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Tag: Materials Science

  • KRICT has developed a breakthrough technology to achieve closed-loop recycling of textile wastes

    KRICT has developed a breakthrough technology to achieve closed-loop recycling of textile wastes

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    Newswise — The apparel industry accounts for 10% of global carbon emissions. The annual amount of fiber production reached 113 million tons in 2021* and the demand is increasing every year. However, almost 90% of post-consumer fiber wastes are disposed of through incineration or in landfills. Among these forms of waste, synthetic fiber has become a major threat to the environment and human health because, similar to other plastics, it is not biodegradable in nature. Owing to its low cost and durability, polyester is the most widely used synthetic fiber on the planet, accounting for more than half of all fabrics annually produced. Comprehensive recycling of polyester is thus a critical challenge for environmental sustainability and the health of future generations.

    *Source: Preferred Fiber & Materials Market Report 2022

    In practice, crude textile waste is not suitable for reuse or recycling because it is mixed with different fabric materials, colored by different dyes, and contaminated by various other impurities. Sorting it into homogeneous materials is necessary to make the waste recyclable by a chemical or mechanical method. To this end, the research team (P.I.: Dr. Joungmo Cho) in Korea Research Institute of Chemical Technology (KRICT) has developed a new chemical technology referred to as ‘chemical sorting’. This technology is applied to separate polyester from waste textiles that are disposed of in a mixed and contaminated form. In the process, a unique chemical compound, which selectively disrupts the chemical interaction between polyester and the dye used for its color, is used for the separation. The research team has also developed a new chemical recycling technology that consumes less energy than conventional methods to convert polyester into valuable monomers*, which can be repeatedly used for the synthesis of polymer materials.

    *monomer: a single molecular substance can react with other monomer molecules to form a polymer by chemical bonding

    Postconsumer clothes, made up of various materials with unknown compositions, are often discarded. They commonly comprise a variety of textiles such as cotton, wool, polyester, acrylic, nylon, elastane, and other blended fibers. Recycling cannot be achieved without sorting them into individual materials because of their incompatible chemical and physical properties. Industrially, the separation of individual materials from waste fabrics is accomplished by manual sorting, largely depending on human labor. This method has low accuracy and is unreliable and in turn fails to collect homogeneous materials, which is often critical for further steps of recycling. Recently, studies have been actively carried out to develop an automatic sorting machine, employing hyperspectral imaging technologies to acquire structural information of individual fabric targets. However, the sorting system still remains far from commercialization, mainly due to technical and economic barriers.

    The KRICT research team adopted an inexpensive and non-toxic biodegradable compound to chemically discriminate polyester from a mixture of waste fabrics. When the compound is applied to textiles. colorants only present in polyester are completely extracted while no significant changes occur in other materials. As a consequence, clean polyester can be separated from the mixture of colored fabrics. The method is applicable to select polyester from an uncolored fabric mixture as well. When uncolored fabric comes into contact with the waste colorants extracted from the sorting process, only polyester accepts the colorants while the other materials remain unchanged. As a consequence, the fabrics containing only polyester can be separated from mixed fabric waste in an inexpensive, accurate, and facile manner. The resulting sorted polyester can be used as clean feedstock for chemical recycling because the sorting method eliminates most organic impurities including intractable dyes.

    Chemical recycling, which converts polymer waste into the original building blocks, has potential to achieve circularity in recycling of polyester wastes whereas mechanical recycling can be used to produce only low quality material. In the conventional chemical recycling method, a high reaction temperature of above 200℃ is required to completely decompose polyester. Furthermore, energy-intensive purification steps are also inevitable in most commercial applications to obtain a high quality monomer product.

    The KRICT research team has developed a low-temperature glycolysis reaction system to convert chemically sorted waste polyester into pure bis(2-hydroxyethyl) terepthalate, which is an important building block monomer to produce new polymers. Monomer compounds obtained from the chemical recycling have quality equivalent to that derived from petroleum. Since the same compound as that used in ‘chemical sorting’ functions as an additive to lower the energy barrier of depolymerization, the reaction system can be easily and economically integrated with the chemical sorting technology for applications involving plastic or textile recycling where there is high demand for good product quality.

    Dr. Cho said, “Recently, the garment industry has utilized transparent and clean post-consumer PET bottles to produce recycled polyester clothes. However, this method is not sustainable because the material cannot be repeatedly recycled. In contrast, our current technology would not be limited by the complexity of the constituent materials or the initial level of impurity in the waste. Whether the targeted materials are derived from petroleum directly or recycled from waste, the technology can repeatedly process most post-consumer textile streams. Thus it will help reduce waste in landfills and substantially achieve a circular economy in the plastic and textile industries.”

    The chemical recycling technology has been licensed to Renew System Co., Ltd. (South Korea). Multidisciplinary R&D teams are now closely working together to build multi-scale facilities for the chemical recycling of waste clothing. A demonstration plant will be ready by the end of 2024 and commercial operation with an annual capacity of 10,000 tons is planned to start in 2025.

     

     

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    KRICT is a non-profit research institute funded by the Korean government. Since its foundation in 1976, KRICT has played a leading role to advance national chemical technologies in the fields of chemistry, material science, environmental science, and chemical engineering. Now, KRICT is moving forward to become a globally leading research institute tackling the most challenging issues in the field of Chemistry and Engineering and will continue to fulfill its role in developing chemical technologies that benefit the entire world and keep our earth healthy. More detailed information on KRICT can be found at https://www.krict.re.kr/eng/

    This study was supported by the Materials/Parts Technology Development Program funded by the Ministry of Trade, Industry & Energy (MOTIE, Republic of Korea) and by the Institutional Program of the Korea Research Institute of Chemical Technology (KRICT). The research was published in ACS Sustainable Chemistry & Engineering, volume 10 (51) and featured on the front cover of the volume.

    Credit: Korea Research Institute of Chemical Technology (KRICT)

    Usage Restrictions of Multimedia (Attachment File): The sources of photos and research results from KRICT must be specified

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    National Research Council of Science and Technology

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  • Knots smaller than human hair make materials unusually tough

    Knots smaller than human hair make materials unusually tough

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    Newswise — In the latest advance in nano- and micro-architected materials, engineers at Caltech have developed a new material made from numerous interconnected microscale knots.

    The knots make the material far tougher than identically structured but unknotted materials: they absorb more energy and are able to deform more while still being able to return to their original shape undamaged. These new knotted materials may find applications in biomedicine as well as in aerospace applications due to their durability, possible biocompatibility, and extreme deformability.
     
    “The capability to overcome the general trade-off between material deformability and tensile toughness [the ability to be stretched without breaking] offers new ways to design devices that are extremely flexible, durable, and can operate in extreme conditions,” says former Caltech graduate student Widianto P. Moestopo (MS ‘ 19, PhD ’22), now at Lawrence Livermore National Laboratory. Moestopo is the lead author of a paper on the nanoscale knots that was published on March 8 in Science Advances.

    Moestopo helped develop the material in the lab of Julia R. Greer, the Ruben F. and Donna Mettler Professor of Materials Science, Mechanics and Medical Engineering; Fletcher Jones Foundation director of the Kavli Nanoscience Institute; and senior author of the Science Advances paper. Greer is at the forefront of the creation of such nano-architected materials, or materials whose structure is designed and organized at a nanometer scale and that consequently exhibit unusual, often surprising properties.
     
    “Embarking on understanding how the knots would affect the mechanical response of micro-architected materials was a new out-of-the-box idea,” Greer says. “We had done extensive research on studying the mechanical deformation of many other types of micro-textiles, for example, lattices and woven materials. Venturing into the world of knots allowed us to gain deeper insights into the role of friction and energy dissipation, and proved to be meaningful.”
     
    Each knot is around 70 micrometers in height and width, and each fiber has a radius of around 1.7 micrometers (around one-hundredth the radius of a human hair). While these are not the smallest knots ever made—in 2017 chemists tied a knot made from an individual strand of atoms—this does represent the first time that a material composed of numerous knots at this scale has ever been created. Further, it demonstrates the potential value of including these nanoscale knots in a material—for example, for suturing or tethering in biomedicine. 
     
