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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 775 records · Page 43
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Nanoparticle surfactants and structured liquids

Materials are usually classified as solids or liquids, based on their structural stability, dynamic response, and rheological properties. Structured liquid, a new state of matter, has attracted much attention in recent years. Different with either solid or liquid, structured liquid combines the desirable characteristics of fluids with the structural stability of a solid, showing a myriad of potential applications in encapsulation, biphasic reactors, and programmable liquid constructs. Here, a brief review is given, by introducing a new strategy to structure liquids based on the formation, assembly, and jamming of nanoparticle surfactants (NPSs) at liquid-liquid interfaces. Furthermore, the interfacial packing of the NPSs can be effectively manipulated using external triggers, endowing the structured liquids with adaptiveness and responsiveness to changes in their external environment.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Fully Integrated Ultra-thin Intraoperative Micro-imager for Cancer Detection Using Upconverting Nanoparticles

Abstract Purpose Intraoperative detection and removal of microscopic residual disease (MRD) remain critical to the outcome of cancer surgeries. Today’s minimally invasive surgical procedures require miniaturization and surgical integration of highly sensitive imagers to seamlessly integrate into the modern clinical workflow. However, current intraoperative imagers remain cumbersome and still heavily dependent on large lenses and rigid filters, precluding further miniaturization and integration into surgical tools. Procedures We have successfully engineered a chip-scale intraoperative micro-imager array—without optical filters or lenses—integrated with lanthanide-based alloyed upconverting nanoparticles (aUCNPs) to achieve tissue imaging using a single micro-chip. This imaging platform is able to leverage the unique optical properties of aUCNPs (long luminescent lifetime, high-efficiency upconversion, no photobleaching) by utilizing a time-resolved imaging method to acquire images using a 36-by-80-pixel, 2.3 mm $$\times$$ × 4.8 mm silicon-based electronic imager micro-chip, that is, less than 100-µm thin. Each pixel incorporates a novel architecture enabling automated background measurement and cancellation. We have validated the performance, spatial resolution, and the background cancellation scheme of the imaging platform, using resolution test targets and mouse prostate tumor sample intratumorally injected with aUCNPs. To demonstrate the ability to image MRD, or tumor margins, we evaluated the imaging platform in visualizing a single-cell thin section of the injected prostate tumor sample. Results Tested on USAF resolution targets, the imager is able to achieve a resolution of 71 µm. We have also demonstrated successful background cancellation, achieving a signal-to-background ratio of 8 when performing ex vivo imaging on aUCNP-injected prostate tumor sample, improved from originally 0.4. The performance of the imaging platform on single-cell layer sections was also evaluated and the sensor achieved a signal-to-background ratio of 4.3 in resolving cell clusters with sizes as low as 200 cells. Conclusion The imaging system proposed here is a scalable chip-scale ultra-thin alternative for bulky conventional intraoperative imagers. Its novel pixel architecture and background correction scheme enable visualization of microscopic-scale residual disease while remaining completely free of lenses and filters, achieving an ultra-miniaturized form factor—critical for intraoperative settings.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Paper-based gold nanoparticles decorated SWCNTs chemiresistive sensor for sensitive detection of As(III) based on electrochemical doping

A paper-based chemiresistive sensor consisting of a single-walled carbon nanotubes network with electrodeposited gold nanoparticles (AuNPs-SWCNTs) was developed for the sensitive detection of As(III). A new sensing strategy was also proposed combined with a paper-based device for As(III) chemiresistive detection based on the electrochemical doping of As(0) on the AuNPs-SWCNTs channel. Here, the proposed paper-based chemiresistive sensor was manufactured by wax printing and vacuum deposition using a water-based SWCNTs ink. The sensor sensitivity was enhanced by optimizing the volume of SWCNTs ink used in the formation of the sensing network in the paper and the sweep segment of cyclic voltammetry used for the electrochemical deposition of AuNPs. Additionally, the mechanism of the sensing strategy based on the electrochemical n-doping of As(0) to the AuNPs-SWCNTs sensing channel was investigated using a liquid-ion gated FET system. The As(III) concentration detected by the as-fabricated chemiresistive sensor is as low as 1.35 × 10 -5 μM which is even lower than the maximum permissible concentration in drinking water defined by the WHO. In this paper, we provide a simple strategy for developing paper-based chemiresistive sensors with unique properties for practical As(III) determination.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Morphing Mn core @Pt shell nanoparticles: Effects of core structure on the ORR performance of Pt shell

