Nanophase Materials Research Articles

Microstructural Characterization of Porous Transport Layer Coatings

The porous transport layer (PTL) is a key component in polymer electrolyte membrane (PEM) water electrolyzers and serves the role of controlling the transport of reactants and products to and from the anode. Maintaining a low interfacial contact resistance between the titanium (Ti) fiber or sinter PTL and the iridium (Ir) anode catalyst is critical to maintaining the performance of the electrolyzer cell. This requires costly precious metal coatings, typically Pt, to inhibit the formation of native oxide layers during long-term cell operation. Strategies to reducing the thickness of these costly coatings including surface treatments, such as etching and abrasion, alternative low-cost coating materials, and implementation of microporous layers. It is crucial to understanding the morphologies and degradation mechanisms of these new strategies in order to accelerate the development of cheaper, more robust PTL coatings.In this work, correlative ex situ characterization methods, including laser confocal microscopy (LCM), focused ion beam (FIB), scanning electron microscopy (SEM), time-of-flight secondary ion mass spectrometry (ToF-SIMS), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM), are utilized to explore the impact surface treatments, such as etching and abrasion, on the Pt coatings uniformity and surface roughness. The thickness, local topography, and continuity of the Pt coating were quantified and correlated with interfacial contact resistance and electrochemical cell performance measurements. Changes to the thickness and composition of the coatings and oxide layers after single-cell tests will also be reported. Overall, these findings aim to guide the development of PTL treatments and coatings, ensuring the creation of highly durable and efficient PEM water electrolyzers that align with the U.S. Department of Energy's Hydrogen Shot goal of reducing the cost of clean hydrogen production to $1 per kilogram by 2031.Funding for this work was provided by U.S. Department of Energy Office of Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office through the H2NEW Consortium. Electron microscopy research conducted as part of a user project at the Center for Nanophase Materials Sciences (CNMS), which is a US Department of Energy, Office of Science User Facility at Oak Ridge National Laboratory.

(Invited) Electron Microscopy Investigation of PEM Electrolyzer Degradation at Low Iridium Loadings

The employment of hydrogen as an energy carrier provides a promising solution toward zero carbon emission and battling climate change. To meet the DOE’s Hydrogen Shot goal of $1 per kilogram of hydrogen by 2031, proton exchange membrane (PEM) water electrolysis is a key technology of hydrogen production from renewable energy sources. Successful deployment of PEM electrolyzers requires reducing cost while simultaneously improving performance and lifetime. While cost reduction is expected from a variety of strategies including scaling up, operation optimization, and advanced manufacturing, it remains vital to reduce the use of noble-metal catalyst due to its scarcity and vulnerable supply chain subject to market disturbance. [1]Reducing the loading of iridium catalyst on the anode while maintaining electrolyzer performance and durability is of great challenge. In this talk, we discuss issues in PEM electrolyzer component development and advanced manufacturing of electrode layers related to catalyst loading reduction with an emphasize on analytical electron microscopy which provides valuable insight on materials morphology, crystalline structure, and chemical compositions. The batch-to-batch variance of catalyst morphology and elemental composition/distribution from commercial suppliers will be examined for catalyst down-selection. We then analyze the effect of reducing Ir loading on the electrode layer structure and ionomer distribution. These results are correlated with electrochemical measurements in the electrolyzer cell, which help elucidate the effect of low catalyst loading on electrolyzer performance. Morphologies of degraded low-loading anode catalyst layer and gas recombination layers will be investigated, and the dissolution and migration of iridium will be studied. We will also examine impact of different roll-to-roll manufacturing strategies for low-loading catalyst layers and on electrolyzer durability. Last but not least, we analyze MEAs subject to cation contamination and recovery procedure with electron microscopy. [2]References[1] Alia, S.M., Current Opinion in Chemical Engineering 2021, 33:100703.[2] Funding for this work was provided by U.S. Department of Energy Office of Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office through the H2NEW Consortium. Electron microscopy research conducted as part of a user project at the Center for Nanophase Materials Sciences (CNMS), which is a US Department of Energy, Office of Science User Facility at Oak Ridge National Laboratory.

