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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Chemical Vapor Deposition-Grown Hexagonal Boron Nitride and Graphene for Tandem Dielectric Capacitive Polymer Devices

To address the low energy density of polymeric capacitors, this work explores how tandem combinations of antagonistic properties can enhance energy storage. We introduce multilayer architecture integrating chemical vapor deposition (CVD)-grown ≈2 nm hexagonal boron nitride (hBN) and graphene with ferroelectric polyvinylidene fluoride (PVDF) and linear polyetherimide (PEI) layers to suppress leakage paths, reduce loss, and promote Maxwell–Wagner–Sillars polarization. Raman spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), and plasma focused ion beam (PFIB) analyses confirm robust material integration. In conclusion, for the tandem device, E BD ≈600 V/μm, while individual layers show lower values (PVDF|Graphene (Gr)|PVDF ≈ 50 V/μm and PEI|hBN|PEI ≈ 275 V/μm), yielding an overall ≈6000% enhancement and demonstrating the effectiveness of the 2D multilayer design.

Chemical vapor deposition (CVD)↗
DOE OSTI2024

Bench-Scale Testing of Monolithic PPI Structured Contactors for Direct Air Capture of CO 2

The overall project objective was to develop, optimize and bench-scale test the integrated embodiment of a leading direct air capture (DAC) sorbent composition, linear-poly(propylenimine) (l-PPI), in a structured material system, specifically a monolithic contactor for achieving low pressure drop, to justify its further scale-up in a subsequent program. The project team was led by CORMETECH, a leading monolithic gas/solid contactor manufacturer for environmental applications, and included Global Thermostat, a well-known DAC start-up, and Georgia Tech, a prominent US academic institution in carbon capture and DAC. The monolithic contactor for l-PPI in this project employed an advanced, cost-effective fabrication technique from CORMETECH, namely a porous monolith substrate directly impregnated with the amine, an approach contrasting to the traditional wash-coating methods used for activating monoliths. The l-PPI monolithic contractor is targeted for use in DAC systems such as the Global Thermostat DAC process, which involves the cyclic operation of ambient air flow over a monolithic amine contactor followed by steam-mediated thermal desorption and CO 2 collection, maximizing volumetric productivity while reducing the auxiliary power required to capture CO 2 from air. The Global Thermostat DAC process currently utilizes poly(ethyleneimine) (PEI) materials as baseline sorbents, which are subject to oxidative degradation and slow capacity fade at the elevated temperature required for efficient CO 2 removal. Georgia Tech, with Global Thermostat, had discovered in lab-scale efforts that l-PPI had superior resistance to oxidative degradation compared to PEI, with similar CO 2 adsorption capacity. While the novel l-PPI sorbent offers significant advantages over PEI for DAC, including potential design simplification and increased process efficiency, it is not commercially available, and prior to this project, had not yet been evaluated on the bench-scale in a structured contactor.

36 MATERIALS SCIENCE↗
NASA NTRS2026

Beyond Melting: Amorphous Bonding for Joining and Consolidation

Crystallization may be the hidden constraint in thermoplastic composite manufacturing. It requires tightly controlled cooling, induces residual stresses through shrinkage, and introduces path-dependent behavior that complicates predictive modeling yet remains essential for structural performance. This work asks: can bonding be achieved without relying on melt-driven crystallization? To address this, thin (5–20 μm) polyetherimide (PEI) interlayers are pre-healed to slow-cooled polyaryletherketone (PAEK) in two contexts. The first, Thermabond®, is sub-melt joining of low melt-PAEK laminates. Results show that bond quality is governed primarily by processing (i.e., adequate healing and film handling) rather than modest changes in interlayer thickness. This concept is then extended to laminate-scale manufacturing through an architecture known as OATMEAL (Out-of-autoclave Amorphous/semicrystalline Thermoplastic Material for Energy-efficient Aerospace-grade Laminates). PEI is healed to carbon fiber reinforced polyetheretherketone (PEEK) at the prepreg and excess PEI is then ablated from the surface. Crystallinity is developed off-line during prepreg fabrication, while subsequent consolidation occurs below the melt temperature to preserve it. Cross-ply warpage experiments show that, contrary to intuition, repeated amorphous interfaces reduce global curvature by lowering the effective stress lock-in temperature and eliminating crystallization shrinkage from the lamina response. Correspondingly, laminate behavior is accurately predicted using classical laminate theory (CLT) with a single effective stress-free temperature, whereas conventional CF/PEEK requires accounting for crystallization-driven effects. By decoupling interfacial healing from crystallization, OATMEAL enables sub-melt consolidation, reduces energy consumption by up to 75%, and increases manufacturing throughput by fivefold. These results demonstrate that amorphous bonding is not only a joining strategy, but a pathway to more predictable and scalable thermoplastic composite manufacturing.

