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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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Manipulation and statistical analysis of the fluid flow of polymer semiconductor solutions during meniscus-guided coating

Recent work in structure–processing relationships of polymer semiconductors have demonstrated the versatility and control of thin-film microstructure offered by meniscusguided coating (MGC) techniques. Here, we analyze the qualitative and quantitative aspects of solution shearing, a model MGC method, using coating blades augmented with arrays of pillars. The pillars induce local regions of high strain rates—both shear and extensional—not otherwise possible with unmodified blades, and we use fluid mechanical simulations to model and study a variety of pillar spacings and densities. We then perform a statistical analysis of 130 simulation variables to find correlations with three dependent variables of interest: thin-film degree of crystallinity and transistor field-effect mobilities for charge-transport parallel (Μ para ) and perpendicular (Μ perp ) to the coating direction. Our study suggests that simple fluid mechanical models can reproduce substantive correlations between the induced fluid flow and important performance metrics, providing a methodology for optimizing blade design.

36 MATERIALS SCIENCE↗
DOE OSTI2022

In-situ polymerization to protect lithium metal electrodes

An electrode including an electrode active material including lithium (Li) and a polymer layer coating at least a portion of the electrode active material is provided. The polymer layer includes a polymerization product of a monomer having Formula I: where R1 and R2 are independently an aryl or a branched or unbranched C1-C10 alkyl and X1 and X2 are independently chlorine (Cl), bromine (Br), or iodine (I).

Li, Binsong↗
DOE OSTI2025

Patchy nanoparticles by atomic stencilling

Stencilling, in which patterns are created by painting over masks, has ubiquitous applications in art, architecture and manufacturing. Modern, top-down microfabrication methods have succeeded in reducing mask sizes to under 10 nm, enabling ever smaller microdevices as today’s fastest computer chips. Meanwhile, bottom-up masking using chemical bonds or physical interactions has remained largely unexplored, despite its advantages of low cost, solution-processability, scalability and high compatibility with complex, curved and three-dimensional (3D) surfaces. Here we report atomic stencilling to make patchy nanoparticles (NPs), using surface-adsorbed iodide submonolayers to create the mask and ligand-mediated grafted polymers onto unmasked regions as ‘paint’. We use this approach to synthesize more than 20 different types of NP coated with polymer patches in high yield. Polymer scaling theory and molecular dynamics (MD) simulation show that stencilling, along with the interplay of enthalpic and entropic effects of polymers, generates patchy particle morphologies not reported previously. These polymer-patched NPs self-assemble into extended crystals owing to highly uniform patches, including different non-closely packed superlattices. We propose that atomic stencilling opens new avenues in patterning NPs and other substrates at the nanometre length scale, leading to precise control of their chemistry, reactivity and interactions for a wide range of applications, such as targeted delivery, catalysis, microelectronics, integrated metamaterials and tissue engineering.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Increasing Volume in Conjugated Polymers to Facilitate Electrical Doping with Phosphomolybdic Acid

Molecular p-type electrical dopants have been proven useful to fine-tune the optoelectronic properties of bulk organic semiconductors and their interfaces. In this work, the volume in polymer films and its role in solution-based electrical p-type doping using phosphomolybdic acid (PMA) are studied. The polymer film volume was controlled using two approaches. One is based on heating both the PMA solution and the film prior to immersion. The second is based on coating the polymer film with a liquid blend that contains the PMA solution and a swelling solvent. 31 P NMR and FTIR experiments indicate that the Keggin structure appears to be preserved throughout the doping process. Results show that increasing the polymer volume facilitates the infiltration of the PMA Keggin structure, which results in an increased electrical p-type doping level.

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

Spray coating for washout tooling by binder jet additive manufacturing

We report washout tooling is a process in which a removable mold or fixture is disintegrated using a solvent. Binder Jet (BJ) additive manufacturing holds promise for creating customized washout molds from common materials. BJ-based washout tooling provides an advanced strategy in manufacturing fiber-reinforced composites (FRCs), especially for customized hollow FRCs. However, washout tools formed by BJ require an impermeable barrier between the porous tooling surface and the parts laid up on the surface to prevent the resin from infiltrating the tooling surface and bonding the tool to the FRC. The conventional method for preventing resin migration into the washout mold from the FRC is winding Teflon® tape over the entire surface, which is labor-intensive and very difficult to deploy for specific geometries. Here, we report the development of a polymer spray coating method to seal the tooling surface and prevent resin infiltration without affecting the washout properties needed for sacrificial tooling. Two water-soluble polymers, poly(sodium 4-styrenesulfonate) (PSS–Na) and poly(vinylsulfonic acid, sodium salt) (PVS–Na), were investigated for spray coating. PVS-Na maintained tighter geometric tolerances and provided excellent thermal stability with the onset of decomposition at 320 °C and glass transition temperature of 280 °C. Spray coating with PVS-Na streamlines the process of forming a protective layer for the washout molds by BJ, reduces migration of the resins from the FRC, and significantly improves the production efficiency of complex washout tools.