Exploring a New, Scalable Synthesis Route to Disordered Rock Salt (DRX) Cathode Materials

The global demand for lithium-ion batteries (LIBs) is ever-increasing as many nations seek to achieve a net carbon neutrality by the late 2030s. LiNi x Mn y Co1–x–y O2, (NMC) is one of the most widely-used Li-ion cathode active materials. Despite its excellent performance (e.g., reversible capacities up to ~220 mA h g–1 and 500+ cycles), NMC contains both Ni and Co, which are expensive and have vulnerable supply chains. Li-excess disordered rock salt (DRX) materials are promising new cathode materials that utilize earth-abundant transition metals such as Mn and Ti. Through a combination of cationic and anionic charge compensation, DRX materials can attain specific energies ≥700 Wh kg–1. Doping F– into the DRX structure (Li1+x Mn y Ti2–1–x–y O2–z F z ) has been reported to improve the material’s cycling stability. Despite their promising properties, most DRX cathodes are prepared through solid-state synthesis routes which require high-energy milling, provide little-to-no control over the particle morphology, and are difficult to scale.In this work, we developed a scalable combustion synthesis route (the glycine nitrate process) to produce high purity, high performance DRX cathodes. More specifically, we prepared two DRX precursors with nominal compositions of Li1.2Mn0.5Ti0.3O1.95 and Li1.2Mn0.7Ti0.1O1.85. When the precursors were heated under Ar to 1000 °C for 1 – 4 h, only 50% Li1.2Mn0.5Ti0.3O1.95 adopted a DRX structure, and no DRX formed for Li1.2Mn0.7Ti0.1O1.85. However, adding LiF to the precursors facilitates DRX phase formation during annealing and yields high purity DRX powders with the nominal compositions Li1.25Mn0.5Ti0.3O1.95F0.05 and Li1.35Mn0.7Ti0.1O1.85F0.15. In situ X-ray diffraction was employed to study the synthesis process, revealing DRX begins to form at just 600 °C, which is much lower than traditional solid-state routes. Furthermore, electrochemical tests on the Li1.35Mn0.7Ti0.1O1.85F0.15 cathode reveal these materials attain excellent performance with initial reversible capacities up to 215 mA h g–1 and stable cycling performance. These promising results demonstrate that combustion synthesis is a viable method for the scale-up of DRX materials.This research was conducted at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the U.S. Department of Energy (DOE) and was sponsored by the Vehicle Technologies Office (VTO) under the Office of Energy Efficiency and Renewable Energy (EERE). Some measurements were conducted at the Center for Nanophase Materials Sciences (CNMS), which is a DOE Office of Science User Facility.

Towards a Mechanistic Understanding of Transition-Metal Dissolution Phenomenon in Lithium-Ion Batteries

Dissolution of transition metals (TMs) from the layered NMC-type cathodes (LiNixMnyCozO2) occurs during cycling of lithium-ion full cells and is known to accelerate their capacity fade. This is because the dissolved metals migrate to the graphite anode and deposit there, where they accelerate irreversible active-lithium loss to reductive side reactions. The dissolution is known to get aggravated by cycling the cells to a greater upper cut-off voltage (UCV), where larger amounts of metals are typically found to be accumulated at the anode after long term cycling. At higher UCV oxygen loss from the cathode lattice also gets accelerated causing changes in the layered crystal structure at the surface level to a rock-salt and spinel mixture which has a very high impedance for Li-ion transport. Several other phenomena get accelerated as well, such as proton generation, and solvent decomposition etc. However, a complete mechanistic understanding of the how these phenomena impact the TM dissolution is lacking. For example, it is unclear whether the dissolution can occur in the charged state when the metals are in the oxidized state despite the presence of large number of acidic species, especially since most of the dissolved metal species typically detected in the electrolyte are in lower oxidation state. In this study, this question was targeted by aging the full graphite//NMC cells via long potentiostatic holds at UCV with/without any discharge steps, and recording the dissolved metals deposited at the graphite after aging. It is shown that a much greater amounts are deposited at the anode when discharge steps are included. Atomic structural changes from TM dissolution at the cathode surface corresponding to the two aging protocols in the charged/discharged state will also be presented.This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy (DOE) through Cathode-Electrolyte Interphase (CEI) Consortium. Part of the measurements was performed at the Center for Nanophase Materials Sciences (CNMS), which is sponsored at Oak Ridge National Laboratory by the Scientific User Facilities Division, Office of Basic Energy Sciences.

