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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 901 records · Page 50
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Synthesis of perfluoroalkylene dianilines

The objective of this contrast was to optimize and scale-up the synthesis of 2,2-bis(4-aminophenyl)-hexafluoropropane and 1,3-bis(4-aminophenyl)hexafluoropropane, as well as to explore avenues to other perfluoroalkyl-bridged dianilines. Routes other than Friedel-Crafts reaction leading to 2,2-bis(4-aminophenyl)hexafluoropropane were investigated. The processes utilizing bisphenol-AF were all unsuccessful; reactions aimed at the production of 4-(hexafluoro-2-halo-isopropyl)aniline from the hydroxyl intermediate failed to yield the desired products. Tailoring the conditions of the Friedel-Crafts reaction of 4-(hexafluoro-2-hydroxyisopropyl)aniline, aniline, and aluminum chloride by using hydrochloride salts and selecting optimum reagent ratios, reaction times, and temperature resulted in approx. 20% yield of pure crystallized 2,2-bis(4-aminophenyl)hexafluoropropane in 0.2 mole reaction batches. Yields up to approx. 40% were realized in small, approx. 0.01 mole, batches. The synthesis of 1,3-bis(4-aminophenyl)hexafluoropropane starting with perfluoroglutarimidine was reinvestigated. The yield of the 4-step reaction sequence giving 1,3-bis(4-acetamidophenyl)hexafluoropropane was raised to 44%. The yield of the subsequent hydrolysis process was improved by a factor of approx. 2. Approaches to prepare other perfluoroalkyl-bridged dianilines were unsuccessful. Reactions reported to proceed readily with trifluoromethyl substituents failed when longer chain perfluoroalkyl groups were employed.

Paciorek, K. L.↗
NASA NTRS1990

Aircraft en route noise annoyance

Results are reported from a laboratory experiment conducted in order to quantify the annoyance experienced by people on the ground in response to en route noise (ERN) generated by aircraft at cruise conditions. Objectives included the comparison of annoyance responses to ERN with the annoyance responses to takeoff and landing noise; the comparison of the annoyance responses to advanced turboprop aircraft ERN with those of the turbofan ERN; and also the ability of aircraft noise measurement procedures and corrections to predict annoyance to ERN. Tests were conducted at the Langley Acoustics Research Laboratory on 32 human subjects selected at random. Subjects judged the annoyance level of 24 Propfan Test Assessment advanced turboprop ERN stimuli, 18 conventional turbofan ERN stimuli, and 60 conventional turboprop and turbofan takeoff and landing noise stimuli. Analysis of resulting data compared annoyance responses to different aircraft types and operations, examined the ability of current noise measurement and correction procedures to predict annoyance ERN, and calculated optimum duration correction magnitudes for ERN.

Mccurdy, David A.↗
DOE OSTI2025

Low temperature polyolefin deconstruction via tandem cracking-hydrogenation

The use of aluminum chloride in dichloromethane to crack polyolefin chains in tandem with alkylation of the resulting products has been previously reported as an efficient polyolefin recycling route. Building off this work, we report that a tandem cracking-hydrogenation system also efficiently converts polyolefins into gasoline-range light alkanes at mild temperatures without needing a hydrocarbon co-reactant. This Lewis acid and hydrogenation bifunctional system uses anhydrous aluminum chloride as the acid catalyst and Pd/C as a hydrogenation catalyst to achieve nearly 80 % conversion of low-density polyethylene (LDPE) at 70 °C in three hours, with 90+% selectivity towards gasoline-range (C 4 -C 12 ) branched alkanes. By combining the endothermic cracking reaction with the exothermic hydrogenation reaction, the thermodynamic limitations to low-temperature polyolefin deconstruction can be overcome. In using hydrogenation instead of alkylation, the system’s carbon efficiency is greatly improved, the cost of the reactants is reduced and the overall mass of both reactants and products reduced as well.