42 ENGINEERING↗
DOE OSTI2023

Catalytic Upgrading of Bio-based Furfural to 1,5-Pentanediol: A New Renewable Monomer for the Coatings Industry

This report summarizes the results of a collaborative effort between Oak Ridge National Laboratory (ORNL) and Pyran™ Inc. to utilize modeling capabilities developed by the CCPC (Consortium for Computational Physics and Chemistry) to assist Pyran in scaling up its proprietary process for thermocatalytic conversion of furfural to 1,5 pentanediol (PDO). Pyran’s bio-based PDO is a direct replacement for petroleum-based PDO and 1,6 hexanediol (HDO) currently used in polymers, additives, coatings, adhesives and sealants. The current market is in excess of $1B/yr. According to Pyran, their production process results in 95+% reduction in fossil CO 2 at lower production costs compared to the existing petroleum-based routes for PDO & HDO. Other chemicals based on intermediates from this process have current markets in excess of $10B/yr.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

DFO Computational Modeling Project - Catalytic Upgrading of Bio-based Furfural to 1,5-Pentanediol: A New Renewable Monomer for the Coatings Industry (Final Report)

This report summarizes the results of a collaborative effort between Oak Ridge National Laboratory (ORNL) and Pyran™ Inc. to utilize modeling capabilities developed by the CCPC (Consortium for Computational Physics and Chemistry) to assist Pyran in scaling up its proprietary process for thermocatalytic conversion of furfural to 1,5 pentanediol (PDO). Pyran’s bio-based PDO is a direct replacement for petroleum-based PDO and 1,6 hexanediol (HDO) currently used in polymers, additives, coatings, adhesives and sealants. The current market is in excess of $\$$1B/yr. According to Pyran, their production process results in 95+% reduction in fossil CO 2 at lower production costs compared to the existing petroleum-based routes for PDO & HDO. Other chemicals based on intermediates from this process have current markets in excess of $\$$10B/yr.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Impacts of catalyst nanolayers on water permeation and swelling of polymer electrolyte membranes

Polymer electrolyte membranes with catalyst layers are the most crucial components of proton exchange membrane (PEM) electrolyzer cells and fuel cells. Their water permeation and swelling behavior significantly impact the proton transport and performance in energy conversion devices. In this study, water permeations and swelling properties of Nafion membranes with different platinum (Pt) nanolayers under different conditions are investigated. Visualization results demonstrate the entire swelling process of Pt-coated Nafion membranes and reveal water transport in Nafion membranes and breakage of the Pt nanolayer. The water permeation of Nafion membranes with a 17 nm Pt nanolayer coating reduces from 40 to less than 20 umol min-1 cm -2 at 80 degrees C and 70 kPa differential pressure. The water permeation of Nafion membranes with a 36 nm Pt coating is slightly lower than one with a 17 nm Pt coating due to higher transport resistance through the thicker Pt nanolayer and smaller cracks on the Pt nanolayer. Nevertheless, the water permeation of Nafion membranes with Pt nanolayers is still in a good range for proton transport applications, demonstrating the feasibility of Pt or other metal coating on Nafion membranes as catalysts or substrates in PEM-based energy devices.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Experimental and computational design tools for industrial drying processes: Challenges in process‐limit prediction

Abstract The coating and drying of inks and slurries are important steps to manufacture a plethora of products. Drying processes, particularly, comprise energy‐intensive steps that affect product cost and quality. Prior work has highlighted failures of various multicomponent diffusivity models to conserve mass in dryer modeling and challenges in predicting process limits given variability in published values of key thermodynamic parameters. Herein, we develop a computational model and benchtop drying experiments to investigate these concerns for drying polymer‐laden coatings. Model predictions of process limits in a single‐zone drying oven demonstrate that published variability in Flory–Huggins parameter yields large variations in predicted operating temperatures above which blistering occurs. This indicates that caution should be exercised when choosing approaches to obtain or predict the Flory–Huggins parameter, and that both benchtop drying experiments and a set of additional experiments, such as sorption experiments, are needed to fully characterize and optimize a given drying process.

