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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.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Highly Efficient Removal of Lead Ions from Aqueous Solutions Using Chitosan/Rice Husk Ash/Nano Alumina with a Focus on Optimization by Response Surface Methodology: Isotherm, Kinetic, and Thermodynamic Studies

In the present study, an adsorbent named chitosan/rice husk ash/nano-γ alumina was prepared and used for the removal of lead ions from aqueous solutions. It was characterized by FESEM, FTIR, XRD, and BET. The important and interactive effects of some considered parameters, such as the initial lead ion concentration, pH, adsorbent mass and contact time, were estimated and optimized by using the central composite design (CCD). The Maximum adsorption efficiency of lead ions under optimum conditions, including the pH of 5, adsorbent mass of 0.01 g, the initial lead ion concentration of 30 ppm, and the contact time of 105 min, was achieved to be 90.98%. The adsorption kinetic was consistent with the pseudo-second-order model (R{sup 2} = 0.9967). The lead adsorption isotherms were well fitted to the Langmuir model, indicating the maximum adsorption capacity of 181.82 mg g{sup −1}. Thermodynamic parameters (R{sup 2}: 0.9200, ΔH°: − 22871.81 kJ mol{sup −1}, ΔG{sup °}: − 10.63 kJ mol{sup −1}, and ΔS{sup °}: 118.37 kJ mol{sup −1} K{sup −1}) were calculated and indicating adsorption process was exothermic and spontaneous in the temperature range of 283.15–313.15 k. The maintenance above 70% capacity of the adsorbent was observed by the regeneration study of chitosan/rice husk ash/nano-γ alumina after six cycles. Comparison of adsorption efficiency of the studied adsorbent and other adsorbents in the removal of lead ions was also done in this paper. Consequently, the excellent properties of the presented nanocomposite could make it an ideal adsorbent for the removal of lead ions from aqueous solutions. Graphical Abstract: .

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2019

Synthesis of calcium carbonate nanoparticles in erythrocytes enables efficient removal of extracellular lead ions

The “cyborg cells”, living cells with built-in nanoscaffolds, which could integrate the biological function of the cells with the functionality of nanomaterials, have been rarely explored. Here we report a method to construct “cyborg erythrocytes” through the in situ reaction of exogenous calcium and carbonate ions to generate calcium carbonate nanodots inside erythrocytes. The intracellular calcium carbonate nanodots combined with proteins are hidden under the membrane of erythrocytes, which can restrict migration and unexpected accumulation of nanodots in the body, improving the biosecurity of the nanodots. Most importantly, the calcium carbonate nanodots not only do not bring adverse effects on the nature of erythrocytes, but also endow erythrocytes with new properties. The in vitro and in vivo results show that the “cyborg erythrocytes” can remove 80% of lead ions in a blood poisoning model and reduce the lead level in the kidney and liver of mice through a precipitation transformation mechanism.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Halide Heterogeneity Affects Local Charge Carrier Dynamics in Mixed-Ion Lead Perovskite Thin Films

The mechanisms and elemental composition that form the basis for the improved optical and electronic properties in mixed-ion perovskite solar cells are still not well understood compared to standard methylammonium lead triiodide perovskite devices. Here, we use synchrotron-based X-ray fluorescence to map the composition of perovskite thin films. To get insights into the elemental distribution during film growth, we fabricate films with three different thicknesses. To create a link between the composition and the electronic properties, we perform Kelvin probe force microscopy and time-resolved photoluminescence spectroscopy. We find that the elemental composition is highly dependent on the film thickness, in particular, that the I/Pb ratio is altered for single grains based on the film thickness. The difference in the I/Pb ratio reveals to be the root cause for the underlying difference in film lifetime and defect density influencing charge carrier dynamics. Our results provide an in-depth analysis approach combining macro- and nanoscale techniques to shed light onto the fundamental processes which help to further engineer perovskite thin films and improve device efficiencies.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Selective single-atom adsorption for precision separation of lead ions in tap water via capacitive deionization

Capacitive deionization (CDI) offers a cost-effective and low-energy method for selective removal of Pb 2+ from drinking water. Modifying CDI electrode surfaces with functional groups presents a versatile approach to enhancing selective ion adsorption capacity. However, a comprehensive understanding of the selectivity and removal efficiency of Pb 2+ among diverse functional groups remains unexplored. Here, we investigated the effects of different functional groups (-SH, -COOH, and -NH 2 ) attached to the graphene oxide (GO) electrode surfaces on Pb 2+ selectivity and removal efficiency. Surprisingly, GO-COOH demonstrated single-atom adsorption of Pb 2+ , displaying superior removal efficiency and selectivity compared with -SH and -NH 2 , although -SH possesses significant chelation capability for Pb 2+ . Both density functional theory (DFT) calculations and X-ray pair distribution function (PDF) analyses confirmed that Pb 2+ exhibits a theoretically higher affinity to -COOH. Further, this research deepens our understanding of the interactions between functional groups and heavy metal ions, enabling selective and rapid separation of target cations for water purification.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Chemoresponsive Nanofluidic Pump That Turns Off in the Presence of Lead Ion