Currently, the catalysts performance for the oxygen reduction reaction (ORR) is limited by two major factors, their price and the scaling relationship, i.e. constant offset, between the binding energy of reactants and reaction intermediates. Here we show that both limitations may be eased by using nanoparticle catalysts composed of a core of earth-abundant Mn and Pt shell of two atomic layers. We report the unusual atomic-structure of Mn core renders the distribution of coordination numbers and related atomic-level stresses on the Pt shell very broad in com- parison to pure Pt particles. This increases the chances of nearby sites on the shell to affect each other’s activity such that the dissociative absorption of molecular oxygen is facilitated without correspondingly increasing the binding strength of reaction intermediates, thereby promoting the ORR kinetics. Our findings introduce the concept of structural flexibility of the 3d-metal core and 5d-Pt shell as a strategy for catalysis performance.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Single-phase Ru 1- x-y Mn x Co y O 2 nanoparticles as highly effective oxygen reduction electrocatalysts in alkaline media with enhanced stability and fuel-tolerance

Here, a series of single-phase binary and ternary ruthenium and transition metal oxide nanoparticles supported on Vulcan - Ru 1-x MnxO2/C, Ru1-xCoxO 2 /C, Ru 1-x-y MnxCo y O 2 /C, Ru 1-x Fe x O 2 /C, Ru 1-x Ni x O 2 /C and Ru 1-x V x O 2 /C, as well as RuO 2 /C, MnO 2 /C, Co 3 O 4 /C and Mn 3-x Co x O 4 /C - were synthesized via a facile method and studied for their oxygen reduction reaction (ORR) activity in alkaline media. Single-phase Ru 1-x Mn x O 2 /C, Ru 1-x-y Mn x Co y O 2 /C and Ru 1-x Co x O 2 /C catalysts significantly boosted ORR kinetics in alkaline media. Moreover, they were H 2 and methanol tolerant, and exhibited long term stability due to their single-phase structure. Ru 0.85 Mn 0.15 O 2 /C stood out as the most active catalyst among them. A volcano relationship of the ORR activity of these binary and ternary metal oxide catalysts vs. the O adsorption energy was found, with the maximum activity observed for the Ru 1-x Mn x O 2 /C, Ru 1-x-y Mn x Co y O 2 /C and Ru 1-x Co x O 2 /C catalysts due to their optimal O binding energy. These materials have potential applications as highly active ORR catalysts in alkaline fuel cells and metal-air batteries.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Effect of Cu nanoparticles on the tribological performance of polydopamine + polytetrafluoroethylene coatings in oil-lubricated condition

For this study, the effect of Cu nanoparticles (NPs) on the tribological performance of the thick polydopamine (PDA) + polytetrafluoroethylene (PTFE) coatings in DTE-32 Mobil lubricated condition was investigated. PDA + PTFE + Cu NP coatings with 45 µm thickness were spray-coated with 0.12, 0.25, and 0.50 wt% of Cu NPs in an aqueous PDA + PTFE solution, respectively. The mechanical properties were studied by PeakForce quantitative nanomechanical (PFQNM) characterization and nanoindentation. The Young's modulus increased, and the coefficient of friction (COF) reduced with the addition of Cu NPs compared to PDA + PTFE coating. The PDA + PTFE + 0.25 wt% Cu and PDA + PTFE + 0.50 wt% Cu coatings increased the durability by 52% and 33%, respectively, compared to the coating without Cu NPs. The better tribological performance of the nanocomposite coatings is contributed by the better mechanical properties, better adherence, and enhanced cross-linking between the constituents of the nanocomposite coatings due to the presence of Cu NPs. The addition of 0.25 wt% Cu NPs in PDA + PTFE increased the thermal conductivity by 12%.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Towards synthetic L 1 0 -FeNi: Detecting the absence of cubic symmetry in Laser-Ablated Fe-Ni nanoparticles

The L 1 0 crystal structure underlines an important class of chemically ordered alloys that exhibits uniaxial magnetocrystalline anisotropy. The near-equiatomic L 1 0 -FeNi extracted from meteorites has demonstrated intriguing magnetic properties for permanent magnet applications. However, the synthesis of this chemically ordered non-cubic structure has been a longstanding challenge. Here, in this work, we demonstrate the absence of cubic symmetry in near-equiatomic Fe-Ni nanoparticles synthesized by picosecond-pulsed laser ablation in liquids. The non-cubic phase detected in these particles can only be L 1 0 -FeNi or hexagonal close-packed (HCP) FeNi, and the absence of cubic symmetry was unequivocal. The orientation relationship between the non-cubic phase and the adjacent cubic phase was characterized by a series of transmission electron microscopy (TEM) techniques, which consistently suggests that the formation of the non-cubic phase involves a martensitic transformation process.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Investigation on the AgPt and AgPd hybrid alloy nanoparticles (HANPs) for the hybrid MoS 2 /ZnO/HANP UV photodetector application