Alkylation↗
DOE OSTI2018

Growth of faceted SiC nanostructures using vapor phase condensation: Microstructural analysis

Highlights: • Synthesis of nanocrystalline SiC using thermal plasma route. • XRD data indicates presence of both α- and β-SiC polytypes with β-SiC as the major content. • HRTEM and SAED analysis reveals polytypic arrangement with stacking faults SiC nanoparticles. • TEM micrograph reveals presence of faceted structures such as hexagonal, triangular, triangular pyramidal structure. - Abstract: The paper emphasizes the morphological and microstructural analysis of SiC nanostructures grown by thermal plasma assisted gas phase condensation process. High Resolution Transmission Electron Microscopic and Selected Area Electron Diffraction studies are used to analyze the growth directions and the polytypic arrangement with stacking faults in the as synthesized SiC nanoparticles. The results help in understanding the hierarchical poly-types related to the observed geometries and showed the presence of both α- and β-SiC polytypes. The microstructural study is supported by X-Ray diffraction and UV–Visible absorption spectroscopic studies.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2018

Sodium Superionic Conductors Based on Clusters

Owing to the high abundance and low cost of sodium (Na), Na-based rechargeable batteries hold great potential for large-scale applications in the future energy industry. However, as key component of the battery electrolyte, only a few Na-based superionic conductors can reach the ionic conductivity comparable to that of liquid or gel electrolytes. Here, we provide a guideline for the development of cluster-based Na-rich antiperovskite superionic conductors using computational studies. With a selected cluster ion BCl 4 – , we are able to achieve high-room-temperature Na-ionic conductivity over 10 –3 S/cm and low activation energies below 0.2 eV in the antiperovskite crystals Na 3 S(BCl 4 ) and Na 3 S(BCl 4 ) 0.5 I 0.5 . In addition, these materials have large bandgaps and favorable mechanical properties. Here, a comprehensive study of the stability and formation energy of these materials further illustrates possible routes for their synthesis. New insights into the conduction mechanism of these cluster-based superionic conductors are provided, including the cooperative motion of Na ions and the significant reduction of the migration barrier due to the changing orientation of the cluster ion.

25 ENERGY STORAGE↗
DOE OSTI2015

DARWIN2 Low burnup validation for burnup credit using SFCOMPO PIE database - Verification of ICF values - 14433

The DARWIN package, developed by the CEA and its French partners (AREVA and EDF), provides the parameters required for fuel cycle applications, especially fuel inventory. It is widely used in the French Burnup Credit (BUC) calculation route, based on the connection of the depletion code DARWIN and the Criticality-Safety Package CRISTAL. The experimental validation process of BUC nuclides provided by DARWIN2.3 package consists in the comparison between JEFF-3.1.1-based calculated values of isotopic concentrations and experimental values obtained from the chemical analysis of PWR fuel rod cuts. As a complement to the extensive validation using the French PIE database, specific PIE data chosen for their quality were selected and analyzed in the SFCOMPO database of NEA. A set of 56 samples chosen in PWR-UO{sub 2} experiments was selected, with initial {sup 235}U enrichment between 2.7% and 4.1% and local burnup estimated from {sup 148}Nd measurement varying between 7 and 35 GWd/tHM. This paper provides an overview of calculation - experiment comparison obtained in Takahama-3 17x17, Trino-Vercellese 15x15 and Obrigheim 14x1 for uranium, plutonium isotopes, as well as available fission products contributing to the assembly reactivity. Consistent biases compared to SCALE5 results were obtained. From these results, an analysis is driven using 15 selected samples with low burnup, selected among asymptotic rods of irradiated fuels at 1 or 2 cycles. This paper shows the consistency of the calculation - experiment biases obtained with DARWIN2.3 towards previously defined penalized biases used for the Isotopic Correction Factors (ICF) in BUC applications. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2025