Integrating Polymer Electrolytes-Based Thick Composite Cathodes in All-Polymer Solid-State Lithium Metal Batteries

High energy density solid-state batteries require high areal loading composite cathodes (>4 mAh/cm2). However, increasing the cathode loading or thickness can introduce additional challenges apart from the expected rate capability limitations, which are much less pronounced in low loading or thin composite cathodes. These include greater volume changes during cycling at the cell level, which can introduce stresses at the various interfaces. While there are many successful reports showing long-term stable cycling of high loading composite cathode in all-inorganic solid-state cells, these cells are typically cycled under high pressures (>10 MPa), which may be impractical to commercialize. Such high pressures can alleviate the interfacial contact loss issues generated due to volume changes during cycling. Polymer electrolytes are non-rigid and can potentially accommodate strains to maintain contact at the interfaces during cycling, given sufficient adhesion. In this work, we will show some of the design strategies that were implemented to alleviate the contact loss issue at the polymer electrolyte separator/composite cathode interface in order to achieve stable cycling with thick polymer electrolyte-based composite cathodes in coil-cell configuration. Nickel-rich NMC (LiNixMnyCozO2) cathodes (NMC811 or 622) were used as the active materials. Since polymer electrolytes are known to be unstable with high voltage cathodes such as NMCs, the contribution of oxidative instability to the overall capacity decay will also be discussed by comparing two polymer electrolytes with different oxidative stability (a PEO-based dual-ion polymer electrolyte, and a single-ion polymer electrolyte). This research was sponsored by the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy for the Vehicle Technologies Office’s Advanced Battery Materials Research Program (Simon Thompson, Program Manager). A part of this research was sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory (ORNL), managed by UT-Battelle, LLC for the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. The SEM in this work was performed and supported at the Center for Nanophase Materials Sciences in Oak Ridge National Lab, a DOE Office of Science user facility.

Unleashing Novel Therapeutic Strategies for Dry Eye: Targeting ROS and the cGAS-STING Signaling Pathway with Tetrahedral Framework Nucleic Acids.

Dry eye affects majority of the global population, causing significant discomfort or even visual impairment, of which inflammation plays a crucial role in the deterioration process. This highlights the need for effective and safe anti-inflammatory treatments to achieve satisfactory therapeutic outcomes. This study focuses on the potential of tetrahedral framework nucleic acids (tFNA), a self-assembled nucleic acid material, as a simple and rapid treatment for oxidative stress and inflammation-induced disorders associated with dry eye. Mechanistically, tFNA is found to effectively alleviate dry eye damage by promoting corneal epithelial healing, restoring goblet cell function, and facilitating tear secretion recovery. Through RNA-seq analysis, it is observed that tFNA treatment normalizes the expression levels of most genes. Further exploration of the mechanism reveals that tFNA reduces excessive production of reactive oxygen species and modulates the inflammatory microenvironment, especially through cGAS-STING pathway thereby levels of inflammatory cytokines, including MMP9 and IL-6, are reduced. Additionally, tFNA demonstrates excellent safety performance without causing damage to the eye. Importantly, this study represents a successful application of nanophase materials with nucleic acid biological features for the effective treatment of dry eye, highlighting the potential clinical use of tFNA in the treatment of dry eye.

