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Orbitrap LC-MS Analysis of Nanoparticle Composition at the EPCAPE Mount Soledad site between 04 18 2023 and 06 14 2023
Weekly peak lists containing m/z, intensity, and assigned formula for filter samples, size selected for sub-100 nm particles. Filters were collected daily between 4/18/23 and 6/14/23, grouped based on calendar week for extraction, and analyzed via Thermo Scientific Q Exactive Plus Orbitrap LC-MS. Formulas were assigned to background-corrected peak lists and restricted to CHONS/CHONSNa atoms for the negative and positive modes respectively. Filters were grouped into calendar weeks 0-8 with dates provided in README text file.
Online detection of airborne nanoparticle composition with mass spectrometry: Recent advances, challenges, and opportunities
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Reducing Agglomeration of Lab-Synthesized and Functionalized Barium Titanate Nanoparticle Composites
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Origin of Mechanical Enhancement in Polymer Nanoparticle (NP) Composites with Ultrahigh NP Loading
Polymer nanoparticle composites (PNCs) with ultrahigh loading of nanoparticles (NPs) (>50%) have been shown to exhibit markedly improved strength, stiffness, and toughness simultaneously compared to the neat systems of their components. Recent experimental studies on the effect of polymer fill fraction in these highly loaded PNCs reveal that even at low polymer fill fractions, hardness and modulus increase significantly. In this work, we aim to understand the origin of these performance enhancements by examining the dynamics of both polymer and NPs under tensile deformation. We perform molecular dynamics simulations of coarse-grained, glassy polymer in random-close-packed NP packings with a varying polymer fill fraction. We characterize the mechanical properties of the PNC systems, compare the NP rearrangement behavior, and study the polymer segmental and chain-level dynamics during deformation below the polymer glass transition. Finally, our simulation results confirm the experimentally observed increase in modulus at low polymer fill fractions, and we provide evidence that the source of mechanical enhancement is the polymer bridging effect.
Composite Materials with Magnetically Aligned Carbon Nanoparticles and Methods of Preparation
The present invention relates to magnetically aligned carbon nanoparticle composites and methods of preparing the same. The composites comprise carbon nanoparticles, host material, magnetically sensitive nanoparticles and surfactant. The composites may have enhanced mechanical, thermal, and/or electrical properties.
Composite Materials with Magnetically Aligned Carbon Nanoparticles Having Enhanced Electrical Properties and Methods of Preparation
Magnetically aligned carbon nanoparticle composites have enhanced electrical properties. The composites comprise carbon nanoparticles, a host material, magnetically sensitive nanoparticles and a surfactant. In addition to enhanced electrical properties, the composites can have enhanced mechanical and thermal properties.
Transmission Measurement of the Third-Order Susceptibility of Gold
Gold nanoparticle composites are known to display large optical nonlinearities. In order to assess the validity of generalized effective medium theories (EMT's) for describing the linear and nonlinear optical properties of metal nanoparticle composites, knowledge of the linear and nonlinear susceptibilities of the constituent materials is a prerequisite. In this study the inherent nonlinearity of the metal is measured directly (rather than deduced from a suitable EMT) using a very thin gold film. Specifically, we have used the z-scan technique at a wavelength near the transmission window of bulk gold to measure the third-order susceptibility of a continuous thin gold film deposited on a quartz substrate surface-modified with a self-assembled monolayer to promote adhesion and uniformity without affecting the optical properties. We compare our results with predictions which ascribe the nonlinear response to a Fermi-smearing mechanism. Further, we note that the sign of the nonlinear susceptibility is reversed from that of gold nanoparticle composites.