Parrish, Chance↗
DOE OSTI2020

Demonstration of Embedded Sensors in Ceramic Structures

The Transformational Challenge Reactor (TCR) program seeks to demonstrate an advanced 3D printed nuclear reactor core. A binder jet additive manufacturing process is used to fabricate the complex SiC ceramic components of the TCR core. After printing, the components are densified via chemical vapor infiltration (CVI). This process allows complex cavities to be created in which sensors can be placed at strategic locations. Inserting the sensors during the CVI process allows the sensors to be embedded within the component as it is infiltrated. The primary challenge for embedding the sensors is identifying the sensors and sensor sheath materials that can survive the temperatures (>1,000°C) and chemical exposure to H 2 and HCl during CVI. The embedded sensors that are being investigated for use during TCR operation include thermocouples, self-powered neutron detectors, and spatially distributed fiber-optic temperature sensors. This report describes the CVI materials compatibility tests and initial trials for embedding functional sensors. Mo is identified as the most suitable sensor sheath material based on its availability in small diameter tubing, relatively low neutron absorption cross section, and compatibility with H 2 , HCl, and the surrounding SiC matrix at the process temperatures. Amorphous SiO2 fiber-optic samples with Au and Cu metal coatings were successfully embedded in SiC along with bare fibers, although the metal coatings showed some evidence of localized melting during CVI. Initial experiments attempting to embed functional sensors showed that the sensors can be embedded in 3D printed SiC parts, but there are still challenges that must be overcome to ensure that the sensors and sensor sheaths do not fail during CVI. In particular, Nb-sheathed Mo-Nb thermocouples failed at temperatures far lower than expected despite thermodynamic calculations and materials compatibility tests that show the Nb sheath to be compatible with the CVI environment. One potential explanation for the large expansion of the Nb sheath could be related to hydride formation in the lower temperature region of the sheath. Future work will focus on Mo-sheathed thermocouples instead of Nb. The fiberoptic sensors tested during the instrumented experiment broke due to the lack of mechanical protection after their polymer-based coatings were vaporized. Future instrumented experiments will use metal-coated optical fibers for strain sensing to provide additional mechanical protection. However, custom coatings with higher melting points than commercially available Au and Cu might be required. Regardless, fiber-optic sensors are still candidates for spatially distributed temperature measurements since they can be inserted into an embedded metal sheath after CVI.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2025

Tuning Molecular Interactions between Peptoids and Substrates to Achieve Surface-Agnostic Coating

Achieving programmable and robust coatings that maintain functionality while adhering to various surface types with molecular-level tunability and programmable features remains challenging. In this study, we develop adaptable and stable surface-agnostic coatings (SACs) based on crystalline peptoid membranes by tuning interpeptoid and peptoid-substrate interactions. We utilize two complementary methods: (1) surfaceinduced assembly, where peptoid membranes form directly on substrates, and (2) depositing preformed peptoid crystalline membranes via an aqueous layer-by-layer (LbL) assembly technique. These strategies are applied to substrates with diverse surface chemistries and topographies, including mica, highly ordered pyrolytic graphite (HOPG), MoS 2 , sapphire, and porous membranes like porous alumina and polysulfide. Atomic force microscopy confirms the formation of peptoid coatings and reveals differences in assembly behavior across surfaces. Moisture vapor transport measurements serve as a proof-of-concept test for membrane continuity and tunable permeance. Together, these findings demonstrate the adaptability and programmability of peptoid-based SACs, enabling rational coating design on surfaces with diverse chemical and topographical features. Furthermore, this work opens pathways for using peptoid membranes as programmable surface modifiers in functional interfaces, protective coatings, and membrane platforms.

biomimetic polymers↗
DOE OSTI2025

Hydration and Restructuring of Polar Polymer Interfaces: Implications in Antifouling and Responsive Materials

Manipulating polymer interfaces is crucial for understanding how structure influences function in applications spanning biofouling prevention to energy storage. Moreover, observing how polymers adapt their microscopic structure to changes in their local environment can reveal essential properties that govern their performance in such applications, providing key insights into how to design more effective interfaces. Here, in this study, a series of “grafting-from” polymer brushes with side chains varying in charge, are probed by sum frequency generation (SFG) and modeled using all-atom molecular dynamics (MD) simulations to elucidate how chemical makeup and charge mediate interfacial restructuring in dry versus hydrated states. Results show that charge, in progressing from nonpolar to cationic to zwitterionic, results in dramatic changes in interfacial structure and overall hydration. While net neutral systems, regardless of bulk phase polarity, show minimal interfacial water structuring, the cationic species exhibits strong bulk water signals from the surface potential. Meanwhile, the polymer brushes themselves restructure in water differently independent of charge, impacting the functional groups that are presented to the aqueous phase. Nonpolar and cationic species for instance undergo a change in alkyl group orientations to accommodate hydrating water molecules, whereas the zwitterionic polymer becomes completely disordered in water. Overall, the structure-based behavior trends presented herein have implications in antifouling applications and responsive material interfaces.