    The knotted materials, which were created out of polymers, exhibit a tensile toughness that far surpasses materials that are unknotted but otherwise structurally identical, including ones where individual strands are interwoven instead of knotted. When compared to their unknotted counterparts, the knotted materials absorb 92 percent more energy and require more than twice the amount of strain to snap when pulled. 
     
    The knots were not tied but rather manufactured in a knotted state by using advanced high-resolution 3D lithography capable of producing structures in the nanoscale. The samples detailed in the Science Advancespaper contain simple knots—an overhand knot with an extra twist that provides additional friction to absorb additional energy while the material is stretched. In the future, the team plans to explore materials constructed from more complex knots.
     
    Moestopo’s interest in knots grew out of research he was conducting in 2020 during the COVID-19 lockdowns. “I came across some works from researchers who are studying the mechanics of physical knots as opposed to knots in a purely mathematical sense. I do not consider myself a climber, a sailor, or a mathematician, but I have tied knots throughout my life, so I thought it was worth trying to insert knots into my designs,” he says.
     
    The paper has a tongue-in-cheek title—“Knots are Not for Naught: Design, Properties, and Topology of Hierarchical Intertwined Microarchitected Materials.” Co-authors include Caltech graduate students Sammy Shaker and Weiting Deng. This research was funded by the National Science Foundation through Moestopo’s Graduate Research Fellowship Program, Caltech’s Clinard Innovation Fund, Greer’s Vannevar Bush Faculty Fellowship, and the Office of Naval Research.

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    California Institute of Technology

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  • A 4D printer for smart materials with magneto-and electro-mechanical properties has been developed

    A 4D printer for smart materials with magneto-and electro-mechanical properties has been developed

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    Newswise — Researchers at Universidad Carlos III de Madrid (UC3M) have created software and hardware for a 4D printer with applications in the biomedical field. In addition to 3D printing, this machine allows for controlling extra functions: programming the material’s response so that shape-changing occurs under external magnetic field, or changes in its electric properties develops under mechanical deformation. This opens the door to the design of soft robots or smart sensors and substrates that transmit signals to different cellular systems, among other applications.

    This research line focuses on the development of soft multifunctional structures, which consist of materials with mechanical properties that mimic biological tissues such as the brain or skin. In addition, they are capable of changing their shape or properties when actuated via external stimuli, such as magnetic fields or electric currents.

    Until now, this team of researchers had made several advances in the design and manufacturing of these structures, but they were very limited in terms of shape-design and programming of intelligent responses. The work presented in their latest study, published in the journal Advanced Materials Technologies, has allowed them to open up new possibilities by developing a novel4D printing methodology. “This technology allows us to not only control the way we print three-dimensional structures, but also to give them the ability to change their properties or geometry in response to the action of external magnetic fields, or the ability to modify their electric properties when they deform”, explains one of the researchers, Daniel García González, head of the ERC 4D-BIOMAP (GA 947723) project and associate professor in UC3M’s Department of Continuum Mechanics and Structure Theory.

    This type of printing is complex since the material to be extruded transitions from liquid to solid during the printing process. It is therefore necessary to understand the material dynamics to adapt the manufacturing process and obtain a material which is sufficiently liquid when it flows through the printer nozzle but, at the same time, solid enough to maintain a specific shape. To this end, they have developed an interdisciplinary methodology that combines theoretical and experimental techniques allowing them to build the printing device from scratch, both the physical part of the device (the hardware) and the computer programmes that allow it to be controlled (the software).

    A self-healing material

    The researchers have also developed a new material concept that is capable of healing itself autonomously without the need for external action, according to another recent publication in the journal Composites Part B: Engineering. “This material consists of a soft polymer matrix embedded with magnetic particles with a remanent field. For practical purposes, it is as if we had small magnets distributed in the material, so that, if it breaks, when the resulting parts are brought together again, they will physically join recovering their structural integrity”, says Daniel García González.

    Thanks to these advances, which have led to several registered patents, these scientists have been able to print three types of functional materials: some that change their shape and properties in response to external magnetic fields; others with self-healing capability; and others whose electrical properties (conductivity) vary according to their shape or deformation. With the first type of material, they have developed smart substrates to transmit forces and signals to cellular systems, so that they can influence biological processes such as cell proliferation or migration. These materials can also be used to design soft robots whose performance can be controlled by magnetic fields.

    The combination of materials with self-healing capabilities and whose electric conduction properties vary with deformation opens up enormous possibilities in the development of sensors. “We can think of sensors that, attached to our body, collect information about our movement from variations in electric conductivity. In addition, the material’s self-healing capability allows the design of sensors with binary signals. For example, if we have had a knee injury and need to limit rotation to a maximum value, we can incorporate a small band of this material over our joint. This way, when we exceed this maximum rotation, the material will break showing an abrupt change in its electric properties, thus providing a warning signal. However, when returning the knee to a relaxed state, the material’s healing capability will result in recovery of the electric signal. This way we can monitor our movements and warn of risky conditions after surgery or during rehabilitation periods”, says Daniel Garcia González.

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    Universidad Carlos III de Madrid

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  • 12 exotic bacteria found to passively collect rare earth elements from wastewater

    12 exotic bacteria found to passively collect rare earth elements from wastewater

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    Newswise — Rare earth elements (REEs) are a group of 17 chemically similar metals, which got their name because they typically occur at low concentrations (between 0.5 and 67 parts per million) within the Earth’s crust. Because they are indispensable in modern technology such as light emitting diodes, mobile phones, electromotors, wind turbines, hard disks, cameras, magnets, and low-energy lightbulbs, the demand for them has increased steadily over the past few decades, and is predicted to rise further by 2030.

    As a result of their rarity and the demand they are expensive: for example, a kilo of neodymium oxide currently costs approximately €200, while the same amount of terbium oxide costs approximately €3,800. Today, China has a near-monopoly on the mining of REEs, although the discovery of promising new finds (more than one million metric tons) in Kiruna, Sweden was announced with great fanfare in January 2023.

    Circular economy

    The advantages of moving from a wasteful ‘linear’ economy to a ‘circular’ economy, where all resources are recycled and reused, are obvious. So could we recycle REEs more efficiently, too?

    In Frontiers in Bioengineering and Biotechnology, German scientists showed that the answer is yes: the biomass of some exotic photosynthetic cyanobacteria can efficiently absorb REEs from wastewater, for example derived from mining, metallurgy, or the recycling of e-waste. The absorbed REEs can afterwards be washed from the biomass and collected for reuse.

    “Here we optimized the conditions of REE uptake by the cyanobacterial biomass, and characterized the most important chemical mechanisms for binding them. These cyanobacteria could be used in future eco-friendly processes for simultaneous REE recovery and treatment of industrial wastewater,” said Dr Thomas Brück, a professor at the Technical University of Munich and the study’s last author.

    Highly specialist strains of cyanobacteria

    Biosorption is a metabolically passive process for the fast, reversible binding of ions from aqueous solutions to biomass. Brück and colleagues measured the potential for biosorption of the REEs lanthanum, cerium, neodymium, and terbium by 12 strains of cyanobacteria in laboratory culture. Most of these strains had never been assessed for their biotechnological potential before. They were sampled from highly specialized habitats such as arid soils in Namibian deserts, the surface of lichens around the world, natron lakes in Chad, crevices in rocks in South Africa, or polluted brooks in Switzerland.

    The authors found that an uncharacterized new species of Nostoc had the highest capacity for biosorption of ions of these four REEs from aqueous solutions, with efficiencies between 84.2 and 91.5 mg per g biomass, while Scytonema hyalinum had the lowest efficiency at 15.5 to 21.2 mg per g. Also efficient were Synechococcus elongates, Desmonostoc muscorum, Calothrix brevissima, and an uncharacterized new species of Komarekiella. Biosorption was found to depend strongly on acidity: it was highest at a pH of between five and six, and decreased steadily in more acid solutions. The process was most efficient when there was no ‘competition’ for the biosorption surface on the cyanobacteria biomass from positive ions of other, non-REE metals such as zinc, lead, nickel, or aluminium.

    The authors used a technique called infrared spectroscopy to determine which functional chemical groups in the biomass were mostly responsible for biosorption of REEs.