Metal Nanoparticle Aerogel Composites
We have fabricated sol-gels containing gold and silver nanoparticles. Formation of an aerogel produces a blue shift in the surface plasmon resonance as a result of the decrease in the dielectric constant of the matrix upon supercritical extraction of the solvent. However, as a result of chemical interface damping this blue shift does not obey effective medium theories. Annealing the samples in a reducing atmosphere at 400 C eliminates this discrepancy and results in narrowing and further blue shifting of the plasmon resonance. Metal particle aggregation also results in a deviation from the predictions of effective medium theories, but can be controlled through careful handling and by avoiding the use of alcohol. By applying effective medium theories to the heterogeneous interlayer surrounding each metal particle, we extend the technique of immersion spectroscopy to inhomogeneous materials characterized by spatially dependent dielectric constants, such as aerogels. We demonstrate that the shift in the surface plasmon wavelength provides the average fractional composition of each component (air and silica) in this inhomogeneous layer, i.e. the porosity of the aerogel or equivalently, for these materials, the catalytic dispersion. Additionally, the kinetics suggest that collective particle interactions in coagulated metal clusters are perturbed during silica gelation resulting in a change in the aggregate geometry.
Development of Bismuth and Platinum Bi-Metallic Nanoparticles to Enhance Melt Wire Temperature Resolution
Advanced manufacturing (AM) based on direct-write (DW) technologies has emerged as the predominant enabler for the fabrication of active and passive sensors to be deployed in harsh operating environments seen in a nuclear reactor. Recently, Idaho National Laboratory and Boise State University have recently established capabilities to incorporate advanced manufacturing (AM) methods to accelerate, modernize and enhance functionality of nuclear sensors and instrumentation to achieve the goal of enhancing the safety and efficiency of nuclear reactors. A significant thrust of this work includes the development of nuclear relevant feedstock materials compatible with a variety of direct-write processes for the development, fabrication and testing of AM sensors for peak temperature detection and neutron flux monitoring. For this report, bismuth and bismuth/platinum (BiPt) bi-metallic nanoparticles were synthesized using wet chemical approaches to develop bi-metallic feedstock materials to enhance the sensitivity of melt wires for peak temperature detection. Nanoparticle characterization was performed with Transmission Electron Microscopy (TEM) for nanoparticle composition and size, Transmission X-Ray Diffraction Fluorescence (TXRF) for nanoparticle composition, and Differential Scanning Calorimetry to elucidate the melting point of BiPt bi-metallic nanoparticles. Preliminary results indicate bi-metallic BiPt nanoparticles as a viable pathway for fabricating high resolution AM melt wires.
Control of nanoparticle dispersion, SEI composition, and electrode morphology enables long cycle life in high silicon content nanoparticle-based composite anodes for lithium-ion batteries
A 74 wt% silicon composite electrode delivers 1000 cycles with 74% capacity retention against NMC811 cathodes and a cell stack energy density of 212 W h kg −1 in a standard carbonate electrolyte with two simple chemical and process improvements.
Toward High Efficiency Water Processed Organic Photovoltaics: Controlling the Nanoparticle Morphology with Surface Energies
Here efficient organic photovoltaic devices fabricated from water-based colloidal dispersions with donor:acceptor composite nanoparticles achieving up to 9.98% power conversion efficiency (PCE) are reported. This high efficiency for water processed organic solar cells is attributed to morphology control by surface energy matching between the donor and the acceptor materials. Indeed, due to a low interfacial energy between donor and the acceptor, no large phase separation occurs during the nanoparticle formation process as well as upon thermal annealing. Indeed, synchrotron-based scanning transmission X-ray microscopy reveals that the internal morphology of composite nanoparticles is intermixed as well as the active layer morphology after thermal treatment. The PCE of this system reaches 85% that of devices prepared from chlorinated solvent. The gap between water-based inks and organic solvent-based inks gets narrower, which is promising for the development of eco-friendly processing and fabrication of organic photovoltaics.
Nanoparticle Hybrid Composites by RF Plasma Spray Deposition
A method of fabricating a composite material includes utilizing a radio frequency plasma process to form a plasma plume comprising nanoparticles. The nanoparticles may comprise boron nitride nanoparticles, silicon carbide nanoparticles, beryllium oxide nanoparticles, or carbon nanoparticles. The nanoparticles may comprise nanotubes or other particles depending on the requirements of a particular application. The nanoparticles are deposited on a substrate by directing a plasma plume towards the substrate. The nanoparticles are formed in the plasma plume immediately prior to being deposited on the substrate. The nanoparticles may form a mechanical bond with the fibers in addition to a chemical bond in the absence of a catalyst. The substrate may comprise a fiber fabric that may optionally be coated with a thin layer of metal. Alternatively, the substrate may comprise a solid material such as a metal sheet or plate.