We report hybrid photodetectors made of two or more nanomaterial components can offer the high potential for advanced photodetection applications with enhanced light absorption, improved efficiency and structural tunability. A hybrid UV photodetector (PD) configuration incorporating the plasmonic hybrid alloy nanoparticles (HANP), ZnO quantum dots (QDs) and MoS 2 nanoflakes, namely MoS2/ZnO/HANP PD, is demonstrated. The optimized MoS 2 /ZnO/HANP PD exhibits a high photocurrent of 5.66 mA at 0.34 mW/mm 2 under 385 nm illumination with two orders of improvement from the bare ZnO, which is one of the highest photocurrents by the ZnO-based PDs. It also demonstrates high figure-of-merits with the responsivity of 14,523 mA/W, detectivity of 8.13 x 10 11 jones, and external quantum efficiency (EQE) of 4,680 %, outperforming most of the ZnO-based hybrid architectures. The enhanced photoresponse is primarily attributed to the significantly enhanced hot electron generation by the AgPd HANPs and photocarrier collection through the ZnO QD layer. MoS 2 nanoflakes also provide additional photon absorption sites and boost the photo-carrier transfer process. HANPs are grown by adapting a dual-step solid-state dewetting process (SSD) approach and the superiority of AgPd HANPs is confirmed by systematic investigation, FDTD simulation and comparison of AgPt and AgPd HANPs.

MoS2↗
DOE OSTI2019

Cancer cell membrane-coated rare earth doped nanoparticles for tumor surgery navigation in NIR-II imaging window

With the attractive characteristics of low toxicity, narrow emission spectra, long fluorescence lifetime, and no photobleaching, rare-earth doped nanoparticles (RENPs) have become promising imaging nanoplatforms in the second near-infrared window (NIR-II, 1000–1700 nm). Many studies have been devoted to different surface modification strategies of RENPs to achieve good NIR-II tumor imaging property. However, the tumor imaging efficiency of these approaches remains disappointing. Herein, two methods were pursued to modify RENPs with either polyethylene glycol (PEG) or cancer-cell-membrane to generate PEGylated-RENPs and cancer-cell-membrane camouflaged RENPs (CC-RENPs), respectively. Furthermore, this study demonstrated that cancer-cell-membrane coating of RENPs greatly improved tumor imaging performance in NIR-II window than PEG coating. Besides, CC-RENPs uptakes in liver and spleen significantly decreased. Importantly, CC-RENPs was found to be capable to aid us to pursue precise resection of the tumor. In conclusion, CC-RENPs are capable of targeting tumors and show high tumor NIR-II imaging quality. They are highly promising nanomaterials for future medical applications.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2021

Rheology of fresh cement pastes containing polymer nanoparticles

Influences of polymer nanoparticles (PNPs) with varied charge densities on the rheological behaviors of fresh cement pastes (fcps) without and with polycarboxylate superplasticizer (PCE) were studied. In the blank fcp, the addition of PCE and highly anionically charged PNPs greatly decreases the yield stress and the plastic viscosity due to their large adsorption on cement that produces electrostatic repulsion and steric hindrance between cement grains. However, the non-adsorbing nonionic PNPs show a slightly opposite effect. In the PCE-containing fcp, both the anionic and nonionic PNPs become non-adsorbing on cement due to the stronger affinity of PCE to cement surface. In this way, the addition of the PNPs in the PCE-containing fcp slightly increases the yield stress and the plastic viscosity, but significantly decreases the pseudoplastic index, which is believed to result from the generation of the so-called depletion attractive force between cement grains induced by the non-adsorbing polymers.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Nanoparticles caged with DNA nanostructures

Nanoparticles (NPs) offer many benefits in biotechnology because of their small size and unique properties. Furthermore, many applications require precise positioning of the NPs or biological targeting molecules on their surfaces. DNA cages constructed from DNA tile, origami, or wireframe nanostructures offer a promising path forward because of their simplicity and programmability that can be used to generate complex, dynamic 2D and 3D geometries. Such materials can be used to pattern DNA on NP surfaces and organize NPs into specific supramolecular structures. DNA-caged NPs can be implemented in biosensing and drug delivery applications with cavities precisely designed to encapsulate-specific biomolecules. Ultimately, such approaches provide a springboard for future DNA robot designs that will enable controlled interactions with biological systems.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

