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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

Assembled peptoid crystalline nanomaterials as carbonic anhydrase mimics for promoted hydration and sequestration of CO 2

Carbonic anhydrase (CA) mimics have received significant attention due to their promising applications in the enhanced hydration and sequestration of CO 2 . Herein, we report the assembly of sequence-defined peptoids into crystalline nanomaterials with controlled microenvironment of active sites as CA mimics for promoted hydration and sequestration of CO 2 . By incorporating specific ligands into self-assembling peptoids and coordinating these ligands with metal cations, we synthesize a variety of crystalline nanosheets and nanotubes as efficient CA mimics comparable to natural bovine CA. Molecular dynamics simulations reveal the critical roles of peptoid-Zn 2+ binding energy and the active site local microenvironment on the catalytic performance of these CA mimics. CO 2 precipitation results show that these CA mimics promote the hydration and sequestration of CO 2 while retaining high thermal and chemical stabilities. This study offers essential guidance for the future design of high-performance CA-mimics suitable for applications in CO 2 capture and sequestration.

Chakma, Progyateg [Pacific Northwest National Labo↗
DOE OSTI2025

Magnetically responsive nanocultures for direct microbial assessment in soil environments

Cultivating microorganisms in native-like conditions is vital for bioprospecting and accessing now unculturable species. However, there remains a gap in scalable tools that can both mimic native microenvironments and enable targeted recovery of microbes from complex settings. Such approaches are essential to advance our understanding of microbial ecology, predict community functions, and discover previously unidentified biotherapeutics. We present magnetic nanocultures—a high-throughput microsystem for isolating and growing environmental microbes under near-native conditions. These nanoliter-scale bioreactors are encapsulated in semipermeable membranes that form magnetic polymeric microcapsules using iron oxide nanoparticles within polydimethylsiloxane-based shells. This design offers mechanical stability and magnetic actuation, enabling efficient retrieval from soil-like environments. The nanocultures are optimized for optical and biological properties to support microbial encapsulation, growth, and sorting. Our study demonstrates the feasibility of using magnetically responsive microenvironments to cultivate elusive microbes, offering a promising platform for bioprospecting previously uncultured or unknown microbial species.

Usman, Huda [Department of Chemical Engineering, C↗
DOE OSTI2024

Exploring the Photophysics of N-Type Polymer N2200

The polymer interphase is a complex environment comprised of polymer chains, solvent molecules, and electrolyte ions. However, the microenvironments that these ingredients produce is both poorly-understood and difficult to investigate given the system's inherent structural heterogeneity. Nonetheless, a fundamental understanding of the structure, electrochemical behavior, and excited-state dynamics is a key prerequisite to optimizing devices based on such a system - for instance, photoelectrochemical cells for the direct, light-driven production of solar hydrogen, which may minimize efficiency losses compared to sequential light harvesting and electrochemical hydrogen production in separate but linked devices. This work combines transient absorption (TA) spectroscopy, which is a powerful tool for the observation of a variety of excited states on a femto- to microsecond timescale, with time-resolved microwave conductivity (TRMC) spectroscopy, which selectively probes the dynamics of free charge carriers (FC), of a blend of a donor polymer (PTB7-Th) and acceptor polymer (N2200) in a bulk heterojunction. Initial results indicate an extension of FC lifetime and homogenization of the microenvironment on a whole-film level, not just at the surface of the polymer; however, many questions are still under active investigation, including the changes in energy of the involved polaron states, effective conjugation length, FC mobility and migration distance, etc. Additional experiments regarding the photoinitiated behavior of the blend in different environments and on different timescales are ongoing.

charge recombination↗
DOE OSTI2025

Modulating Iron Crystals with Lattice Chalcophile‐Siderophile Elements for Selective Dechlorinations Over Hydrogen Evolution