Experimental exploration of nano-phase change material composites for thermal management in Lithium-ion batteries

The present study reports an experimental investigation carried out for the thermal management of cylindrical lithium-ion battery simulators using aluminum oxide (nano particle)-eicosane (phase change material) composites. The experiment involves varying the power input from 4 to 10 W in 2 W increments and adjusting the weight percentage of nanoparticles (wt%) from 0.5 to 0.9 in 0.2 wt% intervals. The examination of battery temperature evolutions in response to heating power, a comprehensive heat transfer analysis incorporating the Nusselt number, the determination of the maximum temperature difference, thermal resistance analysis, and the exploration of temperature variations in the absence of Phase Change Material (PCM) are considered. The results show that an increase in the weight percentage of alumina nanoparticles in phase-change material cannot always improve the thermal performance. The results of the present study give guidelines for designing battery thermal management systems. The power levels used in the experiment vary from 4 W to 10 W in steps of 2 W. For a power level of 4 W, the heat flux is 1.088 kW/m2, and for a power level of 10 W, the heat flux is 2.72 kW/m2.

Numerical investigation of heat transfer improvement in a latent thermal energy storage system using a composite of phase change material and nanoparticles in a porous medium

In the present study, the flow field and heat transfer in an energy storage tank are simulated. The Phase Change Material (PCM) in the present study is paraffin, which is converted to a liquid phase by the introduction of a high-temperature fluid (80 °C) and then the cold fluid enters the flow-carrying tubes, causing the melt to freeze. In the freezing (discharge) phase, the heat released from it increases the temperature of the fluid. Tubes in tank configurations are also used in latent thermal energy storage, which also performs well in terms of heat transfer. In this research, the use of special geometry with special and practical boundary conditions in order to estimate the charging and discharging behavior of the process of melting and freezing nano-phase change materials in it, as well as the instantaneous examination of the temperature field, melting and freezing by using a computer code using the finite volume method, can distinguish the results of this research from other studies. The results of this research show that, the shape of the tube and storage tank is slightly different from the shell-tube type, in which the Heat Transfer Fluid (HTF) flows through the tubes and these tubes also pass through a PCM tank. The study of the effect of porosity coefficient of porous medium shows that the rate of phase changes in porous medium with porosity coefficient of 0.95 is more than porosity coefficient of 0.97. In addition, by adding nanoparticles to paraffin the melting process takes place in a short time. According to the results, the nanoparticles added to the PCM accelerate heat transfer while maintaining energy storage capacity.

Nanoengineering of Lanthanide‐Doped BaGdF5‐Graphene Oxide as a Tunable‐Nanocomposite Platform for Biological Applications

AbstractInorganic nanohosts doped with lanthanide ions are an indispensable tool for multimodal bioimaging and MRI applications due to their distinctive optical, magnetic, and biocompatible properties. Nanocomposites of such nanoprobes with functionalization capabilities could also enable their use in targeted therapy‐based applications. However, the influence of nanocomponents especially their proportion in a nanocomposite in modulating the physio‐chemical and biocompatibility properties of the nanocomposite is still elusive. To address this knowledge gap, we have engineered nanocomposites variants using an environmentally benign one‐step synthesis with ionic liquids. We have synthesized two nanocomposites, differing in the proportion of lanthanide‐doped ternary fluoride nanoparticles (as nanophase material with luminescent and magnetic traits) and graphene oxide (as host matrix phase with tunable functionalization potential for theranostics applications). We found that with increased GO nanomaterial, nanocomposites showed reduced crystallite size and photoluminescence properties without significantly affecting the magnetic traits. Thus, implying nanocomponents ratio has differential effect on the nanocomposite properties. To assess biocompatibility, we have employed sensitive biomarkers such as craniofacial development, cardiac rhythm, and overall survivability of zebrafish larvae. Remarkably, biocompatibility improved when the proportion of the GO was increased within the nanocomposite as compared to when the nanocomponents were assessed individually. Our results also revealed that biocompatibility of nanocomposites also depends on the synergistic interplay between the nanocomponents due to the spatial arrangement of each nanocomponent in the nanocomposites. Overall, our study offers an intriguing avenue for tuning the biocompatibility of such nanocomposites, rendering them as an application‐independent biocompatible‐platform for theranostics applications.