Lubricant compositions comprising core-shell nanoparticles
Lubricant compositions, core-shell nanoparticles, and related methods are disclosed. In an exemplary embodiment, a lubricant composition includes a plurality of core-shell nanoparticles. The nanoparticles include a core, a first shell disposed on the core, and a second shell disposed on the first shell. The first shell is formed from a siliceous material and the second shell is formed from a hydrophobic material. The first and second shells form functional coatings that reduce wear and friction of parts lubricated with the lubricant composition.
SiO 2 Is Wasted Space in Single-Nanometer-Scale Silicon Nanoparticle-Based Composite Anodes for Li-Ion Electrochemical Energy Storage
The electrode processing conditions of silicon-based composite anodes play a pivotal role in the resulting interfacial chemical speciation and, thus, the electrochemical cycling behavior of the electrode. Systematically investigating how small chemical changes to the surface of the silicon nanoparticle (NP) affect larger, electrode-level properties is a strategy that will inform design principles to maximize electrode energy density and extend electrode lifetime. Here, we incorporate silicon nanoparticles (NPs) with an average diameter of 5.5 nm synthesized from the gas phase through a nonthermal plasma method into composite anode half-cell coin cells. We perform chemistry to functionalize the native hydride-terminated silicon NP surface with N-methylpyrrolidone (NMP) to improve slurry properties and reduce the silicon reactivity prior to composite electrode fabrication. We construct composite electrodes from these silicon NPs and observe an 86% capacity retention over 100 cycles at a rate of C/5, with an initial silicon specific capacity of 2600 mAh/g. We expose the same Si NPs to water that completely oxidizes these small-diameter NPs to SiO 2 and find that the SiO 2 NPs in the same electrode configuration exhibit no obvious lithium alloying capacity in the electrochemical potential range of lithium silicide alloy formation. As this result stands in contrast to existing literature, we provide a discussion on the origin of the discrepancies.
Methods for Preparing Nanoparticle-Containing Thermoplastic Composite Laminates
High quality thermoplastic composites and composite laminates containing nanoparticles and/or nanofibers, and methods of producing such composites and laminates are disclosed. The composites comprise a thermoplastic polymer and a plurality of nanoparticles, and may include a fibrous structural reinforcement. The composite laminates are formed from a plurality of nanoparticle-containing composite layers and may be fused to one another via an automated process.
Enhancing functionalities in carbon fiber composites by titanium dioxide nanoparticles
Carbon fiber composite's high specific strength makes it incredibly useful for structural applications. However, their low strain-to-failure can be problematic in structural applications that can potentially see high strain conditions or high fatigue cycles resulting in sudden, catastrophic failure. This is further complicated by damage manifesting within the composite thus not showing damage indicators on the surface. Therefore, monitoring the structural integrity and strain history of the composite in application by itself—while maintaining positive composite performance—is vital to ensure safe operation. In this study, a homogeneous dispersion of TiO 2 nanoparticles on carbon fiber is demonstrated to generate a piezoresistive carbon fiber polymer matrix composite with enhanced self-sensing capabilities. The nanoparticle-embedded composites also exhibited superior strength and damping potential compared to the nanoparticle-free composites. The apparent interlaminar shear strength increased by up to 15% and the damping loss factor increased by an average of 150% while the piezoresistive sensitivity increased by up to 180% with the addition of a small weight fraction of nanoparticles to the fiber surface. These results demonstrate an approach to simultaneously improve the sensing capabilities, damping behavior and mechanical strength of carbon fiber composites by simply adding nanoparticles in the fiber sizing using a commercially scalable deposition method.