Selective dechlorination of organic chlorides over hydrogen evolution reaction (HER) remains a challenge because of their coincidence. Nanoscale zerovalent iron (nFe 0 ) draws a promising picture of in situ groundwater dechlorination, but its indiscriminate reactivity limits the application. Here, nFe 0 crystals are designed with electron shuttles and improved hydrophobic nature based on elemental chalcophile-siderophile characteristics, where chalcophile-siderophile S served as a bridge to allow impregnating nFe 0 crystals with weakly siderophile and strongly chalcophile Cu. Even impregnations of lattice chalcophile-siderophile elements into the nFe 0 crystals are evidenced at both intraparticle and individual-particle levels. The modulated Fe microenvironment and physicochemical properties broke the reactivity-selectivity-longevity-stability trade-off. Compared to nFe 0 , superhydrophobic Cu─S─nFe 0 with lattice expansion promoted dechlorination by 20-fold but inhibited HER by 150-fold, utilizing ≈80–100% electrons from the Fe 0 reservoir. This work demonstrates the concept of engineering nFe 0 lattice with tunable structure-property relationships, mimicking reductive dehalogenases by selectively interacting with halocarbon functional groups for efficient dehalogenation and sustainable groundwater remediation.

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

In-device Battery Failure Analysis

Lithium-ion batteries are indispensable power sources for a wide range of modern electronic devices. However, battery lifespan remains a critical limitation, directly affecting the sustainability and user experience. Conventional battery failure analysis in controlled lab settings may not capture the complex interactions and environmental factors encountered in real-world, in-device operating conditions. Here, this study analyzes the failure of commercial wireless earbud batteries as a model system within their intended usage context. Through multiscale and multimodal characterizations, the degradations from the material level to the device level are correlated, elucidating a failure pattern that is closely tied to the specific device configuration and operating conditions. The findings indicate that the ultimate failure mode is determined by the interplay of battery materials, cell structural design, and the in-device microenvironment, such as temperature gradients and their fluctuations. This holistic, in-device perspective on environmental influences provides critical insights for battery integration design, enhancing the reliability of modern electronics.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Plastic from CO 2 , Water, and Electricity: Tandem Electrochemical CO 2 Reduction and Thermochemical Ethylene-CO Copolymerization

Converting CO 2 into industrially useful products is an appealing strategy for utilization of an abundant chemical resource. Electrochemical CO 2 reduction (eCO 2 R) offers a pathway to convert CO 2 into CO and ethylene, using renewable electricity. Here, these products can be efficiently copolymerized by organometallic catalysts to generate polyketones. However, the conditions for these reactions are very different, presenting the challenge of coupling microenvironments typically encountered for the transformation of CO 2 into highly complex but desirable multicarbon products. Herein, we present a system to produce polyketone plastics entirely derived from CO 2 and water, where both the CO and C 2 H 4 intermediates are produced by eCO 2 R. In this system, a combination of Cu and Ag gas diffusion electrodes is used to generate a gas mixture with nearly equal concentrations of CO and C 2 H 4 , and a recirculatory CO 2 reduction loop is used to reach concentrations of above 11% each, leading to a current-to-polymer efficiency of up to 51% and CO 2 utilization of 14%.

carbon storage↗
DOE OSTI2025

Nonadditive CO 2 Uptake of Type II Porous Liquids Based on Imine Cages

Type II porous liquids can potentially exploit the fluidity of liquids and sorption properties of porous sorbents, yet CO 2 uptake in porous liquids is still poorly understood. Molecular simulations and experiments are used to examine CO 2 uptake by a prototypical porous liquid composed of porous organic cages (CC13) in 2′-hydroxyacetophenone (2′-HAP). The simulations are in reasonable agreement with experimental measurements of CO 2 solubility and provide unambiguous information on the partitioning of CO 2 within microenvironments in the liquid. Analysis of CO 2 dynamics is performed using these simulations, including assessing the self-diffusivity of CO 2 in both the neat solvent and porous liquid. This offers insights into the kinetics of CO 2 uptake and transport in type II porous liquids based on imine cages. Experiments with type II porous liquids formed by dissolving CC13 in three different size-excluded solvents show nonadditive CO 2 absorption relative to predictions based on ideal volume additivity. This nonadditive absorption behavior is also observed in simulations. Nonadditive CO 2 uptake is also demonstrated in type II porous liquids based on another imine-based porous cage, CC19.