Carbon dots from surface-capping/passivation of small carbon nanoparticles with nanoscale titanium dioxide

Carbon dots are classically defined as small carbon nanoparticles (CNPs) with effective surface passivation, which has been accomplished predominantly by surface organic functionalization. In the current work, the passivation is achieved by the surface coating of CNPs with nanoscale TiO 2 for CNP/TiO 2 core/shell nanostructures, which are analogous to conventional semiconductor core/shell quantum dots (QDs). The TiO 2 capping of CNPs results in substantial enhancements in the fluorescence quantum yields, also analogous to the similar enhancements famously known for the semiconductor QDs. In conclusion, mechanistic implications of the findings, including the associated further validation on the classical definition of carbon dots, are discussed.

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

Effect of crystallite size on lithium storage performance of high entropy oxide (Cr 0.2 Mn 0.2 Co 0.2 Ni 0.2 Zn 0.2 ) 3 O 4 nanoparticles

High-entropy oxides (HEOs), known for their high theoretical capacity and structural stability, are considered promising anode materials for next-generation lithium-ion batteries (LIBs). In this research, we synthesized a novel spinel-type HEO, (Cr 0.2 Mn 0.2 Co 0.2 Ni 0.2 Zn 0.2 ) 3 O 4 , using a solution combustion method. By adjusting the quantity of the combustion agent, we produced samples with varying crystallite sizes. The crystallite size of the HEOs initially enlarges with an increased combustion agent, then diminishes. The enhancement of crystallite size correlates with improved electrochemical performance for lithium storage. Notably, the (Cr 0.2 Mn 0.2 Co 0.2 Ni 0.2 Zn 0.2 ) 3 O 4 nanoparticles, with the largest crystallite size of 36.3 nm, demonstrated a reversible capacity of 343 mA h g -1 after 100 cycles at 100 mA g -1 , a capacity retention to 319 mA h g -1 after 1000 cycles at 1 A g -1 , and a commendable rate capability of 260 mA h g -1 at 2 A g -1 . Furthermore, this study underscores the pivotal role of crystallite size in LIB performance and presents a viable strategy to enhance the lithium storage capabilities of HEOs and other metal oxides.

25 ENERGY STORAGE↗
DOE OSTI2021

Synergistic foam stabilization and transport improvement in simulated fractures with polyelectrolyte complex nanoparticles: Microscale observation using laser etched glass micromodels

Inaccessibility to direct pore scale observation in hydrocarbon recovery of tight shale formations poses a great challenge to water-energy nexus initiatives and necessitates the use of high throughput technologies to emulate environmentally friendly processes. Herein, we employ a precise glass micromodel fabrication and visualization method to isolate the supercritical CO 2 bubbles surrounded by CO 2 -water lamella prepared in saline produced water stabilized with molecular complexation of zwitterionic surfactants (ZS) and polyelectrolyte complex nanoparticles (PECNP). The Selective Laser Enhanced Etching (SLE) technique was selected for micromodel simulation of high-pressure flow. Two representative designs, (1) fracture/micro-crack network 28 and (2) fracture/matrix were etched on fused silica glass with a laser printing machine and scCO 2 foam was injected to study the foamability, propagation, stability, and fluid loss properties. The highly monodispersed and uniformly distributed array of scCO 2 bubbles were detected in flow of scCO 2 foam in highly saline brine containing ionic complexes of positively charged PECNPs and ZS, whereas foam flow with the lamella containing ZS in fractures offered a noticeably large and polydisperse array of scCO 2 bubbles. scCO 2 bubble motion and deformation were traced, and local description of foam flow was visually examined. The confined array of scCO 2 bubbles stabilized by ZS in microcracks was affected by bubble growth and coalescence, whereas the super-populated array of monodispersed scC O2 bubbles with lamella containing complexes of PECNP and ZS were able to fill the channels with stable configurations within the timeframe of comparative stability measurements. The ability of complex fluid to prevent the formation damage was evaluated through fluid loss visualization in micromodels. Probing scCO 2 foam transport in homogenous porous media revealed smaller volume leak-off for scCO 2 foam containing PECNP-ZS ionic complexes.