Facet-Dependent Hydrogen Evolution Reaction on M 2 P (M = Ni, Co, Fe) Single Crystals

Transition-metal phosphides (MPs) are promising earth-abundant catalysts for hydrogen evolution reactions (HERs) due to their remarkable activity and stability. To further improve their properties, facet control is a key strategy. The growth of shape-selected nanoparticles may substantially enhance electrocatalytic activity, but this approach requires fundamental studies of facet-specific catalytic properties. There are only a few reports on the facet effects of MPs, which leads to a limited understanding of the activity of each facet and hampers catalyst design. Here, in this study, we grew large hexagonal-prism-shaped single crystals of three representative M 2 P (M = Ni, Co, and Fe) catalysts using metal flux routes. Two facets of M 2 P single crystals were tested to study facet-dependent HER activities, and it was consistently demonstrated that for all M 2 P crystals, a tip facet [(0001) for Ni 2 P/Fe 2 P and (010) for Co 2 P] had a higher activity than the side facet [(101̅0) for Ni 2 P/Fe 2 P and (100) for Co 2 P]. HER activity between the same facet elucidated the activity ordered between different transition metals as Fe 2 P > Co 2 P > Ni 2 P under low-potential regions. At high applied potentials, this trend is reversed due to the differences in Tafel slopes, with Ni 2 P becoming the most active catalyst, such that the activity of the (0001) facet of Ni 2 P approaches that of Pt. The calculated surface density of states (DOS) of each facet and its local curvature were found to be a useful descriptor for the activity trends among different transition metals of the same facets.

Co2P↗
DOE OSTI2021

Recyclable Graphene Sheets as a Growth Template for Crystalline ZnO Nanowires

Recent advances in nanoscience have opened ways of recycling substrates for nanomaterial growth. Novel materials, such as atomically thin materials, are highly desirable for the recycling substrates. In this work, we report recycling of monolayer graphene as a growth template for synthesis of single crystalline ZnO nanowires. Selective nucleation of ZnO nanowires on graphene was elucidated by scanning electron microscopy and density functional theory calculation. Growth and subsequent separation of ZnO nanowires was repeated up to seven times on the same monolayer graphene film. Raman analyses were also performed to investigate the quality of graphene structure along the recycling processes. The chemical robustness of graphene enables the repetitive ZnO nanowire growth without noticeable degradation of the graphene quality. This work presents a route for graphene as a multifunctional growth template for diverse nanomaterials such as nanocrystals, aligned nanowires, other two-dimensional materials, and semiconductor thin films.

36 MATERIALS SCIENCE↗
NASA NTRS1974

Preliminary road alinement through the Great Kavir in Iran by repetitive ERTS-1 coverage

Access to the Great Kavir is generally limited to the period August through October when some salt crusts will support limited vehicular movement. The condition of the salt crusts and their parent sediments during the long wet season have been unknown. This absence of information about the surface of the Great Kavir has prevented an intensive study of a possible road alinement which could shorten the present route between northern and central Iran by 760 km. False color diazo composites of bands 4, 5, and 7 were prepared from positives of ERTS-1 MSS images taken of the Great Kavir. These scenes presented a record of the seasonal hydrologic changes that occurred from the dry to the wet season. During the period of maximum inundation and lowest bearing strengths, as inferred from the image of May 12, 1973, it was possible to select a preliminary road alinement that would avoid the wettest or roughest areas and take advantage of the best terrain and shortest distance. The eventual road alinement should be based on a longer record of observation and on-site investigations.