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

Utilizing biochars to stabilize mercury in contaminated floodplain sediment: Implications on mercury remediation

Major weather events contribute to the mobility and remobilization of legacy mercury (Hg) contamination and sequestration within sediments. Remediation using biochar as a soil amendment is a useful technique to immobilize and decrease Hg toxicity. This study explored whether biochar application is effective at stabilizing labile mercury (LaHg) from floodplain sediment. Controlled mesocosms simulating contamination events and flooding conditions were conducted. Floodplain sediment, which experiences annual periodic flooding, was collected. Sediment was spiked with inorganic Hg, applied with different types of biochar, and experienced simulated flooding events. Four types of biochar, pure rice husk (RH), pure peanut hull (PH), sulfur-modified rice husk (SMRH), and sulfur-modified peanut hull (SMPH), were applied at 10 and 40 g/kg rates (i.e., RH 10, RH 40; PH 10, PH 40, SMRH 10, SMRH 40, SMPH 10, SMPH 40). Total Hg, methylmercury, and LaHg concentrations were analyzed by coupling with redox potential measurements. Results indicate that SMRH 10, PH 10, PH 40, SMPH 10, and SMPH 40 successfully remediate Hg by stabilizing and reducing LaHg species from floodplain sediment. However, a high Hg methylation potential was observed with unsulfated and sulfated peanut hulls (PH 10, PH 40, SMPH 10, and SMPH 40), as they tend to create a reducing microenvironment that favors sulfate reduction reactions. Additionally, sulfur-modified biochar tends to promote Hg methylation potential at high application rates (i.e., 40 g/kg). We thus recommend using SMRH at a relatively low application rate (SMRH 10) for the remediation of Hg from floodplain sediment.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Microbial O 2 consumption as a function of pore structure in soils of sorghum, switchgrass, and prairie vegetation systems

Abstract Microscale O 2 availability in soil, a main factor influencing microbial processing of soil carbon and nitrogen, is a function of O 2 diffusion and microbial O 2 consumption. While O 2 diffusivity is widely studied, it is difficult to quantify the rate of microbial O 2 consumption ( MO ). In this study, we quantified the MO using O 2 microsensor profiling to compare MO in different soils and vegetation systems while manipulating the soil pore structure. Soil samples were collected from three bioenergy vegetation systems, sorghum ( Sorghum bicolor L. Moench), switchgrass ( Panicum virgatum L.), and prairie, at an experimental site in Southeast Michigan, and from switchgrass and prairie systems at two sites in South and North Wisconsin. We prepared soil cores with two contrasting pore structures, that is, large (>30 µm Ø) pore‐dominated soil (LP) and small (<10 µm Ø) pore‐dominated soil (SP), from the same 1‐ to 2‐mm soil size fraction. We quantified MO (nmol O 2 cm −3 s −1 ) using a microprofiler with an oxygen (OX‐100 µm) microsensor (Unisense) pre‐ and post‐38‐day incubation. Across all studied systems, there was a trend for a decrease in SP MO post‐incubation, suggesting a change in microbial metabolism to lower O 2 utilization. However, sizeable microbial O 2 consumption continued in the LP soils, further corroborated by a positive correlation between the C‐CO 2 emission rate and the post‐incubation MO , highlighting that LP provided a better physical microenvironment for the soil microbes.

Chakraborty, Poulamee [Department of Plant Soil an↗
DOE OSTI2025

Cohort-based pan-cancer analysis and experimental studies reveal ISG15 gene as a novel biomarker for prognosis and immunotherapy efficacy prediction