Enhanced performance and stability of a solar pond using an external heat exchanger filled with nano-phase change material

Salinity gradient solar ponds are a promising technology for harnessing/storing solar thermal energy. The energy storage capacity of solar ponds can be enhanced by incorporating phase change materials (PCMs). However, the low thermal conductivity of PCMs can negatively affect energy charging/discharging rates. In this study, an external energy storage system filled with CuO nanoparticle-enhanced PCM was employed to improve the performance and stability of a solar pond. The results were compared with water and pure PCM (paraffin) as control materials. Energy and exergy analysis was used to assess the effects of nanoparticles and their concentration on the overall solar pond performance. According to the results, the upper convective zone temperature remained consistent across all experiments and varied within the same range throughout the day. A slight temperature variation at specific times indicated the stability of the developed solar pond system. The system's exergy (energy) efficiency was increased from 10.72% (51.83%) for water to 14.71% (70.1%), 22.77% (82.13%), and 25.93% (87.58%) for PCM, PCM with 1 wt% nanoparticles, and PCM with 2 wt% nanoparticles, respectively. Incorporating nanoparticle-enhanced PCMs in external heat exchangers can effectively improve the stability and performance of solar pond systems.

Recent Trends and Scope of Nanotechnology in Orthopaedic Surgery: A Narrative Review

Orthopaedic implants osseointegrate better using nanophase materials because they mimic the natural trabecular bone structure better. Additionally, prostheses with nanophase coatings can lessen bacterial adherence compared to prostheses with traditional surfaces. Improved osseointegration and infection prevention may be possible with nano-coated joint replacement implants. Other potential applications with strong in-vitro findings include rapidly integrating fillers for osteochondral flaws, antitumour seleniumcoated endoprostheses, along with potent targeted Drug Delivery Systems (DDSs) for infection prevention and treatment of chronic overuse injuries. It is significant to focus on the use of nanotechnology in artificial joint replacement prostheses, drug delivery utilising nanotechnology, surgical oncology of the skeleton using nanotechnology, bone cell function using nanotechnology, applications in orthopaedic surgery, and, finally, the use of nanotechnology and its potential new fields of study for human welfare. Before nanophase devices are approved for clinical use, significant progress must be made in comprehending the potential health concerns associated with their creation, implantation, and usage habits. However, they have a lot of potential and will probably be helpful to all of us in the future. Nanotechnology is a fast-advancing area, and its applications in orthopaedic surgery are continually expanding. This review article enables academics, clinicians, and other stakeholders to stay up-to-date on the most recent advancements, innovations, and achievements in the integration of nanotechnology into orthopaedic operations. The article also focuses on the challenges of applying nanotechnology in orthopaedics, such as biocompatibility issues, regulatory hurdles, and financial considerations. Simultaneously, it can discuss potential avenues for further research, collaboration, and progress in overcoming these challenges. Discussing the practical applications and clinical consequences of nanotechnology in orthopaedic surgery is crucial. The evaluation can explore on how these improvements will affect patient outcomes, surgical techniques, and overall healthcare practices.