    “We found that biomass derived from cyanobacteria has excellent adsorption characteristics due to their high concentration of negatively charged sugar moieties, which carry carbonyl and carboxyl groups. These negatively charged components attract positively charged metal ions such as REEs, and support their attachment to the biomass,” said first author Michael Paper, a scientist at the Technical University of Munich.

    Fast and efficient, with great potential for future applications

    The authors conclude that biosorption of REEs by cyanobacteria is possible even at low concentrations of the metals. The process is also fast: for example, most cerium in solution was biosorbed within five minutes of starting the reaction.

    “The cyanobacteria described here can adsorb amounts of REEs corresponding to up to 10% of their dry matter. Biosorption thus presents an economically and ecologically optimized process for the circular recovery and reuse of rare earth metals from diluted industrial wastewater from the mining, electronic, and chemical-catalyst producing sectors,” said Brück.

    “This system is expected to become economically feasible in the near future, as the demand and market prizes for REEs are likely to rise significantly in the coming years,” he predicted.

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    For editors / news media:

    Please link to the open access original research article “Rare earths stick to rare cyanobacteria: future potential for bioremediation and recovery of rare earth elements” in Frontiers in Bioengineering and Biotechnology in your reporting: https://www.frontiersin.org/articles/10.3389/fbioe.2023.1130939/full

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    Frontiers

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  • Microcalcification ‘fingerprints’ can yield info about cancer

    Microcalcification ‘fingerprints’ can yield info about cancer

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    Newswise — ITHACA, N.Y. — An interdisciplinary collaboration 10 years in the making used a materials science approach to “fingerprint” the calcium mineral deposits known as microcalcifications that reveal pathological clues to the progression of breast cancer and potentially other diseases.

    The group’s paper, “Biomineralogical Signatures of Breast Microcalcifications,” published Feb. 22 in Science Advances. The lead author is postdoctoral researcher Jennie Kunitake, Ph.D. ’21.

    Healthy mineral deposition is a delicately orchestrated process, as seen in bone and tooth formation. Sometimes, however, mineral deposits form in places they don’t belong, such as kidneys – i.e., kidney stones – and breast tissue. In the context of breast cancer, microcalcifications are a critical screening tool because they appear as vivid white specks in mammograms and, in certain cases, indicate the presence of breast cancer.

    “Usually after the initial mammogram, microcalcifications are largely ignored. And what we’re saying is we can look beyond the resolution of the mammogram, at the microscopic and chemical level, and get more information from these microcalcifications,” said co-senior author Lara Estroff, professor of materials science and engineering in Cornell Engineering. “By taking well-established, high-resolution characterization techniques from materials science and coupling those with an appreciation for biomineralization and how organisms can control the deposition of mineral, we’ve gained a unique insight into a pathological mineral that may have important implications for disease.”

    Estroff’s group specializes in biomineralization, i.e., how biological organisms control the growth of crystals in their tissues. More than a decade ago, she began collaborating with Claudia Fischbach, the Stanley Bryer 1946 Professor of Biomedical Engineering and a co-senior author of the paper, to explore the metastatic spread of breast cancer to bone. This led to an exploration of a “bizarre” phenomenon in which bone-like mineral appeared at primary tumor sites, and from there the collaborators became interested in the ways these microcalcifications can capture elements of the tissue microenvironment where they form, almost like a snapshot. The microenvironment, also known as the organic matrix, can in turn influence the mineral’s composition, morphologies and mechanical properties.

    “Minerals have different rules than biology,” Kunitake said. “Minerals forming in breast cancer could be trapping chemical information that reflect their formation environment, and that could potentially have clinical value and relevance.”

    While some cancer biologists have studied microcalcifications, the phenomenon has not been explored by materials scientists.

    “Biomineralization is a rather niche area that involves contributions from materials science, geology, biology and more. It’s very multidisciplinary,” Estroff said. “There’s absolutely no reason that oncologists would pay attention to the materials properties of these tiny little crystals that are appearing. I think it really took someone who had an idea of what the mineral could be offering to do this. We said, can we take everything that we know from studying physiological biominerals, and apply it now to these pathological minerals?”

    Fischbach connected Estroff and Kunitake with researchers at Memorial Sloan Kettering Cancer Center, who provided tissue samples containing microcalcifications from 40 breast cancer patients.

    Kunitake then began the arduous, years-long process of trying to understand exactly what they were looking at. She turned to Dr. Daniel Sudilovsky, then at Cayuga Medical Center, who helped characterize the pathology of each type of microcalcification they found.

    Next, rather than grind up and homogenize the tissue samples, as other studies had done, the researchers sought to obtain high-resolution, three-dimensional maps of the chemistry of the mineral and the organic matrix, such that they wouldn’t alter the tissue structure. So they collaborated with Admir Masic of Massachusetts Institute of Technology, a co-senior author of the paper, who used a vibrational spectroscopy technique called Raman microscopy that can detect the distinct vibrational signatures of a biological molecule’s organic and inorganic chemistries, and also map where those signatures are occurring.

    Kunitake then set about integrating and parsing all the data using techniques that were inspired by omics research in biochemistry and genetics.

    “One way to look at data, when you have a lot of it, is to use strategies from the omics communities,” Kunitake said. “It doesn’t have to be quantitative, just to visualize how the data behaves. Using hierarchical clustering, we could look at our data as a heatmap, and that gave us an idea of how different parameters that we measured were related to one another, and how the different calcifications grouped based on their fingerprints.”

    Among the researchers’ key findings: cancer-associated microcalcifications cluster into physiologically relevant groups that reflect the tissue type and local malignancy; mineral carbonate exhibits substantial variety inside the tumor; trace metals – including zinc, iron and aluminum – are enhanced in malignant-localized calcifications; and the ratio of lipids to proteins within microcalcifications is lower in patients with poor prognosis.

    While the researchers are not sure if the microcalcifications form before the cancer develops or because of it, the findings indicate there is a correlation with disease severity. The researchers are hopeful the findings may also illuminate calcifications in other types of cancer, such as thyroid and ovarian cancer.

    The team now plans to study a larger spread of disease characteristics, and also apply their approach to other pathological mineralization diseases, such as calcific aortic valve disease, in which mineral forms in the heart valve, or as Estroff says, “the mineral is the disease.”

    Co-authors include: Lynn Johnson, director and statistical consultant of the Cornell Statistical Consulting Unit; postdoctoral researcher Siyoung Choi; Dr. Daniel Sudilovsky of Kingman Regional Medical Center in Kingman, Arizona; Dr. Neil Iyengar, a medical oncologist in the Breast Medicine Service at Memorial Sloan Kettering Cancer Center and associate professor of medicine at Weill Cornell Medicine; and researchers from Memorial Sloan Kettering Cancer Center and MIT.

    The research was supported by the Human Frontier Science Program and by the National Cancer Institute’s Center on the Physics of Cancer Metabolism.

    The researchers made use of the Cornell Center for Materials Research, which is supported by the National Science Foundation’s MRSEC program, and the College of Veterinary Medicine’s Animal Health Diagnostic Center.

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    Cornell University

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  • SLAC, Stanford researchers make a new type of quantum material with a dramatic distortion pattern

    SLAC, Stanford researchers make a new type of quantum material with a dramatic distortion pattern

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    Newswise — Researchers at the Department of Energy’s SLAC National Accelerator Laboratory and Stanford University have created a new type of quantum material whose atomic scaffolding, or lattice,  has been dramatically warped into a herringbone pattern.

    The resulting distortions are “huge” compared to those achieved in other materials, said Woo Jin Kim, a postdoctoral researcher at the Stanford Institute for Materials and Energy Sciences (SIMES) at SLAC who led the study. 

    “This is a very fundamental result, so it’s hard to make predictions about what may or may not come out of it, but the possibilities are exciting,” said SLAC/Stanford Professor and SIMES Director Harold Hwang. 

    “Based on theoretical modeling from members of our team, it looks like the new material has intriguing magnetic, orbital and charge order properties that we plan to investigate further,” he said. Those are some of the very properties that scientists think give quantum materials their surprising characteristics. 

    The research team described their work in a paper published in Nature today.

    High-rises versus octahedrons

    The herringbone-patterned material is the first demonstration of something called the Jahn-Teller (JT) effect in a layered material with a flat, planar lattice, like a high-rise building with evenly spaced floors.  