Abstract ISG15, an interferon-stimulated ubiquitin-like protein, plays a multifaceted role in tumorigenesis and immune regulation. This study comprehensively evaluates ISG15 as a prognostic biomarker and predictor of immunotherapy response through pan-cancer bioinformatics analysis and experimental validation. By integrating multiomics data from TCGA, GEO, and clinical cohorts, we found that ISG15 is significantly overexpressed in multiple cancers and generally correlates with poor prognosis. Elevated ISG15 expression is associated with increased immune checkpoint gene expression, particularly PD-L1, and immune infiltration, notably M2-like tumor-associated macrophages. Immunohistochemistry and multiplexed immunofluorescence confirmed a strong positive correlation between ISG15, PD-L1, and M2-TAM infiltration in lung and gastric cancer samples. Functional analysis at the single-cell level revealed significant associations between ISG15 and tumor proliferation, angiogenesis, and immune suppression. Immunotherapy cohort analysis demonstrated that tumors with high ISG15 expression responded favorably to PD-L1 inhibitors but exhibited resistance to CTLA-4 blockade, findings further validated in lung cancer patients receiving anti-PD-1 therapy. These results suggest that ISG15 is a promising biomarker for prognosis and immunotherapy response prediction across cancers. Its integration into clinical decision-making may enhance personalized treatment strategies, improve immunotherapy outcomes, and provide new insights into the tumor immune microenvironment, cancer progression, and potential therapeutic targets for future drug development.

Immunology↗
DOE OSTI2026

Mechanically graded granular scaffolds for osteochondral tissue engineering

Engineered scaffolds designed to approximate the mechanical microenvironment of the osteochondral unit often address this complexity using discrete, two-phase architectures that introduce mechanical discontinuities and interfacial stress concentrations rather than a contiguous stiffness transition. To address this challenge, we created a photoannealed polyethylene glycol (PEG) granular scaffold with a spatially controlled stiffness gradient within a cell-permissive, macroporous architecture. Stiffness was dictated by photoannealing microgels using a photomask. We tuned void volume and available surface area by varying microgel diameter and tested how mesenchymal stromal cells (MSCs) interpret local mechanical environments. MSCs exhibited position-dependent differences in morphology, cytoskeletal structure, matrix deposition, and lineage-specific gene expression within the gradient scaffolds. Softer regions supported rounded cell morphology and deposition of a glycosaminoglycan-rich matrix, whereas stiffer regions promoted cell elongation, increased cytoskeletal tension, and expression of mineral-associated markers. Gradients formed from smaller microgels magnified these spatial responses by increasing cellular confinement and adhesion site availability. Disruption of actomyosin contractility eliminated these regional differences, demonstrating that MSCs rely on tension-dependent mechanotransduction to interpret the gradient. These findings reveal that coupling microgel architecture with continuous stiffness transitions provides a tractable platform to study multiscale mechanobiologic regulation and spatially guide osteochondral tissue formation.

Biological and medical sciences↗
DOE OSTI2024

Engineering a photoenzyme to use red light

Photoenzymatic reactions involving flavin-dependent “ene”-reductases (EREDs) rely on protein-templated charge transfer (CT) complexes between the cofactor and substrate for radical initiation. These complexes typically absorb in the blue region of the electromagnetic spectrum. Here, we engineered an ERED to form CT complexes that absorb red light. Mechanistic studies indicate that red-light activity is due to the growth of a red-absorbing shoulder off the previously identified cyan absorption feature. Molecular dynamics simulations, docking, and excited-state calculations suggest that the cyan feature involves a π→π* transition on flavin, whereas the red-light absorption is a π→π* transition between flavin and the substrate. Furthermore, differences in the electronic transition are due to changes in the substrate-binding conformation and allosteric tuning of the electronic structure of the cofactor-substrate complex. Microenvironment tuning of the CT complex for red-light activity is observed with other engineered photoenzymatic reactions, highlighting this effect’s generality.

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

Exploring new frontiers in type 1 diabetes through advanced mass-spectrometry-based molecular measurements

Type 1 diabetes (T1D) is a devastating autoimmune disease for which advanced mass spectrometry (MS) methods are increasingly used to identify new biomarkers and better understand underlying mechanisms. For example, integration of MS analysis and machine learning has identified multimolecular biomarker panels. In mechanistic studies, MS has contributed to the discovery of neoepitopes, and pathways involved in disease development and identifying therapeutic targets. However, challenges remain in understanding the role of tissue microenvironments, spatial heterogeneity, and environmental factors in disease pathogenesis. Recent advancements in MS, such as ultra-fast ion-mobility separations, and single-cell and spatial omics, can play a central role in addressing these challenges. Here, in this work, we review recent advancements in MS-based molecular measurements and their role in understanding T1D.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2025