There are many applications that require the integration of a pump and a chemical sensor so that the solution being pumped can be analyzed in real time for a specific chemical species and the flow adjusted according to the measured concentration of that species. In this paper, we describe an alternative strategy: a chemoresponsive pump where a single device acts as both the sensor and pump simultaneously. We demonstrate this concept with a nanofluidic Pb 2+ -responsive pump that uses electroosmotic flow as the pumping technology, and a Pb 2+ -binding ionophore that allows the device to selectively respond to Pb 2+ . The pump yields high flow rates at low Pb 2+ concentrations (<1 μM), but flow rate decreases with concentrations above this threshold and ultimately goes to zero at concentrations above 100 μM.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Efficient Removal of Lead Ions from Aqueous Media Using Sustainable Sources Based on Marine Algae

The goal of this project is to explore a new method to efficiently remove Pb(II) ions from water by processing Undaria pinnatifida into immobilized beads using sodium alginate and calcium chloride. The resulting biosorbent was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). Using immobilized U. pinnatifida, we investigated the effect of various factors on Pb(II) ion removal efficiency such as temperature, pH, ionic strength, time, and underlying biosorption mechanisms. For Pb(II) ion biosorption studies, Pb(II) ion biosorption data were obtained and analyzed using Langmuir and Freundlich adsorption models. It is found that the maximum Pb(II) ion adsorption capacity (X m ) of U. pinnatifida was estimated to be ~5 times greater than that of activated carbon, indicating the superior Pb(II) ion removal capability of U. pinnatifida compared to activated carbon. In addition, a thermodynamic study indicates that biosorption processes are found to be endothermic and an increase in the Pb(II) ion solution temperature provides a more preferential reaction toward Pb(II) ion biosorption.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

A portable and reusable sensor system based on graphene for real-time and sensitive detection of lead ions in water

Long-term exposure to Pb 2+ can cause irreversible damage to the nervous, cardiovascular, and reproductive systems. Therefore, developing a fast and sensitive detection system capable of monitoring minuscule concentrations of Pb 2+ is essential. In this study, we demonstrated a fully portable sensor system enabling rapid, sensitive, and real-time monitoring of Pb 2+ . The sensor system adopted the remote-gate field-effect transistor (RGFET) detection scheme and was easy to operate, even for non-experts. The sensor system comprised two printed circuit boards (PCBs): a sensor PCB with a remote-gate electrode and an analyzer PCB with a metal-oxide-semiconductor field-effect transistor (MOSFET) transducer and peripheral electronics to manage sensor signals. To achieve a high sensitivity for Pb 2+ , we utilized graphene ink drop-casted on the sensor PCB as a sensing membrane. The graphene film was easy to deposit and remove, enabling the sensor PCB to be reused multiple times. The sensor system was further linked to a smartphone application that instantly monitors the sensor response, allowing for rapid point-of-use detection. The sensor exhibited a high sensitivity of 21.7% when the limit of detection (LOD) value of 1 nM (∼0.2 ppb) was detected, and the typical detection time for each sample was approximately 60 seconds. This portable sensor system advances sensing technologies and could potentially supplement expensive, laborious conventional sensing equipment.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Luminescent properties of solid solutions in the PbF{sub 2}–Euf{sub 3} system and lead fluoroborate glass ceramics doped with Eu{sup 3+} ions

Lead fluoroborate glasses doped with Eu{sup 3+} are synthesized, studied, and used to produce glassceramics by heat treatment. The structure of glass-ceramics is determined by X-ray diffraction. The optical, mechanical, and luminescent properties of the glass-ceramics are studied. The structure and spectral-luminescent properties of solid solutions in the PbF{sub 2}–EuF{sub 3} system obtained by both solid-phase reaction and coprecipitation from solutions are investigated.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2014

Preparation of a primary argon beam for the CERN fixed target physics

The fixed target experiment NA61 in the North Area of the Super Proton Synchrotron is studying phase transitions in strongly interacting matter. Up to now they used the primary beams available from the CERN accelerator complex (protons and lead ions) or fragmented beams created from the primary lead ion beam. To explore a wider range of energies and densities a request was made to provide primary argon and xenon beams. This paper describes the results of the setting up and 10 week test run of the Ar{sup 11+} beam from the 14.5 GHz ECR ion source and the linear accelerator (Linac3) at CERN.