    The JT effect addresses the dilemma an electron faces when it approaches an ion – an atom that’s missing one or more electrons. 

    Just like a ball rolling along the ground will stop and settle in a low spot, the electron will seek out and occupy the vacancy in the atom’s electron orbitals that has the lowest energy state. But sometimes there are two vacancies with equally low energies. What then? 

    If the ion is in a molecule or embedded in a crystal, the JT effect distorts the surrounding atomic lattice in a way that leaves only one vacancy at the lowest energy state, solving the electron’s problem, Hwang said. 

    And when the whole crystal lattice consists of JT ions, in some cases the overall crystal structure warps, so the electron’s dilemma is cooperatively solved for all the ions. 

    That’s what happened in this study.

    “The Jahn-Teller effect creates strong interactions between the electrons and between the electrons and the lattice,” Hwang said. “This is thought to play key roles in the physics of a number of quantum materials.” 

    The JT effect had already been demonstrated for single molecules and for 3D crystalline materials that consist of ions arranged in octahedral or tetrahedral structures. In fact, JT oxides based on manganese or copper exhibit colossal magnetoresistance and high-temperature superconductivity – leading scientists to wonder what would happen in materials based on other elements or having a different structure.

    In this study, the SIMES researchers turned a material made of cobalt, calcium and oxygen (CaCoO2.5), which has a different stacking of octahedral and tetrahedral layers and is known as brownmillerite,  into a layered material (CaCoO2) where the JT effect could take hold. They did it with a chemical trick developed at SIMES a few years ago to make the superconductivity-nickel-oxide-material”>first nickel oxide superconductor.

    Pulling out Jenga blocks

    Kim synthesized a thin film of brownmillerite and chemically removed single layers of oxygen atoms from its lattice, much like players carefully remove blocks from a Jenga tower. The lattice collapsed and settled into a flat, planar configuration with alternating layers containing negatively charged cobalt ions ­– the JT ions ­– and positively charged calcium ions. 

    Each cobalt ion tried to pull calcium ions from the layers above and below it, Kim said. 

    “This tug-of-war between adjacent layers led to a beautiful pattern of distortions that reflects the best and most harmonious compromise between the forces at play,” he said. “And the resulting lattice distortions are huge compared to those in other materials ­– equal to 25% of the distance between ions in the lattice.”

    Hwang said the research team will be exploring this remarkable new electronic configuration with X-ray tools available at SLAC and elsewhere. “We also wonder what will happen if we can dope this material – replacing some atoms with others to change the number of electrons that are free to move around,” he said. “There are many exciting possibilities.”

    Researchers from Cornell University, the Pohang Accelerator Laboratory in South Korea and the Center for Nanoscale Materials Sciences, a DOE Office of Science user facility at Oak Ridge National Laboratory, contributed to this work. It received major funding from the DOE Office of Science and the Gordon and Betty Moore Foundation’s Emergent Phenomena in Quantum Systems Initiative. 

     

    SLAC is a vibrant multiprogram laboratory that explores how the universe works at the biggest, smallest and fastest scales and invents powerful tools used by scientists around the globe. With research spanning particle physics, astrophysics and cosmology, materials, chemistry, bio- and energy sciences and scientific computing, we help solve real-world problems and advance the interests of the nation.

    SLAC is operated by Stanford University for the U.S. Department of Energy’s Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time.

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    SLAC National Accelerator Laboratory

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  • Physicists solve durability issue in next-generation solar cells

    Physicists solve durability issue in next-generation solar cells

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    Newswise — Physicists in the U.S. jumped a major hurdle standing in the way of the commercialization of solar cells created with halide perovskites as a lower-cost, higher-efficiency replacement for silicon when generating electricity from the sun.

    Published in the journal Science, the clean energy research led by The University of Toledo in collaboration with the University of Washington, University of Toronto, Northwestern University and Swiss Federal Laboratories for Materials Science and Technology solved the problem with the durability of perovskite solar cells, taking the technology one step closer to powering solar panels in the consumer market.

    “Perovskite solar cells offer a route to lowering the cost of solar electricity given their high power conversion efficiencies and low manufacturing cost,” said Dr. Yanfa Yan, UToledo Distinguished University Professor of physics and a member of the UToledo Wright Center for Photovoltaics Innovation and Commercialization. “However, we needed to strengthen the emerging solar cell technology’s endurance during outdoor operation.”

    The technology needs to survive for decades outdoors in all kinds of weather and temperatures without corroding or breaking down.

    “This challenge is no longer a roadblock to deploying the potential of perovskite solar cells,” Yan said. “Our breakthrough work improved device stability and presents ways of achieving success after a decade of research and development.”

    The team discovered the ingredient that enhances adhesion and mechanical toughness.

    Researchers experimentally demonstrated that perovskite solar cells treated with 1,3-bis(diphenylphosphino)propane (DPPP), a diphosphine Lewis base molecule, retained a high power conversion efficiency and exhibited superior durability after continuous operation under simulated sun illumination for more than 3,500 hours, or more than 145 days.

    They used what is called one sun illumination, which is equivalent to outdoor sunlight.

    “Phosphine-containing Lewis base molecules with two electron-donating atoms have a strong binding with the perovskite surface,” Yan said. “We saw the robust beneficial effects on perovskite film quality and device performance when we treated the perovskite solar cells with DPPP.”

    “DPPP is also a commercialized product with low cost and easy accessibility, which make it suitable for the commercialization of perovskite solar cells,” said Dr. Zhaoning Song, a research assistant professor in Yan’s lab at UToledo and one of the authors on the new paper.

    Researchers say the next step to move the technology forward is to employ their findings to make perovskite panels stable.

    Dr. Chongwen Li, the first author of the study and a UToledo alumnus, worked with Yan as a graduate student. Li earned his Ph.D. in physics from UToledo in 2020. He is a postdoctoral researcher at the University of Toronto.

    “Continuing to exploit the potentiality in the stability of perovskite solar cells is a crucial priority for the ongoing decarbonization of the world’s economy,” Li said. “After the successful demonstration of DPPP on improving the stability of perovskite solar cells, we are further applying it to large area perovskite solar panels and moving the prototype device forward to commercialization.”

    UToledo has been a trailblazer in solar energy research and development for more than 30 years.

    It has been a decade since Yan’s team at UToledo identified the ideal properties of perovskites, compound materials with a special crystal structure formed through chemistry, and started to focus their efforts on bringing together two different solar cells to increase the total electrical power generated by using two different parts of the sun’s spectrum.

    In November, a team of scientists from UToledo, the University of Toronto and Northwestern University collaborated to create an all-perovskite tandem solar cell with record-setting voltage. The research was published in the journal Nature.

    “Northwest Ohio is a global leader in solar technology, and The University of Toledo has been at the forefront of breakthrough after breakthrough. Investment and collaboration between the Department of Energy and world-class research professionals at our universities continues to pay dividends, as working men and women benefit from a growing solar industry,” said Congresswoman Marcy Kaptur (OH-09), ranking member of the House Appropriations Subcommittee on Energy and Water Development. “As a leading member on Energy and Water Development, I’ll continue to champion smart investment to power American energy independence.”

    The Wright Center for Photovoltaics Innovation and Commercialization was created at UToledo in 2007 to support solar energy research and manufacturing with $18.6 million in support from the Ohio Department of Development, along with matching contributions of $30 million from federal agencies, universities and industrial partners.

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  • Heralding the era of ‘Cost-effective Electric Car’

    Heralding the era of ‘Cost-effective Electric Car’

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    Newswise — Currently, most cathode materials used in batteries for electric vehicles are layered oxides composed of nickel for over 60% of the transition metals. Using nickel-rich layered oxide is advantageous in securing the mileage of an electric vehicle due to its high energy density, but its usage is limited by instability in the supply and demand of nickel raw materials. As an alternative, researchers focused on spinel cathode materials that use manganese as the main element, considering manganese is traded at a price of about 1/17 of nickel in the international spot market; however, the rapid decline in lifespan was an obstacle to commercialization.