Biogeochemical Controls on Wood Degradation as a Source of Bioavailable Carbon in Denitrifying Bioreactors

Woodchip bioreactors (WBRs) are important tools for the removal of nitrate in agricultural drainage, but their effectiveness is often limited by the slow degradation of lignocellulosic wood residues into bioavailable forms of carbon that fuel denitrifying microorganisms. Here, we examine biogeochemical factors regulating wood degradation in saturated woodchip beds, with a focus on the effects of dissolved oxygen (DO), iron (Fe), and manganese (Mn) in generating oxidative activity that can enhance wood decomposition. Woodchips from a 10-year-old WBR were characterized with bulk techniques and a novel combination of μX-ray scattering, μXRF, and μXANES to visualize the depletion of crystalline cellulose as a proxy for wood degradation. Woodchips from upstream portions of the reactor exhibited the greatest degradation, probably due to greater DO exposure, and degradation was localized to a 100 to 200 μm thick surface layer that was also associated with higher concentrations of Fe and Mn. Greater degradation was associated with faster nitrate removal. μXANES analysis of Fe and Mn in the surface layer indicated the presence of a microenvironment in which oxygenation reactions of Fe(II) and Mn(II) could contribute to the formation of reactive oxidants involved in the degradation of lignocellulose. In conclusion, our results provide new insight into biogeochemical properties that influence wood decomposition in WBRs at both micro- and macroscales and how these wood degradation processes are coupled with denitrification.

36 MATERIALS SCIENCE↗
DOE OSTI2025

A Perspective into Operando Methods for Probing Catalytic Interfaces

Rational design of electrocatalysts for (photo)electrochemical (PEC) processes like hydrogen and oxygen evolution and CO2 reduction reactions is aided by the recent improvements in capabilities of operando measurements, where morphology, composition, and/or function are probed during active catalysis. Through operando microscopy and spectroscopy, structure, catalytic microenvironment, oxidation state, adsorbates, and products can be measured to gain a better understanding of catalyst behavior and suggest possible improvements. Visualizing evolving catalyst morphologies, surface compositions, and electrochemical behavior also helps address many fundamental research questions for a better understanding of catalytic mechanisms. Correlating morphology with chemical identity or functional behavior using a variety of innovative microscopy methods is particularly promising for guiding development of next generation catalysts, and there are also many recent examples of using AI and robotics tools to innovate and speed development. In this Perspective, advances made over the past few years in operando imaging of catalysts relevant to solar fuels will be explored, followed by an outlook on technological developments in instrumentation, sample design, and computational power that may be applied to this field.

Catalysts↗
DOE OSTI2025

Assembly of Metalloporphyrin Peptoids into Crystalline Nanomaterials as a Multifunctional System for Biomimetic Catalysis and Sensing

While natural enzymes excel at catalysis and sensing, they often suffer from high cost and low stability in applications outside living systems. Among tremendous efforts made toward the design and synthesis of catalytic biomimetic materials, the approach of using crystalline nanomaterials assembled from sequence-defined polymers has emerged as a promising strategy. Herein, we report the assembly of metalloporphyrin peptoids into crystalline nanomaterials as a multifunctional system for biomimetic catalysis and sensing. The precise spatial positioning of covalently attached porphyrins within crystalline peptoid nanomaterials enables the mimicry of several enzyme active sites, including phosphotriesterase and horseradish peroxidase, for efficient catalytic hydrolysis and oxidation reactions. Additionally, the high programmability of these peptoid crystalline materials enables the creation and tuning of the active site microenvironment for enhanced catalytic activity. We further demonstrate the integration of responsive organic dyes into catalytic peptoid assemblies to achieve both detection and degradation of chemical warfare agent (CWA) mimics, even in the vapor phase. In conclusion, we expect this multifunctional system to provide tremendous opportunities in biomimetic catalysis and sensing, including the detoxification and detection of CWAs.