solidification↗
DOE OSTI2026

Lewis Acid‐Activated Charge Trapping in Dielectric Polymers for Superior High‐Temperature Electrostatic Energy Storage

Dielectric polymer capacitors are essential for electrostatic energy storage but suffer from charge transport-induced energy losses, particularly at elevated temperatures where thermally activated charge carriers exacerbate conduction. Conventional mitigation strategies rely on introducing heterogeneous interfaces to create charge traps, complicating scalable film fabrication. A homogeneous molecular trapping mechanism would circumvent these complexities, yet remains underexplored. Herein, a charge trapping strategy is devised by modifying the lowest occupied molecular orbitals of dielectric polymers through Lewis acid-base adduct formation. The use of tris(pentafluorophenyl)boron (BCF) as a Lewis acidic molecular additive introduces deeper charge traps in commercial polyetherimide (PEI) while retaining homogeneity. With only 0.5 wt.% loading, the PEI-BCF film exhibits greatly improved breakdown strength, achieving an ultrahigh discharged energy density of 7.3 J cm-3 with excellent cycle stability at 200 °C. This work establishes a facile molecular approach to decoupling charge trapping from heterogeneous interfaces, enabling high-energy-density polymer capacitors operable under extreme thermal conditions.

Fan, Lu↗
DOE OSTI2025

Electrically Conductive Amine Functionalized Reduced Graphite Oxide Foam for CO 2 Removal from the Air

Rapid regeneration of CO 2 adsorbents is critical to improving the productivity of direct air capture (DAC) systems. In this study, we codesigned a material to have appropriate electrical conductivity and CO 2 adsorption properties to enable efficient CO 2 capture from air. Specifically, we present a poly(ethylenimine) (PEI)-impregnated thermally annealed graphite oxide (TAGO900) foam adsorbent tailored for vacuum-assisted electrically driven thermal swing adsorption (V-ETSA). This structured adsorbent leverages the high electrical conductivity of the reduced graphite oxide framework to enable fast and direct heating of the adsorbent material by electrical resistance heating (Joule heating). An optimal sample, 40 wt % PEI (molecular weight 25k) impregnated TAGO900, shows the best balance between adsorption capacity (1.54 mmol g –1 ) and adsorption rates (0.016 mmol g –1 min –1 ) using fixed bed breakthrough experiments at 25 °C and 70% RH using 50 sccm 400 ppm of CO 2 /N 2 flow. Compared to conventional temperature vacuum swing adsorption (TVSA), the V-ETSA approach achieves substantially faster CO 2 desorption, achieving average desorption rates (including cooling time) of 0.09 mmol g –1 min –1 ─approximately 2.5 times faster than TVSA under similar operating conditions. The maximum desorption rate reaches 0.23 mmol/g/min during the desorption stage. These results underscore the importance of the direct heating strategy, such as Joule heating, for fast and highly productive vacuum swing adsorption in DAC systems.

amines↗
DOE OSTI2026

Effect of Storage Conditions on Efficacy of Poly(ethylenimine)-Alumina CO 2 Sorbents

Solid amine sorbents are one of the primary components of DAC technologies that allow for the removal of ultradilute CO 2 from the atmosphere. A main drawback in the implementation of solid amine sorbents in industrial-scale DAC applications is their instability under certain operational or storage conditions over an extended period. In this work, the effect of storage temperature and gas composition in the storage headspace on the long-term stability of a poly(ethylenimine)-alumina (PEI/γ-Al 2 O 3 ) sorbent is explored. PEI/γ-Al 2 O 3 sorbents with 70 and 100% pore filling are aged under varying gases (N 2 , O 2 , Ar, 0.04% CO 2 −N 2 , CO 2 , and ambient air) in an oven (40 °C), at common ambient indoor temperature conditions (23 °C), or in a freezer (−4 °C). The CO 2 sorption capacity, as measured by thermogravimetric analysis (TGA), along with FTIR spectra of the fresh and aged sorbents, reveal that at 23 and −4 °C, storage under ambient air or inert gas (Ar) provides reasonable long-term stability, with <13% degradation over 12 and 5 months of storage. Interestingly, with storage at 40 °C, similar levels of deactivation were observed under pure O 2 and N 2 after 4 months of storage, which suggests that nonoxidative thermal reactions can occur under prolonged storage conditions under N 2 . In contrast, with storage under CO 2 , sorbent degradation is substantially suppressed compared to storage under N 2 , ambient air, O 2 , or Ar, yielding sorbents with no observable loss in capacity after 2 months, compared to a 66, 63, and 62% loss under N 2 , ambient air, and N 2 in the same period at 40 °C, respectively. Overall, these findings provide guidance for practical amine sorbent storage in academic or industrial settings where amine sorbents are used for carbon capture.