    The Korea Institute of Science and Technology (KIST, President Seok Jin Yoon) announced that Dr. Jihyun Hong’s research team at the Energy Materials Research Center identified the cause of the rapid decline in life span-a chronic problem of high-capacity manganese-based spinel cathode materials. This team worked on significantly increasing the possibility of commercializing lithium batteries with manganese cathode materials as next-generation electric vehicle batteries.

    Manganese-based spinel cathode materials can theoretically store energy with a high density comparable to nickel-based commercial cathode materials. Considering the price of metal raw materials, the energy density per price for manganese-based spinel cathode could reach 2.8 times that of nickel-based cathodes. However, when using the battery at full capacity, a rapid decrease in lifespan is observed; as a result, practically only approximately 75% of the theoretical value could be stored. It has been established that the trivalent manganese (Mn3+) formed during the charging and discharging process of manganese-based spinel cathode materials distorts the crystal structure of the material, leading to the elution of manganese into the electrolyte and eventually causing a reduction in the lifespan of the cathode material. As a result, most research has focused on suppressing the formation of trivalent manganese.

    Contrary to mainstream academic theories, Dr. Hong’s team at KIST (first author: student researcher Gukhyun Lim) recently discovered that cathode materials exhibit excellent lifespan characteristics even when trivalent manganese is formed if the operating voltage range of the battery is adjusted. The research team utilized advanced material characterization techniques, including synchrotron radiation techniques, to interpret the phenomena that existing theories cannot explain. Through the thorough analyses, for the first time, it was identified that the side reaction at the interface between the cathode material and electrolyte during the repeated charging and discharging process is the cause of lifespan reduction.

    The research team further presented a key strategy to dramatically improve the lifespan of manganese-based materials by stabilizing the cathode-electrolyte interface. As an example of this strategy, introducing an EC-free electrolyte resulted in a 62% improvement in lifespan compared to commercial electrolytes. This improvement results in the highest capacity retention and rate capability among the performances of manganese-based spinel cathode materials simultaneously using nickel and manganese redox reactions reported so far.

    Dr. Hong of KIST said, “Through this research, KIST presented a new methodology for commercializing manganese-based high-energy cathode materials, which will be a catalyst for the expansion of electric vehicles.” He also mentioned, “If academia and industry focus on applying the interface stabilization technology of nickel-based cathode materials, which has accumulated a lot of capabilities, to manganese-based next-generation cathode materials, we expect that Korean companies in the automobile industry could maintain a higher level of competitiveness in the future.”

    ###

    KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/

    This research was conducted under major KIST projects and Individual Research program (excellent young researcher, mid-career researcher) of the National Research Foundation of Korea with the support of the Ministry of Science and ICT (Minister Jong-ho Lee), with the research results selected as the full front cover page paper of ‘Advanced Energy Materials’ (IF: 29.698, top 2.464% in the JCR field), a world-renowned journal in the field of energy materials.부수적 정보 기술

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    National Research Council of Science and Technology

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  • New Sodium, Aluminum Battery Aims to Integrate Renewables for Grid Resiliency

    New Sodium, Aluminum Battery Aims to Integrate Renewables for Grid Resiliency

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    Newswise — RICHLAND, Wash.—A new battery design could help ease integration of renewable energy into the nation’s electrical grid at lower cost, using Earth-abundant metals, according to a study just published in Energy Storage Materials. A research team, led by the Department of Energy’s Pacific Northwest National Laboratory, demonstrated that the new design for a grid energy storage battery built with the low-cost metals sodium and aluminum provides a pathway towards a safer and more scalable stationary energy storage system.

    “We showed that this new molten salt battery design has the potential to charge and discharge much faster than other conventional high-temperature sodium batteries, operate at a lower temperature, and maintain an excellent energy storage capacity,” said Guosheng Li, a materials scientist at PNNL and the principal investigator of the research. “We are getting similar performance with this new sodium-based chemistry at over 100 °C [212 °F] lower temperatures than commercially available high-temperature sodium battery technologies, while using a more Earth-abundant material.”

    More energy storage delivered

    Imre Gyuk, director of DOE’s Office of Electricity, Energy Storage Program, which supported this research, noted “This battery technology, which is built with low-cost domestically available materials brings us one step closer toward meeting our nation’s clean energy goals.”

    The new sodium-based molten salt battery uses two distinct reactions. The team previously reported a neutral molten salt reaction. The new discovery shows that this neutral molten salt can undergo a further reaction into an acidic molten salt. Crucially, this second acidic reaction mechanism increases the battery’s capacity. Specifically, after 345 charge/discharge cycles at high current, this acidic reaction mechanism retained 82.8 percent of peak charge capacity.

    The energy that a battery can deliver in the discharge process is called its specific energy density, which is expressed as “watt hour per kilogram” (Wh/kg). Although the battery is in early-stage or  “coin cell” testing, the researchers speculate that it could result in a practical energy density of up to 100 Wh/kg. In comparison, the energy density for lithium-ion batteries used in commercial electronics and electric vehicles is around 170–250 Wh/kg. However, the new sodium-aluminum battery design has the advantage of being inexpensive and easy to produce in the United States from much more abundant materials.

    “With optimization, we expect the specific energy density and the life cycle could reach even higher and longer,” added Li.

    Sodium battery shows its mettle

    Indeed, PNNL scientists collaborated with colleagues at the U.S.-based renewable energy pioneer Nexceris to assemble and test the battery. Nexceris, through their new business Adena Power, supplied their patented solid-state, sodium-based electrolyte to PNNL to test the battery’s performance. This crucial battery component allows the sodium ions to travel from the negative (anode) to the positive (cathode) side of the battery as it charges.

    “Our primary goal for this technology is to enable low-cost, daily shifting of solar energy into the electrical grid over a 10- to 24-hour period,” said Vince Sprenkle, a PNNL battery technology expert with more than 30 patented designs for energy storage systems and associated technology. “This is a sweet spot where we can start to think about integrating higher levels of renewables into the electrical grid to provide true grid resiliency from renewable resources such as wind and solar power.”

    Sprenkle was part of the team that developed this battery’s new flexible design, which also shifted the battery from a traditional tubular shape to a flat, scalable one that can more easily be stacked and expanded as the technology develops from coin-sized batteries to a larger grid-scale demonstration size. More importantly, this flat cell design allows the cell capacity to be increased by simply using a thicker cathode, which the researchers leveraged in this work to demonstrate a triple capacity cell with sustained discharge of 28.2-hours under laboratory conditions.

    Most current battery technologies, including lithium-ion batteries, are well suited for short-term energy storage. To meet the demand for 10-plus hours of energy storage will require the development of new, low-cost, safe, and long duration battery concepts beyond current state-of-the-art battery technologies. This research provides a promising lab-scale demonstration toward that goal.

    Variation on a grid resilience theme

    The ability to store energy generated by renewable energy and release it on demand to the electrical grid has driven rapid advances in battery technology, with many new designs competing for attention and customers. Each new variation must satisfy the demands of its own niche use. Some batteries, such as those having PNNL’s freeze-thaw battery design, are capable of storing energy generated seasonally for months at a time.

    Compared with a seasonal battery, this new design is especially adept at short- to medium-term grid energy storage over 12 to 24 hours. It is a variation of what’s called a sodium-metal halide battery. A similar design employing a nickel cathode as part of the system has been shown effective at commercial scale and is already commercially available.

    “We have eliminated the need for nickel, a relatively scarce and expensive element, without sacrificing battery performance,” said Li. “Another advantage of using aluminum over nickel is that the aluminum cathode charges more quickly, which is crucial to enable the longer discharge duration demonstrated in this work.”

    With this milestone reached, the team is focusing on further improvements to increase the discharge duration, which could greatly improve grid flexibility for greater incorporation of renewable power sources.

    And because it operates at a lower temperature, it can be manufactured with inexpensive battery materials, instead of requiring more complex and expensive components and processes as in conventional high-temperature sodium batteries, said David Reed, a PNNL battery expert and study co-author.

    More grid energy storage at lower cost

    In 2023, the state-of-the-art for grid energy storage using lithium-ion batteries is about four hours of energy storage capacity, said Sprenkle. “This new system could significantly increase the amount of stored energy capacity if we can reach the expected cost targets for materials and manufacturing,” he added.