Catalysts↗
DOE OSTI2026

Electrolyte-Dependent, “Microscopically Irreversible” H-Atom Transfer Kinetics of Ce-Based Metal–Organic Framework, Ce-MOF-808

Redox reactions at the interface of metal oxides and protic electrolytes almost always involve protons and electrons in equal amounts. Given the stoichiometry, these proton-coupled electron transfer (PCET) reactions are thermochemically equivalent to net H-atom transfer (HAT) reactions. The correlation between the chemical nature of solid catalysts and HAT kinetics has been employed for decades as the design principle for energy-relevant reactions (e.g., reactions of 2H + /H 2 ). More recently, chemists have experimentally determined that a change in liquid electrolytes that alters the microenvironment at the redox-active sites has an equally profound impact on electrocatalysis involving PCET/HAT. Yet, precise correlations between the chemical nature of electrolytes and the PCET kinetics are, to date, rare in the literature. Herein, we report our findings using the Ce-based metal−organic framework, Ce-MOF-808, as a model system. Each Ce 6 (μ 3 −O) 4 (μ 3 − OH) 4 (OH) 6 (H 2 O) 6 node of this MOF undergoes a 1H + /1e − redox reaction. Using chronoamperometry and the Cottrell analysis, we have determined that the PCET hopping kinetics within the pores of Ce-MOF-808 can change by orders of magnitude by altering the buffer species and the proton activity of the electrolyte. Furthermore, in all buffers, reductive reactions were ∼3−10 times faster in kinetics than the reverse oxidative reaction with the same electrochemical driving force, suggesting that the system, at first glance, violates the principle of microscopic reversibility. Isothermal titration calorimetry (ITC) and computational simulations corroborated that the buffer-node binding thermodynamics are quite distinct, depending on the chemical nature of the buffer and the oxidation state of the node. Together, these results suggest that the substrate and the product during the oxidative vs reductive reaction of Ce-MOF-808 are chemically different species, which explains the apparent ‘microscopic irreversibility.’ Thus, the rational modulation of electrolytes can dramatically enhance PCET kinetics, even though the solid electrodes remain identical. Implications of these findings are contrasted with the electrochemical/electrocatalytic behavior of other redox-active MOFs, heterogeneous catalysts, and enzymatic systems at the solid−liquid interface.

Ce-based MOF↗
DOE OSTI2024

Mechanistic Insights into the Electrochemical Oxidation of 5-Hydroxymethylfurfural on a Thin-Film Ni Anode

The electrochemical oxidation of alcohols is being explored as a favorable substitute for the oxygen evolution reaction owing to its capability to generate high-value products and lower overpotentials. Herein, we present a systematic investigation into the electrochemical oxidation of 5-hydroxymethylfurfural (HMF), a model biomass platform chemical, on a thin-film nickel catalyst, aiming to investigate the underlying reaction mechanism and shed light on the role of the catalyst’s microenvironment and phase on activity and product selectivity. Utilizing a combined experimental and computational approach, we demonstrate that NiOOH is the active phase for HMF oxidation. Additionally, we find a substantial impact of the electrochemical environment, particularly the electrolyte pH, on the reaction. Under highly alkaline conditions (pH = 13), higher activity for HMF oxidation is observed, accompanied by an increased selectivity toward 2,5-furandicarboxylic acid (FDCA) production. Conversely, a less alkaline environment (pH = 11) results in diminished HMF oxidation activity and a higher preference for the partial oxidation product 2,5-diformylfuran (DFF). Mechanistic insights from DFT studies reveal that geminal diols that are present under highly alkaline conditions undergo hydride transfer via HMFCA, while a shift to an alkoxide route occurs at a lower pH, favoring the DFF pathway. Hydride transfer energetics are also strongly affected by the surface Ni oxidation state. Finally, this integrated approach, bridging experimental and computational insights, provides a general framework for investigating the electrochemical oxidation of aldehydes and alcohols, thereby advancing rational design strategies in electrocatalysts for alcohol electro-oxidation reactions.

30 DIRECT ENERGY CONVERSION↗