A5017276331- Radioactive element chemistry and processing
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Frequency and Time Standards
- Crystallization and Solubility Studies
- Botulinum Toxin and Related Neurological Disorders
- Neurological disorders and treatments
- X-ray Diffraction in Crystallography
- Enhanced Oil Recovery Techniques
- Gold and Silver Nanoparticles Synthesis and Applications
- Nanomaterials for catalytic reactions
- Chemical Synthesis and Characterization
- Iron oxide chemistry and applications
- Atomic and Subatomic Physics Research
- Additive Manufacturing and 3D Printing Technologies
- Analytical chemistry methods development
- CO2 Sequestration and Geologic Interactions
- Microfluidic and Capillary Electrophoresis Applications
- Radioactive contamination and transfer
- Electrochemical Analysis and Applications
- Adsorption and biosorption for pollutant removal
- Seismic Waves and Analysis
- Advanced Nanomaterials in Catalysis
- Biosensors and Analytical Detection
- Microfluidic and Bio-sensing Technologies
- Advanced biosensing and bioanalysis techniques
Pacific Northwest National Laboratory
2013-2024
University of Bremen
2019-2023
SpaceTech (Germany)
2022
Universität Ulm
2022
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2021
Richland College
2015-2017
Battelle
2011-2017
University of California, San Francisco
2009
University of Oregon
2000-2007
Chulalongkorn University
2007
We have shown that superparamagnetic iron oxide (Fe3O4) nanoparticles with a surface functionalization of dimercaptosuccinic acid (DMSA) are an effective sorbent material for toxic soft metals such as Hg, Ag, Pb, Cd, and Tl, which effectively bind to the DMSA ligands As, binds lattices. The highly dispersible stable in solutions, large area (114 m2/g), high functional group content (1.8 mmol thiols/g). They attracted magnetic field can be separated from solution within minute 1.2 T magnet....
Unstable immiscible fluid displacement in porous media affects geological carbon sequestration, enhanced oil recovery, and groundwater contamination by non-aqueous phase liquids. Characterization of processes at the pore scale is important to better understand macroscopic continuum scale. A series experiments was conducted investigate impacts viscous capillary forces on stability saturation distributions a homogeneous water-wet network micromodel with precisely microfabricated structures....
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTImproved Synthesis of Small (dCORE ≈ 1.5 nm) Phosphine-Stabilized Gold NanoparticlesWalter W. Weare, Scott M. Reed, Marvin G. Warner, and James E. HutchisonView Author Information Department Chemistry Materials Science Institute University Oregon, Eugene, Oregon 97403-1253 Cite this: J. Am. Chem. Soc. 2000, 122, 51, 12890–12891Publication Date (Web):December 27, 2000Publication History Received20 July 2000Published online27 December inissue 1...
A convenient preparation is reported for a series of functionalized, thiol-stabilized gold particles with subnanometer core diameters (dCORE = 0.8 ± 0.2 nm). The produces previously inaccessible materials through ligand exchange reactions phosphine-stabilized precursor, Au11(PPh3)8Cl3, ω-functionalized alkanethiols. Convenient access to these new prerequisite the detailed study electronic and optical properties investigation utility building blocks in nanoscale devices. Preliminary...
The use of air-water, θ(wa), or air-liquid contact angles is customary in surface science, while oil-water angles, θ(ow), are paramount importance subsurface multiphase flow phenomena including petroleum recovery, nonaqueous phase liquid fate and transport, geological carbon sequestration. In this paper we determine both the air-water silica surfaces modified with a diverse selection silanes, using hexadecane as oil. silanes included alkylsilanes, alkylarylsilanes, alkyl aryl groups that...
Permeability contrasts exist in multilayer geological formations under consideration for carbon sequestration. To improve our understanding of heterogeneous pore-scale displacements, liquid CO2 (LCO2)–water displacement was evaluated a pore network micromodel with two distinct permeability zones. Due to the low viscosity ratio (logM = −1.1), unstable occurred at all injection rates over 2 orders magnitude. LCO2 displaced water only high zone mechanism shifting from capillary fingering...
Abstract We describe the synthesis and characterization of high‐performance, superparamagnetic, iron oxide nanoparticle‐based, heavy metal sorbents, which demonstrate excellent affinity for separation metals in contaminated water systems (i.e., spiked Columbia River water). The magnetic nanoparticle sorbents were prepared from an easy‐to‐synthesize precursor, followed by a simple, one‐step ligand exchange reaction to introduce surface that is specific or class contaminants. engineered have...
A method for tuning the analyte affinity of magnetic, inorganic nanostructured sorbents heavy metal contaminants is described. The manganese-doped iron oxide nanoparticle have a remarkably high compared to precursor material. Sorbent can be tuned toward an interest simply by adjustment dopant quantity. results show that following Mn doping process there large increase in and capacity metals (i.e., Co, Ni, Zn, As, Ag, Cd, Hg, Tl). Capacity measurements were carried out removal cadmium from...
Surface-functionalized nanoporous silica, often referred to as self-assembled monolayers on mesoporous supports (SAMMS), has previously demonstrated the ability serve very effective heavy metal sorbents in a range of aquatic and environmental systems, suggesting that they may be advantageously utilized for biomedical applications such chelation therapy. Herein we evaluate surface chemistries capture from biological fluids, various facets materials' biocompatibility, suitability these...
