characterization of palladium as an additive for fuel cladding chemical interaction mitigation in metallic fuel

This work describes the microstructural and elemental characterization of irradiated metallic fuels containing palladium as an additive. The use of additives has been proposed to control Fuel-Cladding Chemical Interaction (FCCI) and thus to promote higher fuel utilization (i.e., higher burnup). In this work, Pd has been investigated as a potential additive to metallic fuel to bind lanthanides, impeding their migration and attack on the cladding. The influence of Pd on the microstructure, chemistry and performance of metallic fuel has been characterized via scanning electron microscopy for two metallic fuel designs—namely, annular and solid fuel. Pd was observed to play an important role in the chemistry of the fuel. Indeed, the addition of Pd leads to the formation of new phases. Pd was detected to combine not only with the lanthanides, as intended, but also with Zr, a main element of the fuel matrix. While Pd proved to be effective in preventing lanthanide migration and their attack on the cladding, the Pd-Zr compound may potentially lead to other unexpected fuel-performance issues, such as the formation of low-melting point phases and increased unalloyed U available for FCCI interaction with Fe in the cladding. Even the increase of Zr to 13wt%. did not completely mitigate this adverse phenomenon generated by the Pd-Zr interaction. Furthermore, the efficacy of using this additive needs further investigation.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Recovery of Rare Earth Elements from Low-Grade Feedstock Leachates Using Engineered Bacteria

The use of biomass for sorption of rare earth elements (REEs) for bioremediation and biomining applications has been the subject of many recent investigations. However, REE adsorption by bioengineered systems has been scarcely documented, and rarely tested with complex natural feedstocks. In this study, we engineered E. coli cells for enhanced cell surface-mediated extraction of REEs. Using Lpp-OmpA as an anchor, up to 16 copies of a Lanthanide binding tag (LBT) per OmpA protein were displayed on the E. coli cell surface, resulting in a 2-fold increase in Tb adsorption capacity compared to control cells. To test the efficacy of engineered E. coli cells to extract REEs from complex source materials, biosorption was performed with leachates from two mine tailings and two rare earth deposits. Although control E. coli cells exhibited preferential adsorption of REEs over most metals, functionalization of the cell surface with LBT yielded several notable advantages. First, the efficiency of REE adsorption from all tested leachates was enhanced with distribution coefficients for individual REEs increased by 2-10 fold. Second, although, Cu, Al, Ga and Pb were found to be the best competitors for REE binding to the E. coli cell surface, LBT-display enhanced the cell surface affinity for REEs over all non-REEs except Cu. Third, LBT-display systematically enhanced the affinity of the cell surface for REEs as a function of decreasing atomic radii, providing a means to separate high value HREEs such as Dy and Tb from more common LREEs such as La. Altogether, our results demonstrate that REE biosorption of high efficiency and selectivity can be achieved by engineering the native bacterial surface.

60 APPLIED LIFE SCIENCES↗

Recovery of Rare Earth Elements from Geothermal Fluids through Bacterial Cell Surface Adsorption

The increasing demand for rare earth elements (REEs) in the modern economy motivates the development of novel strategies for cost-effective REE recovery from nontraditional feedstocks. We previously engineered E. coli to express lanthanide binding tags on the cell surface, which increased the REE biosorption capacity and selectivity. Here we examined how REE adsorption by the engineered E. coli is affected by various geochemical factors relevant to geothermal fluids, including total dissolved solids (TDS), temperature, pH, and the presence of specific competing metals. REE biosorption is robust to TDS, with high REE recovery efficiency and selectivity observed with TDS as high as 165,000 ppm. Among several metals tested, U, Al, and Pb were found to be the most competitive, causing >25% reduction in REE biosorption when present at concentrations ~3- to 11-fold higher than the REEs. Optimal REE biosorption occurred between pH 5-6, and sorption capacity was reduced by ~65% at pH 2. REE recovery efficiency and selectivity increased as a function of temperature up to ~70 °C due to the thermodynamic properties of metal complexation on the bacterial surface. Ultimately, these data define the optimal and boundary conditions for biosorption and demonstrate its potential utility for selective REE recovery from geofluids.

58 GEOSCIENCES↗

Microbe Encapsulation for Selective Rare-Earth Recovery from Electronic Waste Leachates

Rare earth elements (REEs) are indispensable components of many green technologies and of increasing demand globally. However, refining REEs from raw materials using current technologies is energy intensive and enviromentally damaging. Here, we describe the development of a novel biosorption-based flow-through process for selective REE recovery from electronic wastes. An Escherichia coli strain previously engineered to display lanthanide-binding tags on the cell surface was encapsulated within a permeable polyethylene glycol diacrylate (PEGDA) hydrogel at high cell density using an emulsion process. This microbe bead adsorbent contained a homogenous distribution of cells whose surface functional groups remained accessible and effective for selective REE adsorption. The microbe beads were packed into fixed-bed columns, and breakthrough experiments demonstrated effective Nd extraction at a flow velocity of up to 3 m/h at pH 4–6. The microbe bead columns were stable for reuse, retaining 85% of the adsorption capacity after nine consecutive adsorption/desorption cycles. A bench-scale breakthrough curve with a NdFeB magnet leachate revealed a two-bed volume increase in breakthrough points for REEs compared to non-REE impurities and 97% REE purity of the adsorbed fraction upon breakthrough. These results demonstrate that the microbe beads are capable of repeatedly separating REEs from non-REE metals in a column system, paving the way for a biomass-based REE recovery system.