Krinsley, D. B.↗
DOE OSTI2025

Pressure-Induced Stacking of Rhodamine 6G Molecules

Extended conjugation of molecular π systems are of great significance for solar cells and organic light-emitting diodes as these can serve as new light absorbing and emitting chromophores. This research demonstrates the potential of using pressure and solvent environment to create larger assemblies of molecular π-conjugated systems. Here, we selected rhodamine 6G (Rh6G) to study the pressure-induced stacking of molecules in three different solvents: methanol (MeOH), isopropanol (IPA), and 16:3:1 mixture of methanol: ethanol: water (MEW). Absorption, emission, and fluorescence lifetime were studied at pressures up to 11.38 GPa. We found that pressure-induced stacking mechanisms can present solvent dependence: high pressures tend to create emissive Haggregates in MeOH and MEW, but excimers in IPA. This work guides and demonstrates routes to stacking of organic molecules using high pressures and provides fundamental insights into the formation of extended conjugation π systems.

Johnson, Kade [Univ. of Texas at San Antonio, TX (↗
DOE OSTI2016

Competition between deformability and charge transport in semiconducting polymers for flexible and stretchable electronics

The primary goal of the field concerned with organic semiconductors is to produce devices with performance approaching that of silicon electronics, but with the deformability—flexibility and stretchability—of conventional plastics. However, an inherent competition between deformability and charge transport has long been observed in these materials, and achieving the extreme (or even moderate) deformability implied by the word “plastic” concurrently with high charge transport may be elusive. This competition arises because the properties needed for high carrier mobilities—e.g., rigid chains in π-conjugated polymers and high degrees of crystallinity in the solid state—are antithetical to deformability. On the device scale, this competition can lead to low-performance yet mechanically robust devices, or high-performance devices that fail catastrophically (e.g., cracking, cohesive failure, and delamination) under strain. There are, however, some observations that contradict the notion of the mutual exclusivity of electronic and mechanical performances. These observations suggest that this problem may not be a fundamental trade-off, but rather an inconvenience that may be negotiated by a logical selection of materials and processing conditions. For example, the selection of the poly(3-alkylthiophene) with a critical side-chain length—poly(3-heptylthiophene) (n = 7)—marries the high deformability of poly(3-octylthiophene) (n = 8) with the high electronic performance (as manifested in photovoltaic efficiency) of poly(3-hexylthiophene) (n = 6). This review explores the relationship between deformability and charge transport in organic semiconductors. The principal conclusions are that reducing the competition between these two parameters is in fact possible, with two demonstrated routes being: (1) incorporation of softer, insulating material into a stiffer, semiconducting material and (2) increasing disorder in a highly ordered film, but not enough to disrupt charge transport pathways. The aim of this review is to provide a bridge between the fields interested in electronic properties and mechanical properties of conjugated polymers. We provide a high-level introduction to some of the important electronic and mechanical properties and measurement techniques for organic electronic devices, demonstrate an apparent competition between good electronic performance and mechanical deformability, and highlight potential strategies for overcoming this undesirable competition. A marriage of these two fields would allow for rational design of materials for applications requiring large-area, low-cost, printable devices that are ultra-flexible or stretchable, such as organic photovoltaic devices and wearable, conformable, or implantable sensors.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2018

Mechanically active materials in three-dimensional mesostructures

Complex, three-dimensional (3D) mesostructures that incorporate advanced, mechanically active materials are of broad, growing interest for their potential use in many emerging systems. The technology implications range from precision-sensing microelectromechanical systems, to tissue scaffolds that exploit the principles of mechanobiology, to mechanical energy harvesters that support broad bandwidth operation. The work presented here introduces strategies in guided assembly and heterogeneous materials integration as routes to complex, 3D microscale mechanical frameworks that incorporate multiple, independently addressable piezoelectric thin-film actuators for vibratory excitation and precise control. The approach combines transfer printing as a scheme for materials integration with structural buckling as a means for 2D-to-3D geometric transformation, for designs that range from simple, symmetric layouts to complex, hierarchical configurations, on planar or curvilinear surfaces. Systematic experimental and computational studies reveal the underlying characteristics and capabilities, including selective excitation of targeted vibrational modes for simultaneous measurements of viscosity and density of surrounding fluids. The results serve as the foundations for unusual classes of mechanically active 3D mesostructures with unique functions relevant to biosensing, mechanobiology, energy harvesting, and others.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Supramolecular Control of Redox-Mediated Interactions for Ion-Selective Electroseparations