Atmospheric chemistry↗
DOE OSTI2026

Development of Next-Generation Additive Chemistry for Direct Air Capture Sorbents (CRADA Final Report)

Introducing antioxidant additives into amine-based DAC sorbents can extend their lifetime. These sorbents are readily prepared by physically mixing additives with amines, a straightforward approach using commercially available materials. Advancing this strategy requires understanding how additives function under varying conditions, especially humidity. This project aims to reveal how humidity and additive chemistry influence oxidative degradation of PEI-based sorbents, levereging LLNL’s expertise in physics-based computational modeling, and Global Thermostat (GT)’s expertise in materials synthesis, characterization, and degradation kinetics testing, to gain fundamental insights into the chemistries and mechanisms of PEI oxidative degradation, and develop design principles that enhance sorbent durability.

36 MATERIALS SCIENCE↗
NASA NTRS1988

Pultrusion with thermoplastics for the fabrication of structures in space

The use of the pultrusion method to produce structures in space is proposed. This technique is based on transporting materials in coils or bundles and fabricating the structures in space. Two methods for thermoplastic impregnation of advanced composite are described. The properties of three pultruded thermoplastic matrix materials, polyphenylene sulfide, polyetherimide (PEI), and polyetheretherketone (PEEK) are discussed and evaluated. It is observed that the pultrusions containing PEI and PEEK reveal post-fabrication potential of lightweight, high strength advanced composites and this method of fabrication produces strength values comparable to those of conventional techniques. Earth-based and space-based planetary shelter models are developed and compared. It is noted that cargo storage volume is dependent on a combination of profiles, packaging, and manufacturing methods.

Wilson, Maywood L.↗
DOE OSTI2025

Work In Progress: Using Internships as Means for Indirect Assessment of ABET Criteria 3 “1-7” Student Outcomes

The Electrical & Computer Engineering (ECE) Department at Portland State University (PSU) has developed a Power Engineering Internship (PEI) program that provides engineering career development pathways within the electric utility industry. The PEI is supported by several U.S. Department of Energy grants that aim to develop quality career opportunities and develop a future electric utility workforce that represents the nation’s diverse populations. The PSU ECE Department intends to use surveys of internship participants as assessment tools for its ABET accreditation process, in particular, the ABET Criteria 3 Student Outcomes (SOs). SOs relate to the knowledge, skills, and behaviors that students acquire as they progress through an engineering program [1]. They describe what engineering students are expected to know and should be able to do by the time they graduate. Engineering education literature presents multiple methods for using internships as means for assessing SOs. Methods include using self-assessments that derive from internship experiences as well as mapping survey responses from employers and interns to SOs. Such methods gain value as they are assessed over multiple years. However, the majority of this literature discusses assessment tools that were developed for the ABET 2000 Criteria 3 “a through k” SOs. One of our motivations is to provide assessment tools that can be used to assess modern Criteria 3 SOs based on students’ internship experiences.

Bass, Robert [Portland State University]↗
DOE OSTI2025

Work In Progress: Using Internships as Means for Indirect Assessment of ABET Criteria 3 "1-7" Student Outcomes

PSU operates the Power Engineering Internship program with funding from two U.S. Department of Energy grants. The program is operated in partnership with the lead organizations of these grants, an investor-owned utility, Portland General Electric (PGE), and the Confederated Tribes of the Warm Springs (CTWS). One of the programmatic goals of the PEI is to create and sustain a clean energy engineering workforce pipeline on behalf of these lead organizations. Both grants support internships at PGE, which is also a partner on the CTWS grant. The PEI provides engineering students with year-long internships, spanning both the academic year and the summer. The interns work at PGE facilities located throughout the Portland metropolitan area. Interns are employed full-time during summers and part-time during the academic year. Proximity of the worksites to the PSU campus enables the interns to participate in the program while attending school full-time. During the academic year, students average fifteen hours per week, adjusting their work schedule according to their academic workload. The interns are allocated 930 hours per year, 480 in the summer and 450 during the academic year, which they can plan as they see fit. The internships provide meaningful financial support for the students, who can earn up to $21k if they use all of their allocated hours. Such funding is particularly important for the typical student who attends a minority serving institutions,

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2025

Solid Amine CO2 Adsorbent Degradation: Insights from Experiments and Atomistic Simulations