biointerface↗
DOE OSTI2020

Polymer-derived SiC/C/Al environmental barrier coatings on carbon steel

Carbon steel is a widely used structural material; however, it lacks corrosion resistance in water environments. An alternative approach to overcome this challenge is to implement the deposition of inherently corrosion-resistant ceramic coatings. SiC/C/Al coatings were developed at 700°C, using polycarbosilane in combination with Al and C, which were included as active and passive fillers, respectively. Here, we show that it is necessary to use Al particle sizes below 10 µm for them to function as an active filler below 900°C. Owing to their laminar microstructure, these coatings showed a cohesive delamination with an adhesion strength of 10 MPa. Results demonstrated that these coatings were able to reduce the corrosion of carbon steel in saline water by 99.7%, with corrosion rates of 38.33 mpy for carbon steel, and 0.099 and 0.155 mpy for SiC/C and SiC/C/Al (10 µm) coatings, respectively.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Binder-Stabilized Carbon Fiber Hosts for High-Utilization Sodium–Polysulfide Flow Catholytes

Sodium-sulfur (Na-S) batteries hold promise as high-energy-density batteries for long-duration energy storage due to their high open circuit voltage and Earth-abundant active materials. However, low utilization of the sulfur active material limits the achievable specific capacity, especially when a liquid polysulfide catholyte is utilized. High-surface-area carbon materials demonstrate promise to increase sulfur utilization in a Na-S battery. To make the carbon host material applicable for a flow battery application, a binder is required to bind the carbon materials together and to a porous substrate. Here, we utilize a composite carbon paper electrode coated by polymer,carbon nanofibers (CNFs) and carbon black (CB). By varying the mass ratios of CNF to CB, we found that a 70/20/10 mass ratio of CNF/CB/binder provided the highest capacity (260 mAh g −1 compared to the baseline of 156 mAh g −1 ) and stable battery performance over 100 cycles. Analysis of the composite electrode and full cells reveals that the amount of CB in the composite electrode influences binder distribution, cell resistance, and full cell performance.

Lehmann, Michelle L. [Oak Ridge National Laborator↗
DOE OSTI2021

Application of Machine Learning to Improve Biobased Glucaric Acid Production (CRADA 504)

The Agile Biofoundry (ABF) is a multi-national lab consortium funded by the DOE Bioenergy Technologies Office that has developed a biofoundry that enables the rapid deployment of bioproducts into the market. Working with four ABF laboratory members (National Renewable Energy Laboratory (NREL), Pacific Northwest National Laboratory (PNNL), Lawrence Berkeley National Laboratory (LBNL), and Argonne National Laboratory (ANL)), Kalion will use advanced high throughput techniques, advanced analytics, and machine learning to optimize the production environment for glucaric acid. Low-cost, high-purity glucaric acid enables products in a wide range of fields to improve the chemical properties of products and applications ranging from water treatment, polymers & textiles, coatings, detergents, and pharmaceuticals. With its broad range of applications, glucaric acid has the potential to demonstrate how such bio-based materials offer great benefit to the US economy.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Application of Machine Learning to Improve Biobased Glucaric Acid Production: Cooperative Research and Development Final Report, CRADA Number CRD-20-17260

The Agile Biofoundry (ABF) is a multi-national lab consortium funded by the DOE Bioenergy Technologies Office that has developed a biofoundry that enables the rapid deployment of bioproducts into the market. Working with four ABF laboratory members (National Laboratory of the Rockies (NLR), Pacific Northwest National Laboratory (PNNL), Lawrence Berkeley National Laboratory (LBNL), and Argonne National Laboratory (ANL)), Kalion will use advanced high throughput techniques, advanced analytics, and machine learning to optimize the production environment for glucaric acid. Low-cost, high-purity glucaric acid enables products in a wide range of fields to improve the chemical properties of products and applications ranging from water treatment, polymers & textiles, coatings, detergents, and pharmaceuticals. With its broad range of applications, glucaric acid has the potential to demonstrate how such bio-based materials offer great benefit to the US economy.

09 BIOMASS FUELS↗