This report summarizes efforts from the Su Group at the University of Illinois at Urbana-Champaign in researching and developing materials and processes for the recovery of rare earth elements and other metal elements that are critical to the United States economy and national security, under DOE Award No. DE-SC0021409. This report highlights efforts in the recovery of: • Transition metal elements (including arsenic, chromium, molybdenum, rhenium, vanadium): Redox-active metallopolymers are able to capture these elements in their oxyanion form. Direct control of target ion capture/release through electrochemical-mediated switching of metallocene binding sites reduces chemical input and lowers generation of waste in element recovery processes. We study the effects of metallopolymer structure on targeted ion binding through a combination of experimental screening of ion selectivity from multi-component mixtures, computational efforts which elucidate the charge-transfer origins of metallocene binding and provide insight on how binding site structure influences selectivity, and state-of-the-art neutron reflectivity of metallocene polymer films to understand the interplay of polymer-ion (charge-transfer), polymer-solvent (polymer hydrophilicity/hydrophobicity), and ion-solvent (ion hydration) interactions with spatial resolution of polymer films. • Rare earth elements (including yttrium, neodymium, europium, gadolinium, dysprosium, cerium): Here we employ redox-copolymers for recovery of rare earth elements by electrochemically regenerated ion-exchange. Rare earth elements require an alternative route to capture/release than directly with metallopolymers since rare earth elements typically exist in cationic form in water. To address this, copolymerization of traditional ion-exchange moieties with metallocene moieties allowed for capture of rare earth elements with the ion-exchange moieties and electrochemical-mediated release of rare earth elements through oxidation of metallocene moieties.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Growth of vertically aligned α−MoO{sub 3} nanoflakes by using a facile PVD route

In this report, we synthesize vertically aligned molybdenum trioxide (α−MoO{sub 3}) nanoflakes (NFs) with high aspect ratio (height/thickness >15) on the cobalt coated glass substrates by the plasma assisted sublimation process, employing Mo metal strip as a sublimation source. The effect of substrate temperature, nature of substrate as well as the geometry of the sublimation source (Mo-strip) have been investigated on the morphological, structural and optical properties of the grown NFs, keeping plasma parameters as fixed. The surface morphology, crystalline structure and optical properties of MoO{sub 3} NFs have been studied systematically by using scanning electron microscope (SEM), transmission electron microscope (TEM) with selected area electron diffraction (SAED), X-ray diffractometer, and IR- spectroscopy. The experimental observations endorse that the characteristics of MoO{sub 3} NFs are strongly depend on substrate temperature, substrate nature as well as geometry of Mo-strip. All the observed results are well in consonance with each other.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2025

NiAl–MoO 2 S 2 Nanoparticles: Structural Evolution and Mechanistic Insights into High-Performance Selenium Oxyanion Removal across Diverse pH Conditions

Advancing sorbent materials for the selective removal of toxic oxyanions from water requires synthetic control, tunable chemistry, and an atomic-level understanding of structure–function relationships. Here, we report the synthesis and detailed characterization of NiAl–MoO 2 S 2 , a novel layered double hydroxide (LDH) nanomaterial designed for the efficient sequestration of selenium oxoanions (SeO 3 2– and SeO 4 2– ) from complex aqueous environments. The material is synthesized through a room-temperature ion-exchange process, wherein interlayer NO 3 – anions in NiAl–LDH are replaced with MoO 2 S 2 2– clusters, forming high-surface-area, flower-like nanoparticles. Comprehensive structural analysis using the synchrotron X-ray pair distribution function, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy reveals a distinct chemical transformation of intercalated [MoO 2 S 2 ] 2– into [Mo 2 O 2 S 6 ] 2– -like clusters, generating redox-active interlayers that drive selenium capture. This tailored interfacial chemistry underpins the material’s exceptional sorption performance, achieving distribution coefficients (K d ) ≥ 10 6 mL/g and maximum capacities of 343 mg/g for SeO 4 2– and 514 mg/g for SeO 3 2– , outperforming state-of-the-art inorganic sorbents. Importantly, NiAl–MoO 2 S 2 maintains high selectivity and capacity across acidic, neutral, and alkaline pH, efficiently removing selenium from ppm to sub-10 ppb trace levels, even in the presence of competing ions typical of natural and industrial waters. The selenium uptake proceeds via reductive precipitation coupled with the oxidation of molybdenum and sulfide within the LDH framework. This study highlights the power of strategic synthetic modification and interlayer functionalization in LDHs to unlock new structural motifs and redox chemistries, offering a scalable route to advanced materials for environmental remediation.