    As part of the study, the researchers estimated that a sodium-aluminum battery design based on inexpensive raw materials could cost just $7.02 per kWh for the active materials. Through optimization and increasing the practical energy density, they project that this cost could be lowered even further. This promising low-cost, grid-scale storage technology could enable intermittent renewables like wind and solar power to contribute more dynamically to the nation’s electrical grid.

    Neil Kidner, a study co-author and president of Adena Power, a sodium solid-state battery manufacturer, is collaborating with PNNL to advance sodium-based battery technology. “This research demonstrates that our sodium electrolyte works not only with our patented technology but also with a sodium-aluminum battery design,” he said. “We look forward to continuing our partnership with the PNNL research team towards advancing sodium battery technology.”

    The research was supported by the DOE Office of Electricity and the International Collaborative Energy Technology R&D Program of the Korea Institute of Energy Technology Evaluation and Planning. The electrolyte development was supported by a DOE Small Business Innovation Research program. The nuclear magnetic resonance measurements were made in EMSL, Environmental Molecular Sciences Laboratory, a DOE Office of Science User Facility sponsored by the Biological and Environmental Research program.

    Learn more about PNNL’s grid modernization research, and the Grid Storage Launchpad, opening in 2024.

    ​About PNNL

    Pacific Northwest National Laboratory draws on its distinguishing strengths in chemistry, Earth sciences, biology and data science to advance scientific knowledge and address challenges in sustainable energy and national security. Founded in 1965, PNNL is operated by Battelle for the Department of Energy’s Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States. DOE’s Office of Science is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science. For more information on PNNL, visit PNNL’s News Center. Follow us on Twitter, Facebook, LinkedIn and Instagram.

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  • A quasiparticle that can transfer heat under electrical control

    A quasiparticle that can transfer heat under electrical control

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    Newswise — COLUMBUS, Ohio – Scientists have found the secret behind a property of solid materials known as ferroelectrics, showing that quasiparticles moving in wave-like patterns among vibrating atoms carry enough heat to turn the material into a thermal switch when an electrical field is applied externally.

    A key finding of the study is that this control of thermal conductivity is attributable to the structure of the material rather than any random collisions among atoms. Specifically, the researchers describe quasiparticles called ferrons whose polarization changes as they “wiggle” in between vibrating atoms – and it’s that ordered wiggling and polarization, receptive to the externally applied electrical field, that dictates the material’s ability to transfer the heat at a different rate. 

    “We figured out that this change in position of these atoms, and the change of the nature of the vibrations, must carry heat, and therefore the external field which changes this vibration must affect the thermal conductivity,” said senior author Joseph Heremans, professor of mechanical and aerospace engineering, materials science and engineering, and physics at The Ohio State University.  

    “People tend to think atom vibrations are a given fact and don’t respond to an electric field or a magnetic field. And we are saying you can affect them with an electric field.” 

    With the use of a simple external electrical stimulus, the thermal conductivity in this type of material can be changed at room temperature rather than at the extremely low temperatures required to control most candidate materials for solid-state heat switches, enhancing the possibilities for real-world applications of the technology, the researchers say. 

    The study is published Feb. 1, 2023, in the journal Science Advances. 

    The material used in the study is a common lead zirconium titanate ceramic belonging to a class of materials called piezoelectrics, which change shape when an electric field is applied to them or produce an electrical charge under mechanical stress. 

    Ferroelectrics, a subset of piezoelectrics, are materials in which the electrical charges on the atoms can spontaneously form electrical dipoles that all align in the same direction, forming what is known as polarization. These dipoles can be switched by an external electric field.  

    Until now, scientists had not formally written down how this polarization will move when heat is applied. In this new article, this motion is described by introducing the quasiparticle – called a ferron – that carries waves of polarization and heat at the same time. The ferron is sensitive to an external electric field, and that means the application of an external electrical field can turn the material into a heat switch. 

    “The quasiparticle has always been there. It just hasn’t been identified and measured,” said first author Brandi Wooten, a PhD student in materials science and engineering at Ohio State. 

    Wooten likened ferrons’ behavior to a stadium wave, with each sports fan representing a cell of atoms collected together in a crystal. 

    “You have all these atoms, and they have this special dipole – an atom with an electrical charge that moves up and down creates a dipole. You can think of people’s hands going up doing the wave as the dipole’s strength – if their hands are up, it’s really strong. If they’re a little bit down, it’s weaker, and if they’re all the way down, it’s negative,” she said. “That’s the dipole’s strength. We found that these special waves carry both heat and polarization, and we labeled them ferrons.” 

    This heat-transferring property is induced by the electric field through a phenomenon known as the piezoelectric strain: The lattice contracts or stretches when the voltage is applied, with atoms and forces between them moving back and forth, ultimately changing the mechanical properties of the material and, as a result, changing its thermal conductivity, said Heremans, also an Ohio Eminent Scholar in Nanotechnology. 

    “The ferron is also sensitive to strain in the solid. Since the ferron carries heat, that makes the amount of heat carried dependent on the electrical field,” he said. “So we wrote a new theory that relates an external electric field, the strain it induces in a ferroelectric, and ultimately how this strain affects the thermal conductivity.” 

    The theory is predictive, so researchers can now use it to find materials where the effect is much larger, ultimately leading to materials where it is large enough to be used in heat switches in everyday applications, like collection of solar power. 

    The application of an electrical field to the material produced a 2% difference between maximum and minimum conductivity – as the new theory predicted would be the case. A series of experiments quantifying the atomic vibrations through measuring the velocity of the material’s sound waves and equilibrium and transport properties validated “that this all depends only on the material structure, not necessarily what’s scattering the vibrations,” Wooten said.

    The researchers are now studying other materials that might increase that change in thermal conductivity by up to 15%, as the new theory predicts. 

    “Any application depends on us finding a material where the effect is much larger,” Heremans said. “We are looking for materials that have the right parameters.”

    This work was supported by the National Science Foundation, the U.S. Department of Defense, the Japanese Society for the Promotion of Science and the Japanese Science and Technology Agency. 

    Additional co-authors include Ryo Iguchi and Ken-ichi Uchida of the National Institute for Materials Science in Japan; Ping Tang and Gerrit Bauer of Tohoku University; and Joon Sang Kang of Ohio State.

     

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  • Researchers: Energy-efficient construction materials work better in colder climates

    Researchers: Energy-efficient construction materials work better in colder climates

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    Newswise — The researchers from Lithuania and Cyprus claim that the energy payback period of using phase change materials, new technology in the construction industry, is the shortest in a colder climate. The optimal location for their usage is the interior on the northern side of the building. The study provides informed answers regarding the application of PCMs to improve buildings’ energy efficiency.

    In recent years, phase change materials (PCMs) used to improve the energy efficiency of buildings are gaining momentum. PCMs can store and release large amounts of energy – when in a solid phase, they can absorb heat, providing a cooling effect and when a PCM is in its liquid phase it can release heat, providing a warming effect.

    “The ice melting to water is a phase change material, as is butter melting to oil. Why is it special? When material changes phase, it also absorbs and releases energy. In construction, these materials are encapsulated, i.e. the micro PCM capsules are integrated into a building element, such as concrete,” explains Paris Fokaides, a principal investigator at Kaunas University of Technology (KTU), Lithuania.

    Together with colleagues from Frederick University in Cyprus, KTU researchers were conducting a study in different European regions aiming to calculate the efficiency of the application of PCMs for the energy upgrade of the existing buildings. Their research revealed that the efficiency and energy payback period of PCM depends on certain conditions, such as the geographical location and the wall orientation of the building.

    “The thermal performance assessment of existing buildings is highly valuable information, which can be useful when making renovation decisions,” says Eglė Klumbytė, a researcher at KTU Faculty of Civil Engineering and Architecture, a co-author of the study.

    According to her, it is important to understand how and where to use the appropriate materials for maximum efficiency.

    In cold climates, the investments pay off in less than a year

    The work examines the application of PCM coatings in diverse meteorological conditions in Europe, for all major buildings’ orientations. In total, 16 numerical simulations were carried out for the four calendar months of January, April, July and October and for three latitudes of Athens, Milan and Copenhagen.

    “We wanted our research results to be globally applicable, that’s why we chose the locations with typical climatic conditions in Southern, Central and Northern Europe,” says Fokaides.