(Invited) Electron Microscopy Investigation of Electrolyzer Degradation

Low-temperature proton exchange membrane water electrolyzers (PEMWEs) are a key technology for green hydrogen production from renewable energy sources. Developing efficient and durable components for the membrane electrode assembly (MEA) at the heart of the electrolyzer is critical for meeting DOE’s Hydrogen Shot target of $1 per kg of hydrogen by 2031. Of key interest to the efficiency and longevity of the electrolyzer is the anode-side of the MEA, where the costly iridium (Ir) catalyst is prone to dissolution at the high potentials and acidic conditions experienced in the cell. Further, the interfacial contact resistance between the catalyst and porous transport layer (PTL) plays a key role in electrolyzer performance and can degrade over time. Understanding and mitigating these degradation modes is critical for reducing the cost the PEMWEs and enabling commercialization.Here we will present the results of electron microscopy characterization performed on degraded anode catalyst layers and coated PTLs. Cross sections of MEAs submitted to different cycling protocols (square wave, triangle wave, steady-state, etc.) were prepared by diamond-knife ultramicrotomy and studied with in the scanning transmission electron microscope (STEM). Using energy dispersive X-ray spectroscopy (EDS), the dissolution and migration of Ir into the membrane was tracked and correlated with performance losses. The impact of PTL contact area on inhomogeneous degradation in anodes with low catalyst loadings will also be presented. In addition, PTL coating thickness and uniformity will be correlated with interfacial contact resistance measurements using a combination of focused ion beam (FIB), scanning electron microscopy (SEM) and STEM-EDS.Funding for this work was provided by U.S. Department of Energy Office of Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office through the H2NEW Consortium. Electron microscopy research conducted as part of a user project at the Center for Nanophase Materials Sciences (CNMS), which is a US Department of Energy, Office of Science User Facility at Oak Ridge National Laboratory.

Materials Mitigation Strategies and Anode Catalyst Durability in Low Temperature Electrolysis

Hydrogen has unique advantages as an energy carrier, with a high energy density and capacity to facilitate both long term storage and conversion between electricity and chemical bonds. Although hydrogen currently has a significant role in transportation and agriculture, its use in the general energy landscape has been limited. With decreasing electricity prices, electrolysis cost reductions can be achieved and will enable an opportunity for greater use.[1] While load-following renewable power sources can reduce feedstock costs, further cost reductions can be achieved by reducing the platinum group metal (PGM) content.[2]Efforts are needed and underway to understand electrolyzer degradation and develop accelerated stress tests when accounting for lower PGM loadings and intermittent operation. In this presentation, studies related to different catalysts and catalyst layer properties, and their impact on electrolyzer performance and durability will be discussed. Catalysts with high metal content and less stable elements were generally found to be more susceptible to mobility and migration.[3] Materials have been evaluated, however, that can address catalyst degradation. These include catalyst development strategies such as crystallinity, structured morphologies, and supports, and electrode design strategies such as coating techniques and pore formers. In some cases this has led to increased site utilization and the spread of operational stressors through a larger portion of the catalyst layer, lessening performance losses over time. Testing of these materials has included more continuous operation and with applied accelerated stress tests, and it was found that certain materials may address load fluctuations in different ways. Perspectives on anode catalyst development will be discussed as they relate to the current status of materials mitigation strategies and anode catalyst layer degradation.[1] B. Pivovar, N. Rustagi and S. Satyapal, The Electrochemical Society Interface, 27, 47 (2018).[2] K. Ayers, N. Danilovic, R. Ouimet, M. Carmo, B. Pivovar and M. Bornstein, Annual Review of Chemical and Biomolecular Engineering, 10, 219 (2019).[3] Pivovar, B. S.; Boardman, R., H2NEW: Hydrogen (H2) from Next-generation Electrolyzers of Water. 2022.Acknowledgements: This research is supported by the U.S. Department of Energy, Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office under the auspices of the H2NEW consortium. Electron microscopy was performed at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility at Oak Ridge National Laboratory. The X-ray spectroscopy experiments were performed at beamline 10-ID at the APS, which is operated by the Materials Research Collaborative Access Team (MRCAT). MRCAT operations are supported by the Department of Energy and the MRCAT member institutions. The APS is a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.