Direct air capture (DAC) has received significant attention this decade as a viable solution to limit global warming, although large-scale deployment is currently not economically feasible. To reach the ambitious cost target set by the U.S. of $100/ton CO2 captured and stored, significant improvements must be made to sorbent lifetime and capacity. Aminosilanes grafted onto silica supports are promising candidates for deployment in DAC systems due to their relatively high oxidative stability and low regeneration temperature. Despite myriad advancements in the field, there still exists a fundamental knowledge gap relating sorbent structure to performance. In this work, we grafted various aminosilanes onto the highly porous silica SBA-15 and characterized both oxidative stability and CO2 capacity. Material properties systematically investigated included amine moiety (primary vs. secondary), silane group structure, number of linkages to the silica support, and co-addition of impregnated amines (e.g., PEI), among others. A fixed bed system was used to execute accelerated degradation studies in the presence of humidity and varying temperatures to simulate realistic operating conditions. Atomistic simulations were combined with the experimental results to gain mechanistic insight, ultimately informing the design of next-generation materials

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Laser-induced slip casting as an additive manufacturing approach for silicon carbide

Here, this work presents processing silicon carbide (SiC) with the laser-induced slip casting (LIS) additive manufacturing (AM). SiC was stabilized in water with polyethyleneimine (PEI) dispersant, and SiC slurries were made with rheology for LIS printing. High-density ceramic parts were printed, followed by single-step binder burnout and sintering. The printed parts achieved 93–95 % of theoretical density. X-ray computed tomography (XCT) revealed a small distribution of flaws exceeding 100 microns. The mechanical properties were measured in both parallel and perpendicular to the printing layers, and the orientation with layers perpendicular to the bending moment resulted in higher strength compared to the parallel direction. Porosity resulting from processing and large inclusions of boron carbide (B4C) were the root cause of failure in the measured samples. Despite these defects through this effort, this new approach demonstrates promise for green forming of SiC with densities greater than 95 % theoretical and tensile strengths above 250 MPa.

Additive Manufacturing↗
DOE OSTI2025

Engineering surface charges of nanofiltration membranes to maximize Li + /Mg 2+ separation properties

Polyamide-based nanofiltration (NF) membranes are attractive for Li + /Mg 2+ separation for lithium recovery from salt brine (containing mainly Mg 2+ ). However, Li + and Mg 2+ have similar hydration radii, resulting in a low separation factor (SF Li/Mg ). Herein, we demonstrate that SF Li/Mg can be significantly enhanced by optimizing the membrane surface positive charges. This results in an unexpected maximum SF Li/Mg at a solution pH slightly below its isoelectric point (IEP). Specifically, NF270 membrane was surface-grafted with 2-(methacryloyloxy)ethyltrimethylammonium chloride (META) or polyethylenimine (PEI) using bio-adhesive dopamine, forming a thin, stable, charged layer (20–40 nm) on the surface. The effects of solution pH and surface modification on the surface zeta potential (ZP) and single- and mixed-salt Li + /Mg 2+ separation properties are thoroughly investigated. For example, the META grafting increases the ZP from 9.2 to 16 mV and SF Li/Mg by 130 % from 35 to 80 at pH 4, superior to the state-of-the-art commercial NF membranes. Furthermore, this surface modification occurs at ≈22 °C in aqueous solutions and can be utilized to enhance commercial modules for practical applications.

Li+/Mg2+ separation↗
DOE OSTI2025

Evaluating Autoxidation Radical Scavengers and Additives to Enhance Aminopolymer Sorbent Stability

Solid amine sorbents have shown promise in the removal of ultradilute CO 2 from the atmosphere. Despite being a promising candidate material type for this application, these sorbents are prone to degradation during long-term exposure to environmental components such as CO 2 , O 2 , and H 2 O, with amine oxidation being a particularly challenging problem. In this study, we investigate the potency of different radical scavengers and additives in mitigating the degradation of a model poly- (ethylenimine) (PEI)/Al 2 O 3 sorbent under direct air capture (DAC)-relevant conditions. The results reveal that a 4,4′-bis(α,α- dimethylbenzyl)diphenylamine (BDDPA)-incorporated PEI/Al 2 O 3 sorbent showed the most resistance toward oxidative degradation at varying exposure times and BDDPA loadings under CO 2 -free air (21% O 2 /balance N 2 ) at 120 °C. Interestingly, under humid (∼43% relative humidity (RH) at 26 °C) and dry 0.04% CO 2 -air, the BDDPA/PEI/Al 2 O 3 sorbent showed enhanced sorbent stability both at 70 and 120 °C after 4.5 h of exposure. Under humid CO 2 -free air, at 120 °C, the antioxidant performance slightly declined (in comparison to the dry CO 2 -free air condition) but displayed a much higher stability than the pristine sorbent. Overall, the ability of BDDPA to inhibit sorbent degradation under dry and humid, CO 2 -free and CO 2 -containing (0.04%) air at intermediate (70 °C) and elevated (120 °C) temperatures is promising in prolonging sorbent stability and underscores the importance of performing accelerated oxidation studies in the presence of all species that are expected to be present in DAC processes to identify suitable stabilization treatments for sorbent materials.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Influence of Transition Metal Ion Contaminants on the Performance of Amine-Based Solid Sorbents in Direct Air Capture