Biological and medical sciences↗

Polymer Tacticity Effects in Polymer–Lanthanide Chelation Thermodynamics

Metal-chelating polymers are critical components in numerous applications. However, despite the known influence of polymer tacticity on both bulk and solution properties, most materials used in metal-chelation applications are atactic. Here, we investigate the relationship between polymer tacticity and polymer–lanthanide interactions in aqueous solution. We synthesized a series of five poly(methacrylic acid)s with systematic variations in tacticity (20–99% m diads) and used isothermal titration calorimetry to measure the thermodynamics of lanthanide binding to each material (ΔH, ΔG, ΔS, K a , and stoichiometry). We observed enthalpy–entropy compensation across this tacticity series, finding that both |ΔH| and |ΔS| decreased with decreasing m diad content while ΔG remained similar. Molecular dynamics simulations of the polymer–metal interactions revealed that the observed differences in binding thermodynamics may be largely ascribed to differences in polymer flexibility. Furthermore, these combined experimental and computational results demonstrate that metal binding can be influenced by altering the polymer stereochemistry, ultimately influencing the design of more efficient metal-chelating materials.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Experimental Investigation of FCCI Using Diffusion Couple Test Between UZr Fuel with Sb Additive and Cladding

Alloying additions are introduced into U-Zr fuel in order to bind lanthanides (e.g., cerium) and prevent their migration to the fuel-cladding interface. Antimony (Sb) is being investigated as a candidate additive. The present study focuses on the diffusion couple behavior of U-10Zr (wt%) alloy with Sb against cladding (iron or HT9) at 640°C. The diffusion cross sections were analyzed using a scanning electron microscope and X-ray diffraction. Zr-rind was found at the interface of the fuel alloy, Sb was found to be bound in Sb-Zr precipitates or Sb-Ce precipitates, and no reaction was found between Sb precipitates and the cladding materials.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Rare Earth Element Biomining from the Great Salt Lake Brine Using Engineered E. Coli

This data describes rare earth element adsorption onto E. coli cells engineered to express a lanthanide binding tag (LBT). We used a Great Salt Lake synthetic solution as the background matrix with Tb added to 1-10,000 ppb, concentrations much lower than the competing ions present. Our results showed that Tb binds to LBT, even in the presence of high concentrations of competing metals. We also tested REE adsorption at elevated temperatures (up to 100 degrees Celsius), and observed that Tb adsorption increases with temperature of to 70 degrees Celsius, and then remains constant until 100 degrees Celsius. Data analyses were performed using an ICP-MS at UCSC.

15 GEOTHERMAL ENERGY↗

First Examination of Irradiated Fuel with Pulsed Neutrons at LANSCE (Preliminary Results)

We present preliminary results on the characterization of an irradiated U-lOZr-lPd fuel sample that was prepared from the irradiated AFC-3A-R5A sample. U-lOZr metallic fuels are researched as host materials for potential transmutation fuels and the addition of palladium strives to bind lanthanides, thus preventing fuel-cladding chemical interactions (FCCI). These interactions limit the lifetime of metallic fuels and are caused by migration of lanthanide fission products to the periphery of the fuel slug, where they start to interact with the D9 or HT9 steel cladding, ultimately leading to failure of the mechanical integrity of the cladding. Neutrons offer bulk characterization of irradiated materials for which X-ray tomography methods are not suitable due to the immense gamma background emitted from the samples. In particular pulsed neutrons provide information from the ability to resolve the neutron energy using their time-of-flight and thus the potential to utilize neutron absorption resonance to characterize the spatial distribution of isotopes. This, in turn, may allow to characterize the distribution of fission and neutron capture products non-destructively and may ultimately be applied to the bulk of an irradiation capsule prior to destructive post-irradiation examination to identify regions of interest. To allow the characterization of entire irradiation capsules, a cask is under development in the advanced post-irradiation work package at LANL and progress on this development was reported elsewhere. In parallel, an irradiated U-lOZr-lPd sample cut from the AFC-3AR5A irradiation was shipped to LANL and will be fully characterized with an NSUF funded rapid turnaround experiment (RTE) in the 2020 LANSCE run cycle. The sample emits at a dose rate of ~3R/hr on contact and is therefore manageable with remote handling, without requiring a cask. The disk-shaped material is larger than samples prepared for analysis using electron or X-ray methods and is therefore an intermediate step towards characterization of bulk samples at LANSCE. However, since it covers the full diameter of the irradiated fuel slug, some insight on redistribution of elements, spatially resolved information on microstructure, e.g. phase composition and texture, will be possible using the pulsed neutron-based methods developed for fuel characterization at LANSCE. This report describes the development of procedures to handle the sample at LANSCE as well as preliminary data and results from tests conducted in December 2019 on the energy-resolved neutron imaging (ERNI) beam line at flight path 5 and the high pressure-preferred orientation diffractometer (HIPPO) at LANSCE. This effort is a collaboration between LANL, INL, and ORNL. To compare our capabilities with prior work, we present an overview of previously reported bulk characterization of irradiated or spent fuels. The overview addresses neutron diffraction and neutron absorption resonance spectroscopy, both of which have only few reported applications on irradiated or spent nuclear fuel, as well as neutron radiography. This literature review was already described in a previous report but is repeated here to put our current efforts in context of previous work.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Living Filter Designs for In-Line Recovery and Sorting of Critical materials