The Pacific Northwest National Laboratory (PNNL) is evaluating the performance of adsorption materials to extract uranium from natural seawater. Testing consists measurements and other elements seawater as a function time using flow-through columns recirculating flume determine adsorbent capacity kinetics. amidoxime-based polymer AF1, produced by Oak Ridge (ORNL), had 56-day 3.9 ± 0.2 g U/kg material, saturation 5.4 half-saturation 23 2 days. ORNL AF1 has very high affinity for uranium,...
An anti-counterfeiting method is introduced by doping optically-active nanomaterials into printed parts, non-destructively measuring the part's chemical signatures arising from taggants, and linking resulting signature data to a blockchain.
Urine is universally recognized as one of the best non-invasive matrices for biomonitoring exposure to a broad range xenobiotics, including toxic metals. Detection metal ions in urine has been problematic due protein competition and electrode fouling. For direct, simple, field-deployable monitoring urinary Pb, electrochemical sensors employing superparamagnetic iron oxide (Fe3O4) nanoparticles with surface functionalization dimercaptosuccinic acid (DMSA) developed. The detection involves...
We report the production of flexible, highly-conductive poly(vinylidene fluoride) (PVDF) and multi-walled carbon nanotube (MWCNT) composites as filament feedstock for 3D printing. This account further describes, first time, fused deposition modelling (FDM) derived 3D-printed objects with chemiresistive properties in response to volatile organic compounds. The typically prohibitive thermal expansion die swell characteristics PVDF were minimized by presence MWCNTs enabling straightforward...
The ability to collect uranium from seawater offers the potential for a nearly limitless fuel supply nuclear energy.
Microgravity eases several constraints limiting experiments with ultracold and condensed atoms on ground. It enables extended times of flight without suspension eliminates the gravitational sag for trapped atoms. These advantages motivated numerous initiatives to adapt operate experimental setups microgravity platforms. We describe design payload, motivations choices, capabilities Bose-Einstein Condensate Cold Atom Laboratory (BECCAL), a NASA-DLR collaboration. BECCAL builds heritage...
A general synthetic approach leading to well-defined, water-soluble gold nanoparticles is described that involves a simple, interfacial ligand exchange reaction between 1.4 nm phosphine-passivated precursor and an anionic or cationic thiol-containing ligand. We demonstrate the utility of this route by synthesizing are stabilized either (2-mercaptoethanesulfonate), (2-(dimethylamino)ethanethiol hydrochloride), mixture both ionic phosphine ligands. Although course process depends on nature...
Abstract Combining octyl(phenyl)-N,N-diisobutyl-carbamoylmethyl-phosphine oxide (CMPO) and bis-(2-ethylhexyl) phosphoric acid (HDEHP) into a single process solvent for separating transuranic elements from liquid high-level waste is explored. Co-extraction of americium the lanthanide nitric solution possible with mixture consisting 0.1 M CMPO plus 1 HDEHP in n-dodecane. Switching aqueous-phase chemistry to citrate-buffered diethylene triamine pentaacetic (DTPA) allows selective stripping...
A non-oxido V(<sc>v</sc>) complex with glutaroimide-dioxime (H<sub>3</sub>L), a ligand for recovering uranium from seawater, was synthesized aqueous solution as Na[V(L)<sub>2</sub>]·2H<sub>2</sub>O, and the structure determined by X-ray diffraction.
Methods to covalently conjugate Alexa Fluor dyes cellulose nanocrystals, at limiting amounts that retain the overall structure of nanocrystals as model materials, were developed using two approaches. In first, aldehyde groups are created on surfaces by reaction with sodium periodate, a well-known for oxidizing vicinal diols create dialdehyde structures. Reductive amination reactions then applied bind terminal amino-groups linker section. absence reductive step, dye washes out nanocrystal...
Wettability is a key parameter influencing capillary pressures, permeabilities, fingering mechanisms, and saturations in multiphase flow processes within porous media. Glass‐covered silicon micromodels provide precise structures which pore‐scale displacement can be visualized. The wettability of glass surfaces modified by silanization. However, similar treatments silica using the same silane do not necessarily yield as determined oil‐water contact angle. In this study, surface cleaning...
The ability to collect uranium from seawater offers the potential for a long-term green fuel supply nuclear energy. However, extraction of uranium, and other trace minerals, is challenging because high ionic strength low mineral concentrations in seawater. Herein we evaluate use nanostructured metal oxide sorbents collection recovery Chemical affinity, chemical adsorption capacity, uptake kinetics sorbent materials were evaluated. Materials with higher surface area clearly produced better...
Multifunctional organic molecules represent an interesting challenge for nanoparticle functionalization due to the potential undesirable interactions between substrate material and variable functionalities, making it difficult control final orientation of ligand. In present study, UV-induced thiol−ene click chemistry has been utilized as a means directed bifunctional ligands on iron oxide surface. Allyl diphosphonic acid ligand was covalently deposited surface thiol-presenting nanoparticles...
In this paper, we present a convenient and reliable method to organize small gold nanoparticles (d(CORE) = 1.5 nm) into linear chains with precisely controlled interparticle spacing over range of 1.5-2.8 nm through biomolecular nanolithography. Controlling the feature separations 1 few nanometers angstrom-level precision is key requirement in electronic optical applications nanostructures tune properties manipulate interactions between neighboring structures. Here, are formed solution by...