Thermal transport properties of composite phase change materials characterized by molten carbonate-ceramic date nucleus occupancy structure: A molecular dynamics study

Carbonate molten salts play a crucial role in energy transmission and storage for concentrated solar power (CSP) plants. In this study, a design strategy employing a date nucleus occupation structure was proposed for carbonate molten salt/ceramic SiO2 composite phase change materials (PCMs). Molecular dynamics (MD) simulations were conducted to investigate the thermal transport properties and nanoscale atomic structure of the Nanocomposite phase change materials (NPCM) system. The findings revealed that the incorporation of SiO2 nanoparticles significantly reduced the melting point of NPCM system, offering a favorable way to regulate the operating temperature range of the system. Moreover, the thermal conductivity and specific heat capacity of NPCM system increased with the increase in the radii of nanoparticles, reaching up to 12.32% and 6.061%, respectively. However, it was observed that larger nanoparticles limited the migration of particles, leading to a decrease in the self-diffusion coefficient (D) of the system. This study provides valuable insights in the design and application of CSP power plants utilizing nano-phase change materials.

Experimental studies on the enhancement in discharging characteristics of phase change material with steatite nanoparticles

Phase change materials are latent heat energy storage systems that can store huge quantities of thermal energy in a small volume. Latent heat energy storage systems are complicated to design due to the low thermal conductivity of phase change materials for discharging to enhance the heat capacity and latent heat storage. The objective of the study is to examine the discharging of phase change material in a latent heat energy storage system for maintaining the temperature of the water. Paraffin wax utilized as the phase change material due to its higher latent heat capacity. The experiments were performed with the flow of the hot water through a phase change material container by using a copper tube to enhance the discharging of phase change material during solidification to maintain the temperature of the water. Furthermore, the steatite nanoparticle has been dispersed with phase change material to enhance the discharging of characteristics. The steatite nanoparticle has been selected due to its low thermal conductivity, and the weight percentages nanoparticles were varied viz. 10 %, 20 %, 30 %, and 40 %. The increase in water temperature from 0.1 °C to 1 °C has been taken 7 h by enhancing the discharging of phase change material with various concentrations of the steatite nanoparticle. The work shows the significant discharging characteristics of phase change material with steatite nanoparticles. The nano-phase change material has the potential to maintain the temperature of water without any external energy for a particular duration, which shows cost-effectiveness.

Electron Microscopy Investigation of Porous Transport Layer Coatings

The flow of reactants and biproducts to and from the anode in polymer electrolyte membrane (PEM) water electrolyzers is dictated by the properties of the porous transport layer (PTL). The PTL is made of titanium (Ti) fibers or sintered particles to provide stable thermal and electronic conduction pathways at the high overpotentials and acid conditions experienced at the anode. To prevent the formation of a thick native oxide on the Ti PTL surface, precious metal coatings are required. These coatings enable and maintain a reduced interfacial resistance between the PTL and catalyst layer. Understanding the impact of surface treatments and coatings on the morphology and composition of this interface is an important step to minimizing interfacial resistance, degradation and production costs. In this work, ion and electron beam techniques, including focused ion beam (FIB), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and scanning transmission electron microscopy (STEM), are used to investigate PTL coatings at the nanoscale.A series of fiber-type PTLs with a range of platinum (Pt) coating thicknesses were synthesized using physical vapor deposition. The uniformity of the coatings was analyzed using SEM-EDS in both plan-view and cross-section. Sections of individual fibers were then removed using FIB lift-out technique and thinned to less than 50 nanometers for further analysis by STEM. The thickness and uniformity of the Pt coating was quantified from STEM images for each Pt loading and correlated with interfacial resistance measurements. Changes to the thickness and composition of the coatings and oxide layers after single cell tests will also be reported alongside additional insights from correlative characterization approaches like atomic force microscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry. Overall, these findings will help steer the development of PTL treatments and coatings for highly durable and efficient PEM water electrolyzers towards meeting the U.S. Department of Energy’s Hydrogen Shot to reduce the cost of clean hydrogen production to $1 per kg by 2031.Funding for this work was provided by U.S. Department of Energy Office of Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office through the H2NEW Consortium. Electron microscopy research conducted as part of a user project at the Center for Nanophase Materials Sciences (CNMS), which is a US Department of Energy, Office of Science User Facility at Oak Ridge National Laboratory.