    The first 8 numerical simulations were performed with phase change material integrated into the building element structure and the other 8 simulations – in the absence of PCM. The PCM thickness incorporated was 4 cm. The annual energy saving was calculated for four typical months, representing the four seasons of the year (winter, spring, summer, and autumn).

    “One of the main study outcomes highlighted the fact that PCM performed better under cold conditions,” says Klumbytė.

    According to the researchers, this makes perfect sense – firstly, in colder conditions, PCM absorbs more energy, and secondly, since in colder climates the buildings use more energy (electricity, heating, etc.) the energy saving in these conditions is more efficient.

    “In the study, we have developed the energy payback period concept, which means the balance between the energy used to produce these materials and gained while using them. Energy payback period indicates how long it will take for the energy that is saved in the PCMs to eliminate the energy costs of their production,” explains Fokaides.

    The study revealed that PCM implementation can contribute to energy savings in certain cases, varying from 0.24 up to 29,84 kWh/m2a and energy payback periods from less than a year to almost 20 years. The longest energy payback period was calculated in warmer climates, and the shortest – in colder locations. The optimal orientation for placing PCMs is west and east in Athens, east and north in Milan, and north in Copenhagen. Also, PCMs work best when they are integrated into interior structures.

    Researched topics never discussed before

    “The developed numerical model demonstrates the ability to carry out a thermal assessment under diverse conditions with accurate results. The main goal of the European Union is sustainable environmental development. Our study can greatly contribute towards achieving this goal,” Klumbytė is convinced.

    According to Fokaides, the above-described study is researching topics that have not been discussed in scientific literature before. The optimal location of the phase change material in the building, its optimal orientation and the energy payback period are entirely new concepts in the broad theme of the energy performance of the built environment.

    “However, being a Greek, I cannot overlook the fact that the first description of an eco-friendly building was written by Socrates 2.5 thousand years ago. Back then, he indicated that the northern wall of a building needs to be thicker compared to the southern, thus our idea that wall orientation is crucial when considering its structural composition is related to that of Socrates,” says a KTU researcher.

    The KTU researchers claim that the methodology and dataset provided in this work can be used for further development of the buildings’ thermal assessment tools. Currently, the team is starting a new 1.5 million worth research project, which will focus on the digitalisation of the findings. This could include developing smart sensors to measure building elements’ thermal performance in real-time and other aspects. According to scientists, this topic has vast potential for commercialisation.

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    Kaunas University of Technology

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  • With nanoeffects towards new joining processes

    With nanoeffects towards new joining processes

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    Newswise — Gordon Moore was right. In April 1965, the US engineer and later co-founder of Intel predicted that the number of transistors on a chip would double about every two years. To this day, this development continues with nearly the same speed – also because chip manufacturers worldwide use Moore’s Law as the basis for their strategic planning. Thus, the prophecy is self-fulfilling.

    But the doubling of the number of circuits every two to three years sometimes reaches the limits of what is technically feasible. This also holds for the joining technologies, which have to keep up with the increased demands. After all, the ever smaller and more powerful electronic components still have to be integrated into larger systems, and the joints connecting the components to heat sinks or circuit boards should not fall apart during temperature changes or vibrations, or overheat during operation. A team led by Jolanta Janczak-Rusch and Bastian Rheingans from Empa’s Laboratory for Joining Technologies and Corrosion is tackling this problem.

    Industry in need

    “Our partners and customers, for whom we develop customized solutions, always want more, and preferably everything at the same time,” says Janczak-Rusch. A joint for a new high-performance electronic component, for example, should be made at the lowest and gentlest possible temperature – and yet survive the highest possible temperatures when the component is in operation, and efficiently dissipate waste heat from the components. This is the only way to combine miniaturization and increased performance without at the same time increasing the cost of cooling to infinity. Other advancing technologies such as photonics, sensor technology, space travel, batteries and turbine construction are also dependent on innovative joining concepts.

    New materials and processes are therefore needed to meet the increasingly complex demands placed on joining. In this situation, joining with nanomaterials, so-called nanojoining, offers great potential. Industry is already using silver nanopastes, i.e. joining materials consisting of silver nanoparticles. The advantage: While the melting point for pure silver is 962 degrees Celsius, silver nanopastes can be applied to produce electrically and thermally highly conductive joints at temperatures as low as 250 degrees Celsius. And even better: Once produced, these joints can even withstand an operating temperature above their production temperature.

    Utilizing nanoeffects

    There’s a lot of materials science know-how behind this innovative solution. “Here we are replacing a classic soldering process with a sintering process,” explains Rheingans. This means that the particles in the joining zone are not melted, but grow together into larger particles and grains by diffusion, thereby reducing their surface energy. Diffusion, i.e. the movement of individual atoms, is very rapid at surfaces and interfaces. Since nanoparticles have an extremely large surface area in relation to their volume, sintering is particularly pronounced on the nanoscale and can be exploited even at comparatively low temperatures. In the case of very small nanoparticles or thin nanolayers, the amount of easily moving, “liquid” surface atoms becomes so large that the melting point can drop several hundred degrees below the melting point of the solid material. The researchers call this effect MPD (Melting Point Depression) – and use it to develop innovative and efficient joining processes.

    The race continues

    “We are working on nanopastes with multiple components to optimize the properties of the joining compound and to open up new areas of application,” Rheingans says. “For example, we are investigating combinations of copper and nickel nanopastes.” These metals are less expensive than silver and exhibit very interesting electrical and thermal properties – but because they are less noble metals, they oxidize much more easily. That has to be prevented in the joining process. “So we put the nanoparticles in a paste of organic adjuvants that evaporate during the joining process and reduce the oxide on the particle surface. Or we coat the particles with a protective coating,” explains the Empa researcher. Using special analytical methods such as X-ray diffraction (XRD) or X-ray photoelectron spectroscopy (XPS), the researchers can verify whether the postulated method of protecting the nanoparticles works as intended.

    But innovation is also possible with the well-known silver nanopaste: “In an Empa research project for the development of oxide membranes for microelectronics, we were able to effectively support our colleagues with our know-how: using the nanopaste, we could transfer the ultra-thin membranes onto a carrier substrate without introducing any damage,” says Rheingans. This method could also be applied to other 2D materials.

    An oven on the nanoscale

    For particularly temperature-sensitive components, the researchers have another nanojoining method that they are continuously developing further: so-called reactive joining. In this process, reactive foils replace the soldering oven as a local source of heat. The foils consist of a large number of individual nanolayers, for example of nickel or aluminum. When these nano-multilayers are ignited, the nickel and aluminum react and form a new chemical compound – and release a great deal of heat that drives the process and makes it travel at speeds of up to 50 meters per second over the entire foil. Only layer thicknesses in the nano-range enable such a fast and self-perpetuating reaction. Locally, temperatures of up to 1000 degrees Celsius can be reached, but because of the low thickness of the reactive foil, the total amount of heat remains small and limited to the adjacent solder layers. In this way, sensitive electronic elements can be gently and firmly attached to copper heat sinks.

    Nanolayer systems to combat heat buildup

    An important focus in recent years has been the development of nanomultilayer systems starting from classic brazing filler metal/alloys such as copper, silver, silver-copper or aluminum-silicon: “Due to the lowering of the melting point and the rapid diffusion on the nanoscale, these  bonding materials offer the possibility of carrying out joining processes much faster and at significantly lower temperatures than with conventional brazing techniques” explains Janczak-Rusch.
    Nanomultilayers can also be used elsewhere in the joining process: With the recently approved SNF-NCN Lead Agency project “Development of submicro- and nanostructured Cu-Mo composites with tailored properties for thermal management,” the Advanced Joining Technologies team is addressing the burning issue of heat dissipation in miniaturized electronic components.

    “The interesting properties of copper-molybdenum composites have already been used in the design of an ion source for the JUICE mission of the European Space Agency ESA,” says Empa researcher Hans Rudolf Elsener, who specializes in space missions. Together with Polish researchers, the potential of nanostructured Cu-Mo multilayer systems as heat sinks will now be specifically investigated and suitable joining processes for their integration will be developed.