04 OIL SHALES AND TAR SANDS↗
DOE OSTI2021

Facet-specific oxidation of Mn(II) and heterogeneous growth of manganese (oxyhydr)oxides on hematite nanoparticles

It is recognized that different facets of minerals vary distinctively in their chemical reactivity with aqueous solutions. However, detailed molecular and atomistic understandings of these phenomena are relatively limited. This study investigated the interaction of aqueous Mn2+ and dissolved oxygen on various facets of two morphology-types of iron oxide (hematite) nanocrystals. These interactions result in the oxidation of manganese and the heterogeneous nucleation and growth of Mn(II)/Mn(III), and Mn(III) oxides. The nanoscale morphology and atomic structure of the manganese oxide products were characterized in detail. Our results, for the first time, directly demonstrate the facet-dependent oxidation of Mn 2+ and nucleation of Mn(II/III) oxides, followed by their epitaxial growth on hematite. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electron diffraction measurements reveal the growth of MnOx nanowires on {012} facets of both hematite nanoplates (HNP) and hematite nanocubes (HNC), while the basal {001} facets on the HNP particles do not produce precipitates. The average oxidation state of the MnO x on HNP and HNC determined using electron energy-loss spectroscopy (EELS) show that both Mn(II) and Mn(III) are present. The facet-dependent oxidation of Mn 2+ may be attributed to adsorption-induced electron transfer (ET), and hematite {001} facets generally exhibiting weaker ability in the uptake of ions relative to {012} facets, and the bulk ET from {012} to {001} facets through the conduction band of hematite. Nevertheless, the mineral composition and growth mechanisms of MnOx catalyzed by HNP and HNC are similar. High-resolution TEM analysis reveals the presence of both hausmannite and manganite on HNP and HNC. The nanoscale observations and thermodynamic considerations indicate that the growth mechanisms/processes of MnO x include heterogeneous nucleation of hausmannite nanoparticles, crystallization by particle attachment, transformation from hausmannite to manganite, and self-catalyzed MnO x growth. It is possible that all of these processes are concurrent. The crystallographic relationship between the heterogeneously formed manganite with hematite, which has not been reported before, proves that hematite provides reaction sites and functions as an atomic template for the formation of MnO x nanowires. These findings advance our understanding of the redox chemistry and heterogeneous growth of minerals as controlled by the surficial structure of the substrate mineral. This has important geochemical implications as the catalytic growth of less common, highly reactive phases like MnO x are known to be consequential in complex natural and anthropogenic environments.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Exploring the impact of nucleotide length on lipid nanoparticle structure and properties

Lipid nanoparticles (LNPs) are versatile carriers for nucleic acid (NA) therapeutics, including ASOs, siRNA, mRNA, and poly-IC. While lipid composition is known to influence LNP properties, the impact of NA length on morphology and internal structure is less understood, particularly during the stages of carrier–cargo assembly. Here, we examine NA length and lipid composition immediately after mixing using high-throughput SAXS, dynamic light scattering, and cryogenic electron microscopy. All LNPs form ordered NA/lipid compartments, with longer NAs promoting inverse hexagonal (H II ) phases and larger intercompartment distances. In contrast, short NAs, especially in formulations with SM102 ionizable lipid, favor lamellar phases. SAXS peak deconvolution quantifies ordered versus disordered phases via a Robustness of Ordered Phase factor, which correlates with particle size and encapsulation efficiency. Formulations with MC3 ionizable and DOPE helper lipids exhibit the most stable H II -phase packing, highlighting the role of helper-lipid curvature in compartment stabilization. Variations in NA compartmentalization indicate differences in payload capacity, offering a framework for rational LNP design across diverse nucleic acid cargos.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Prostate Cancer Targeted X-Ray Fluorescence Imaging via Gold Nanoparticles Functionalized With Prostate-Specific Membrane Antigen (PSMA)

The gold nanoparticle (GNP) as a promising theranostic probe has been increasingly studied. The tumor-targeting efficiency of GNPs is crucial to increase the therapeutic ratio. In this study, we developed PSMA-targeted GNPs to enhance GNP uptake in prostate cancer and developed an x-ray fluorescence imaging system to noninvasively monitor and assess GNP delivery.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2022

Radiation Therapy Enhanced by NBTXR3 Nanoparticles Overcomes Anti-PD1 Resistance and Evokes Abscopal Effects

Radiation combined with PD1 blockade offers significant treatment benefits in several tumor types; however, anti-PD1 resistance precludes such benefits in many cases. Here we attempted to overcome anti-PD1 resistance by combining localized radiation with a radioenhancing nanoparticle (NBTXR3) and systemic anti-PD1 treatment to achieve abscopal effects in an anti-PD1–resistant mouse model of lung cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