Amine-functionalized solid sorbents are a class of sorbent materials proposed for direct air capture (DAC) of CO 2 , yet their long-term performance is susceptible to degradation under realistic operating conditions. Many amines are not thermodynamically stable in air, and amine sorbents oxidize while in use during DAC temperature swing adsorption processes. In this study, we investigate the role of transition metal ion contaminants, specifically Cu 2+ , Fe 2+ , and Ni 2+ , on the oxidative degradation of poly(ethylenimine) (PEI)-impregnated SBA-15 sorbents. By introducing metal ions via different modes mimicking both synthesis-related impurities and impurities derived from environmental exposure, we systematically evaluate sorbent stability after exposure to dry air at an elevated temperature. Thermogravimetric CO 2 uptake measurements reveal that even trace levels of Cu and Fe (as low as ∼4 ppm) can lead to measurable sorbent deactivation after oxidative aging, despite negligible loss in the performance of the control samples. In situ infrared, UV–vis, and X-ray photoelectron spectroscopies indicate that these metals catalyze radical-driven oxidation pathways, altering the chemical structure of the sorbent and accelerating degradation. Our findings underscore the need to account for trace metal contamination during DAC sorbent synthesis and deployment and highlight the importance of environmental contamination pathways.

CO2 capture↗
DOE OSTI2026

Stability of Metal–Organic Framework-Supported Amines under Exposure to Ozone Generated from Air

Amine compounds supported on porous materials such as metal–organic frameworks (MOFs) have shown promising performance for direct air capture (DAC) due to their enhanced affinity for CO 2 . Although features such as adsorption capacity and selectivity are paramount in these composites, their long-term stability has a major impact on the operating cost of DAC systems. In this work, changes in carbon capture performance, crystallinity, porosity and chemical environment of the constituting atoms of MOF-amine composites are explored after exposure to ozone and NOx impurities generated from corona discharge applied to air. From the obtained results, the stabilities of Mg 2 (dobpdc) (dobpdc 4– = 4,4′-dioxidobiphenyl-3,3′-dicarboxylate) grafted with ethylenediamine (en), N-methylethylenediamine (men), and N,N-dimethylethylenediamine (dmen), as well as MIL-101(Cr) MOF impregnated with polyethylenimine (PEI), are compared. A negative effect in the overall CO 2 adsorption capacity is observed for all MOF composites after exposure, as well as a decrease in the adsorption step pressure of CO 2 for Mg 2 (dobpdc) amine-grafted composites, as shown via dynamic gravimetric adsorption experiments. Spectroscopic analyses indicate that oxidation of amine groups through the formation of nitro functional groups occurs as well as a decrease in the electron-donation interaction between the supported amines and the metal nodes of the MOFs.

adsorption↗
DOE OSTI2025

CRADA Number NFE-22-09375 with Vitriform3D, Inc. (CRADA Final Report)

Each year, roughly 8 million tons of glass are landfilled in the United States. Vitriform3D, in collaboration with Oak Ridge National Laboratory through the Innovation Crossroads program, is developing an additive manufacturing approach to transform post-consumer glass into engineered stone building materials. A custom UV-curable binder jetting system was commissioned to enable recycled glass printing without energy-intensive oven curing. While this printer is still under development, the team pursued a parallel research track using ORNL equipment and a polyethyleneimine (PEI) binder. Printed parts were thermally post-cured and infiltrated with epoxy, with the resulting material exceeding fiber cement board performance. Silane treatment of the glass particles further improved glass–epoxy adhesion, yielding an additional 24% strength gain over the epoxy-glass composite, achieving nearly 3x the fiber cement benchmark. Ongoing research is focused on reducing epoxy content to improve cost and recycled content while retaining mechanical performance. This work demonstrates a scalable, low-carbon pathway to convert glass waste into high-value, locally produced construction materials.

36 MATERIALS SCIENCE↗