Impact of Calcium Doping of YBa2Cu3O7-δ Multilayer Thin Films on the Flux Pinning Landscape at 65–5 K, 0–9 T for Various Applications

An important research goal in the applications of high temperature superconductor YBa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7-δ</sub> (YBCO) thin films is increasing both the critical current density and also the isotropic nature of the film. YBCO is inherently anisotropic due to its layered perovskite structure. The critical current density of YBCO thin films is enhanced by increasing the flux pinning sites in the film by the addition of insulating nano-phase materials, such as BaZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> (BZO) nanorods, which are also anisotropic in nature. Using a multilayer pulsed laser deposition technique has been shown to produce films with inclusions that are more isotropic in nature. However, the defective BZO nanorod interface, resulting from its lattice mismatch with YBCO, prevents obtaining optimum pinning force. This research explores the effect of Ca doped YBCO space layers in the multilayer composite film, on the BZO nanorod/YBCO interface, over a wide range of conditions of 65–5 K and 0– 9T that are suitable for various applications. The interplay of combining these three variables: BaZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> addition to YBCO, multilayer film growth resulting from varying pulsed laser deposition conditions, and employing calcium doped YBCO space layers, and the resulting impact on film microstructures and superconducting properties, will be presented.

A novel reduced nano- phase change material based absorber for enhancing the water productivity and performance of solar desalination system

In present research work, two different types solar stills - conventional solar still and advanced solar still (ASS) have been studied. To enhance the yield (productivity) of ASS a nano-phase change material (ZnO-PCM) has been used. Conventional and advanced solar still performance is compared under same climatological conditions in two investigation sets. Maximum thermal efficiency and improved yield are obtained as 51% and 6600 ml/m2 for ASS-ZnO-PCM, respectively. Thus, cmulative yield of ASS-ZnO/PCM (6600 ml/m2) was nearly 113% more than conventional SS (3090 ml/m2.day). As a result, the productivity of ASS-ZnO/PCM has increased by about 36% employing the PCM.

Recent development in nano-phase change materials and their applications in enhancing thermal capacity of intelligent buildings: A state-of-the art review

Recent development in nano-phase change materials and their applications in enhancing thermal capacity of intelligent buildings: A state-of-the art review

Stable colonization of Akkermansia muciniphila educates host intestinal microecology and immunity to battle against inflammatory intestinal diseases

Gut microbial preparations are widely used in treating intestinal diseases but show mixed success. In this study, we found that the therapeutic efficacy of A. muciniphila for dextran sodium sulfate (DSS)-induced colitis as well as intestinal radiation toxicity was ~50%, and mice experiencing a positive prognosis harbored a high frequency of A. muciniphila in the gastrointestinal (GI) tract. Stable GI colonization of A. muciniphila elicited more profound shifts in the gut microbial community structure of hosts. Coexisting with A. muciniphila facilitated proliferation and reprogrammed the gene expression profile of Lactobacillus murinus, a classic probiotic that overtly responded to A. muciniphila addition in a time-dependent manner. Then, a magnetic-drove, mannose-loaded nanophase material was designed and linked to the surface of A. muciniphila. The modified A. muciniphila exhibited enhancements in inflammation targeting and intestinal colonization under an external magnetic field, elevating the positive-response rate and therapeutic efficacy against intestinal diseases. However, the unlinked cocktail containing A. muciniphila and the delivery system only induced negligible improvement of therapeutic efficacy. Importantly, heat-inactivated A. muciniphila lost therapeutic effects on DSS-induced colitis and was even retained in the GI tract for a long time. Further investigations revealed that the modified A. muciniphila was able to drive M2 macrophage polarization by upregulating the protein level of IL-4 at inflammatory loci. Together, our findings demonstrate that stable colonization of live A. muciniphila at lesion sites is essential for its anti-inflammatory function.