This project explored “bio-mining” of critical materials from electronic waste (E-waste) streams by developing living filters arrays capable of recovering these materials, focusing on the platinum group metals (PGMs) and rare earth elements (REEs). While highly toxic, E-waste is considered a valuable “urban mine” as it contains critical materials such as PGMs and REEs with orders of magnitude higher purity than the richest ores. The aim of the project was to: (1) develop mechanically robust, silk-based biomaterial filtration membranes that can capture REEs from dilute aqueous waste; (2) design and build 3D bioprinted living filters containing encapsulated electrochemically active bacteria (EAB) capable of bio-reducing PGMs and recovering them from waste streams; and (3) constructing combined living filter arrays using both components to efficiently capture REE and PGM from the same waste stream. The developed silk-based filtration membranes were self-assembled using silk-nanofibrils (SNFs) derived from silkworm (Bombyx mori) cocoons in conjunction with recombinant silk-elastin-like proteins (SELPs), which contained lanthanide-binding peptide tags (LBTs) with a high affinity and specificity towards REEs. These 100% biodegradable protein-based membranes were capable of recovering up to 85% of model REE ions (Tb 3+ ) filtered through the membrane, with ~50% recovery achieved in the presence of high concentrations (100X) of common interfering metals (Ca 2+ , Cu 2+ , Fe 3+ , Zn 2+ ). REE captured by the membranes were easily recovered by applying a low pH desorption buffer. The membranes also demonstrated substantial reusability, with only a 30% loss in binding capacity after 4 cycles of REE binding and recovery. To recover the PGMs, we created a bottom-up assembling strategy to construct a living hydrogel composed of a seamlessly integrated living catalyst, Shewanella loihica PV-4 (PV-4), for metal reduction, and their structural and functional linkers, bio-reduced graphene oxide (B-rGO). This hydrogel demonstrated a close to 90% recovery of model metal ions, Pd, from a simulated e-waste leaching stream with minimum-to-no biomass production. It’s also worth noting that the Pd recovery is initiated immediately after the introduction of living hydrogel, compared to conventional biocarriers that required start-up times within hours to days. Overall, these living hydrogels demonstrated superior bioactivity, structural integrity, and agility over existing biocarriers, which offers extensive opportunities to advance the biological metal recovery with unparallel efficiency, reduced energy/material consumption, and minimal environmental impact.

36 MATERIALS SCIENCE↗

Improving Self-Driving Labs: Quantifying System-Level Experiment Repeatability and Broadening Instrument-Level Compatibility

Modular Autonomous Research System (MARS) is a self-driving laboratory (SDL) which performs wet-lab science with peptide-lanthanide combinations in an automated and, ultimately, an autonomous manner to aid in soil analysis for domestic lithium mining. Autonomous experimentation involves automated experimentation, experiment planning, and active learning. MARS consists of a 6-axis robotic arm (UR5e) on a linear rail, pipette robots (Opentrons 2), and microplate readers. These components transport, operate on, and collect data with chemical solutions in standard labware. For effective autonomy, MARS must perform system-level labware operations repeatably, plan experiments autonomously, and be portable between research-domains. Repeatability is evaluated by labware placement precision, such that future operations can properly locate labware, as well as the elapsed time, so that low variance mean estimates of experiment duration can inform high-level researcher decision making. Autonomous experiment planning is the next step to decouple experimentation from human management; however, there is a conflict between the ideal system-level experiment goals and the constraints imposed by instruments’ limitations. Sub-domain portability is a long-term goal to extend MARS’ research beyond the chemistry of peptide-lanthanide binding to other sub-domains without having to invest significant overhead to system retrofitting. To address these goals, we manually trained the robotic arm labware placement and modelled statistical failurerate and uncertainty Additionally, we benchmarked the duration and variance of each experiment sub-operation as a heuristic for research decision making. Next, we use a parameterized geometric program (PGP) approach to design experiments that optimize system-level objectives and satisfy instrument-level constraints. Lastly, we proposed a Python framework to maximize MARS’ extensibility to other scientific sub-domains through a JSON-based experiment specification.

36 MATERIALS SCIENCE↗