43 PARTICLE ACCELERATORS↗
DOE OSTI2017

Fixed target project AFTER at the LHC beams for heavy ion and hadron physics

High intensity proton and lead ion beams at the LHC collider allow one to use the beam halo by placing a fixed target or a bent crystal for beam extraction. The particle energy in this case is just half that at the RHIC collider, but the luminosity exceeds the collider luminosity many times. It is also possible to install a polarized target in the extracted beam. The project AFTER is aimed at investigation of rare processes, polarization phenomena, determination of the parameters required for analysis of cosmic rays and neutrino astrophysics, detailed investigation of quarkonia production and suppression depending on the phase transition of matter to the quark-gluon phase.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

Development and testing of a pulsed helium ion source for probing materials and warm dense matter studies

The neutralized drift compression experiment was designed and commissioned as a pulsed, linear induction accelerator to drive thin targets to warm dense matter (WDM) states with peak temperatures of ∼1 eV using intense, short pulses (∼1 ns) of 1.2 MeV lithium ions. At that kinetic energy, heating a thin target foil near the Bragg peak energy using He{sup +} ions leads to more uniform energy deposition of the target material than Li{sup +} ions. Experiments show that a higher current density of helium ions can be delivered from a plasma source compared to Li{sup +} ions from a hot plate type ion source. He{sup +} beam pulses as high as 200 mA at the peak and 4 μs long were measured from a multi-aperture 7-cm-diameter emission area. Within ±5% variation, the uniform beam area is approximately 6 cm across. The accelerated and compressed pulsed ion beams can be used for materials studies and isochoric heating of target materials for high energy density physics experiments and WDM studies.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

Mechanisms of B Meson Suppression in Ultrarelativistic Heavy Ion Collisions

Different mechanisms of B meson suppression in lead ion collisions at an energy of the Large Hadron Collider √(s{sub NN}) = 5.02 TeV have been comparatively analyzed. It has been shown that the experimentally observed weak momentum dependence of the B meson suppression factor can be reproduced by the HYDJET++ model including the nuclear shadowing of initial parton distributions and radiative and collisional energy losses of heavy quarks in hot matter. A significant difference in the effects of the initial and final states on light and heavy hadron suppression has been revealed.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Role of Cations in the Cation-Driven Assembly Process and their Effect on the Charge Storage Properties of Bilayered Vanadium Oxide and Reduced Graphene Oxide Heterostructures in Alkali Ion Systems

Exfoliated δ-Li x V 2 O 5 ·nH 2 O (ex-LVO) and reduced graphene oxide (rGO) heterostructures were constructed using different assembling cations (i.e., Li⁺, Na⁺, and K⁺ ions). The ex-LVO and rGO nanoflakes were stacked together using a concentrated chloride solution of each assembling cation and vacuum annealed at 200 °C to form three distinct two-dimensional (2D) layered architectures. X-ray diffraction and thermogravimetric analysis confirmed that the assembling ions can control the interlayer spacing of the bilayered vanadium oxide (BVO) phase as well as impact the crystallographic water content, which in turn affects the electrochemical performance. Scanning electron microscopy, scanning transmission electron microscopy (STEM), electron energy-loss spectroscopy (EELS), and X-ray photoelectron spectroscopy confirmed that a 2D heterointerface formed between LVO and rGO and that the cations used to assemble the heterostructure are trapped in the interlayer BVO region. High-resolution STEM imaging also showed the rGO dispersion throughout the LVO layers. Moreover, STEM-EELS identified a V 2 O 3 phase that forms along the rGO interface and can stabilize the materials during cycling. A charge storage mechanism analysis, combined with the galvanostatic intermittent titration technique, found that increased interlayer spacings of the BVO phase and using the assembling cations to define intercalation sites for identical charge-carrying ions lead to improved ion diffusion and increased capacities during cycling. Therefore, the Li⁺ and Na⁺ ion assembled heterostructures showed improved charge-carrying ion diffusion and charge storage capacities in each of their respective charge storage systems (i.e., Li-ion and Na-ion half-cells). In total, the cation used for heterostructure assembly can modify the final material structure and tailor the ion diffusion and charge storage capacity to tune its properties for the desired electrochemical system using a variety of 2D materials.

25 ENERGY STORAGE↗
DOE OSTI2014

Magnetic and low temperature phonon studies of CoCr{sub 2}O{sub 4} powders doped with Fe(III) and Ni(II) ions