Adsorption↗
DOE OSTI2022

Orthogonal glycolytic pathway enables directed evolution of noncanonical cofactor oxidase

Abstract Noncanonical cofactor biomimetics (NCBs) such as nicotinamide mononucleotide (NMN + ) provide enhanced scalability for biomanufacturing. However, engineering enzymes to accept NCBs is difficult. Here, we establish a growth selection platform to evolve enzymes to utilize NMN + -based reducing power. This is based on an orthogonal, NMN + -dependent glycolytic pathway in Escherichia coli which can be coupled to any reciprocal enzyme to recycle the ensuing reduced NMN + . With a throughput of >10 6 variants per iteration, the growth selection discovers a Lactobacillus pentosus NADH oxidase variant with ~10-fold increase in NMNH catalytic efficiency and enhanced activity for other NCBs. Molecular modeling and experimental validation suggest that instead of directly contacting NCBs, the mutations optimize the enzyme’s global conformational dynamics to resemble the WT with the native cofactor bound. Restoring the enzyme’s access to catalytically competent conformation states via deep navigation of protein sequence space with high-throughput evolution provides a universal route to engineer NCB-dependent enzymes.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2026

Microwave-Assisted Methane Dehydroaromatization: Impact of Process Parameters

Flaring of associated natural gas is a significant challenge for oil and gas producers that often results in high amounts of lost revenue for the industry. One way to improve economics of this process is to convert natural gas into value-added chemicals using chemical conversion. Methane, which is the principal component of natural gas, can typically be converted into valuable aromatics using non-oxidative conversion routes such as dehydroaromatization. For the current work, methane dehydroaromatization was investigated in a microwave-assisted reactor and the effect of various parameters such as reaction temperature (550-750 °C) and space velocity (3-8 L/gcat/hr) were studied. Both the parameters had a very strong effect on the overall performance of the reaction. The variation in temperature had significant impact on the overall methane conversion, whereas the variation in space velocity had significant impact on the selectivity and product distribution.

methane dehydroaromatization↗
DOE OSTI2022

Liquid Copper and Iron Production from Chalcopyrite, in the Absence of Oxygen

Clean energy infrastructure depends on chalcopyrite: the mineral that contains 70% of the world’s copper reserves, as well as a range of precious and critical metals. Smelting is the only commercially viable route to process chalcopyrite, where the oxygen-rich environment dictates the distribution of impurities and numerous upstream and downstream unit operations to manage noxious gases and by-products. However, unique opportunities to address urgent challenges faced by the copper industry arise by excluding oxygen and processing chalcopyrite in the native sulfide regime. Through electrochemical experiments and thermodynamic analysis, gaseous sulfur and electrochemical reduction in a molten sulfide electrolyte are shown to be effective levers to selectively extract the elements in chalcopyrite for the first time. We present a new process flow to supply the increasing demand for copper and byproduct metals using electricity and an inert anode, while decoupling metal production from fugitive gas emissions and oxidized by-products.

36 MATERIALS SCIENCE↗