Extensive temperature-dependent phonon studies and low-temperature magnetic measurements of CoCr{sub 2−x}Fe{sub x}O{sub 4} (for x=0.5, 1 and 2) and Co{sub 0.9}Ni{sub 0.1}Cr{sub 2}O{sub 4} polycrystalline powders are presented. The main aim of these studies was to obtain information on phonon and structural properties of these compounds as well as strength of spin–phonon coupling in the magnetically ordered phases. IR and Raman spectra show that doping of CoCr{sub 2}O{sub 4} with Fe(III) ions leads to broadening of bands and appearance of new bands due to the formation of inverted spinel structure. In contrast to this behavior, doping with 10 mol% of Ni(II) ions leads to weak increase of band width only. Magnetization measured as a function of temperature and external magnetic field showed that magnetic properties of Co{sub 0.9}Ni{sub 0.1}Cr{sub 2}O{sub 4} sample are similar to those reported for pure CoCr{sub 2}O{sub 4}, i.e., partial substitution of Ni(II) for Co(II) leads to slight shift of the ferrimagnetic phase transition at T{sub C} and spiral spin order transition at T{sub S} towards lower values. The change of crystallization preference induced by incorporation of increasing concentration of Fe(III) ions in the spinel lattice causes significant increase of T{sub C} and decrease of T{sub S}. The latter transition disappears completely for higher concentrations of Fe(III). The performed temperature-dependent IR studies revealed interesting anomalous behavior of phonons below T{sub C} for CoCr{sub 1.5}Fe{sub 0.5}O{sub 4} and Co{sub 0.9}Ni{sub 0.1}Cr{sub 2}O{sub 4}, which was attributed to spin–phonon coupling. - Graphical abstract: Visualization of normal spinel-type AB{sub 2}O{sub 4} structure, where blue octahedrons denote BO{sub 6} and red tetrahedrons AO{sub 4} units as well as IR and Raman spectra of Co{sub 0.9}Ni{sub 0.1}Cr{sub 2}O{sub 4} powder. - Highlights: • T{sub C} (T{sub S}) increases (decreases) with increasing Fe(III) concentration. • Ni(II) ions doping up to 10 mol% does not change remarkably T{sub C} and T{sub S}. • Doping with Fe(III) ions causes increase of spinel inversion parameter. • Spin–phonon interactions in Co{sub 0.9}Ni{sub 0.1}Cr{sub 2}O{sub 4} and CoCr{sub 1.5}Fe{sub 0.5}O{sub 4} were evidenced.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Polarization of gold in nanopores leads to ion current rectification

Biomimetic nanopores with rectifying properties are relevant components of ionic switches, ionic circuits, and biological sensors. Rectification indicates that currents for voltages of one polarity are higher than currents for voltages of the opposite polarity. Ion current rectification requires the presence of surface charges on the pore walls, achieved either by the attachment of charged groups or in multielectrode systems by applying voltage to integrated gate electrodes. Here we present a simpler concept for introducing surface charges via polarization of a thin layer of Au present at one entrance of a silicon nitride nanopore. In an electric field applied by two electrodes placed in bulk solution on both sides of the membrane, the Au layer polarizes such that excess positive charge locally concentrates at one end and negative charge concentrates at the other end. Consequently, a junction is formed between zones with enhanced anion and cation concentrations in the solution adjacent to the Au layer. This bipolar double layer together with enhanced cation concentration in a negatively charged silicon nitride nanopore leads to voltage-controlled surface-charge patterns and ion current rectification. The experimental findings are supported by numerical modeling that confirm modulation of ionic concentrations by the Au layer and ion current rectification even in low-aspect ratio nanopores. Lastly, our findings enable a new strategy for creating ionic circuits with diodes and transistors.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Synthesis and Characterization of Magnetic Halloysite–Alginate Beads for the Removal of Lead(II) Ions from Aqueous Solutions

In this study, alginate (ALG) hybrid spheres supported with magnetic halloysite nanotubes (MHNTs) were synthesized and used effectively in the removal of Pb(II) ions from aqueous solutions. MHNTs were prepared using the “co-precipitation” method. Afterward, magnetic halloysite–alginate (MHNT–ALG) hybrid beads were formed using ALG and MHNTs by the “extrusion dripping” method. The characterization of halloysite nanotubes (HNTs), ALG, MHNTs, and MHNT–ALG hydrogels was performed using FTIR, TGA, particle size analysis, SEM–EDX, TEM, VSM, and BET. According to VSM measurements, the saturation magnetization values of MHNTs and MHNT–ALG hybrid beads at a mass ratio of 1:2 were determined to be 22.7 emu/g and 8.17 emu/g, respectively. The BET surface area of MHNT–ALG hybrid beads was measured to be 81.3 m{sup 2}/g. The adsorption of Pb(II) ions on MHNT–ALG hydrogels was investigated as a function of the pH of the medium, amount of MHNT–ALG, the mass ratio of MHNT to ALG in the composite, and initial Pb(II) concentration in batch stirred vessels. The fit of the adsorption equilibrium of Pb(II) ions on MHNT–ALG hydrogels to the Langmuir type-I and type-II models, Freundlich model, and Redlich–Peterson model was investigated. The fit of the adsorption kinetics to the pseudo-second-order kinetics model was evaluated. Using the Weber and Morris model, the effect of internal and external diffusion limitations was discussed.

36 MATERIALS SCIENCE↗