    Glossary Joining techniques

    Soldering/Brazing: The base materials are joined together by melting an additional material, the solder/brazing filler alloy. The workpieces themselves are not melted or fused during the process. Up to 450 degrees Celsius, this is referred to as soldering, and above 450 degrees as brazing.

    Welding: In contrast to brazing, the workpieces are partially melted and are immediately joined after cooling. Filler materials are often introduced into the weld seam to increase the amount of molten metal.

    Nanojoining is a new scientific discipline. It includes joining techniques for joining nano-objects, but also novel, high-performance joining processes that utilize nano-effects. Empa is one of the main players in this new discipline, as well as a founding member and headquarters of the international Nano- & Microjoining Association.

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  • Development of 100% Biodegradable Paper Straws that Do Not Become Soggy

    Development of 100% Biodegradable Paper Straws that Do Not Become Soggy

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    Newswise — Eco-friendly paper straws that do not easily become soggy and are 100% biodegradable in the ocean and soil have been developed. The straws are easy to mass-produce and thus are expected to be implemented in response to the regulations on plastic straws in restaurants and cafés.

    The paper straws that are currently available are not entirely made of paper alone. Straws made with 100% paper become too soggy when they come in contact with liquids and cannot function as straws. Accordingly, their surface should be coated. The most commonly used coating materials for paper straws are polyethylene (PE) or acrylic resin—the same materials used for making plastic bags and adhesives. Paper cups are also coated with the same materials as paper straws. A large number of previous studies have reported that polyethylene coating on discarded paper cups can disintegrate into small particles without being fully decomposed and become microplastics. Moreover, these paper products are made with paper and plastics (two very different materials) and thus it is difficult to recycle them.

    Conventional paper straws are inconvenient to use. Upon prolonged contact with a liquid, they become soggy. Also, when these straws are used to drink carbonated beverages, many bubbles may form owing to their surface properties. Currently, polylactic acid (PLA) straws and rice straws are available in the market as alternatives to paper straws. However, PLA straws—also known as corn plastic straws—do not decompose well in the ocean. While rice straws decompose well in the environment, they have disadvantages, including higher prices, due to difficulties in their mass-production and their sharp cross-sections.

    The joint research team of Dr. Oh Dongyeop and Dr. Kwak Hojung of KRICT and Professor Park Jeyoung of Sogang University have developed eco-friendly paper straws that are 100% biodegradable, perform better than conventional paper straws, and can be easily mass-produced.

    Using their technology, the research team synthesized a well-known biodegradable plastic, polybutylene succinate (PBS)*, by adding a small amount of cellulose nanocrystals to create a coating material. The added cellulose nanocrystals are the same material as the main component of paper, and this allows the biodegradable plastic to firmly attach to the paper surface during the coating process.

    * PBS (polybutylene succinate): Polyester-based biodegradable bioplastic with similar properties to those of petroleum-based polypropylene.

    Conventional paper straws do not incorporate a material that will strongly attach the plastic coating to the surface of the straws. The surface of the straws thus is not uniformly coated with plastic, impeding their use. The most significant limitations this creates are that the straws become soggy when a liquid touches the uncoated part and bubbles extensively form when paper straws are left in carbonated beverages. This is because the uncoated part easily combines with water, whereas the coated plastic part has the property of repelling water, causing the carbonated drink to contact the uneven surface of the paper straws.

    These limitations are overcome by the new paper straws developed by our research team; they do not become soggy easily or cause bubble formation in carbonated drinks because the coating material uniformly and strongly covers the surface of the straws. Also, the coating material is made of paper and biodegradable plastic and therefore will decompose and degrade completely.

    The research team found that these eco-friendly paper straws maintain their physical integrity in not only cold drinks but also hot drinks. The team also found that the straws did not become soggy when used to stir various beverages such as water, tea, carbonated drinks, milk, and other drinks containing lipids, or upon prolonged contact with liquids. The degree of sogginess of the as-prepared paper straws and conventional paper straws was compared. The conventional paper straw was severely bent when a weight of approximately 25g was suspended after the straw was dipped in cold water at 5°C for 1 min. In contrast, the as-prepared paper straw did not bend as much even when the weight was more than 50g under the same conditions.

    The newly developed straws decompose well, even in the ocean. In general, paper or plastic decomposes much more slowly in the ocean than in soil because of the ocean’s low temperature and high salinity, which impede growth of microbes. The research team performed a decomposition test in a marine environment by immersing the straw samples at a depth of 1.5–2 m on the coast near Pohang, South Korea.

    Regular plastic straws and corn plastic straws did not decompose after 120 days. Conventional paper straws preserved their shape and lost only 5% of their total weight. In contrast, the straws developed by the research team lost more than 50% of their weight after 60 days and decomposed completely after 120 days.

    “This technology is but a small step toward the direction we need to take in this era of plastic. Turning a plastic straw we often use into a paper straw will not immediately impact our environment, but the difference will be profound over time. If we gradually change from using convenient disposable plastic products to various eco-friendly products, our future environment will be much safer than what we now worry about,” said the head researcher, Dr. Oh Dongyeop.

     

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    KRICT was established as a government-funded research institute in 1976. KRICT has played a leading role in the development of the national chemical industry as it developed technologies for chemical and related fields of convergence, transferred chemical technologies to industries, produced professionals in the chemical field, and provided tremendous support for a variety of chemical infrastructures. Now we promise to reach new heights in chemistry and chemical engineering and continue our role in facilitating increased use of the knowledge from research. For more information, please visit KRICT’s website at https://www.krict.re.kr/eng/

    This achievement was supported by the Nano·Material Technology Development Program through the Ministry of Science and ICT, the Basic Science Research Program through KRICT, and the Biodegradable Bioplastics Commercialization and Demonstration Project through the Ministry of Trade, Industry and Energy.

    The research results were published in the international academic journal Advanced Science (IF:17.52) under the title ‘Biodegradable, Water-resistant, Anti-fizzing, Polyester Nanocellulose Composite Paper Straws’ on November 21, 2022, and are accessible to the public.

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  • Meteorites reveal likely origin of Earth’s volatile chemicals

    Meteorites reveal likely origin of Earth’s volatile chemicals

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    Newswise — By analysing meteorites, Imperial researchers have uncovered the likely far-flung origin of Earth’s volatile chemicals, some of which form the building blocks of life. 

    They found that around half the Earth’s inventory of the volatile element zinc came from asteroids originating in the outer Solar System – the part beyond the asteroid belt that includes the planets Jupiter, Saturn, and Uranus. This material is also expected to have supplied other important volatiles such as water. 

    Volatiles are elements or compounds that change from solid or liquid state into vapour at relatively low temperatures. They include the six most common elements found in living organisms, as well as water. As such, the addition of this material will have been important for the emergence of life on Earth. 

    Prior to this, researchers thought that most of Earth’s volatiles came from asteroids that formed closer to the Earth. The findings reveal important clues about how Earth came to harbour the special conditions needed to sustain life. 

    Senior author Professor Mark Rehkämper, of Imperial College London’s Department of Earth Science and Engineering, said: “Our data show that about half of Earth’s zinc inventory was delivered by material from the outer Solar System, beyond the orbit of Jupiter. Based on current models of early Solar System development, this was completely unexpected.” 

    Previous research suggested that the Earth formed almost exclusively from inner Solar System material, which researchers inferred was the predominant source of Earth’s volatile chemicals. In contrast, the new findings suggest the outer Solar System played a bigger role than previously thought. 

    Professor Rehkämper added: “This contribution of outer Solar System material played a vital role in establishing the Earth’s inventory of volatile chemicals. It looks as though without the contribution of outer Solar System material, the Earth would have a much lower amount of volatiles than we know it today – making it drier and potentially unable to nourish and sustain life.” 

    The findings are published today in Science. 

    To carry out the study, the researchers examined 18 meteorites of varying origins – eleven from the inner Solar System, known as non-carbonaceous meteorites, and seven from the outer Solar System, known as carbonaceous meteorites.  

    For each meteorite they measured the relative abundances of the five different forms – or isotopes – of zinc. They then compared each isotopic fingerprint with Earth samples to estimate how much each of these materials contributed to the Earth’s zinc inventory. The results suggest that while the Earth only incorporated about ten per cent of its mass from carbonaceous bodies, this material supplied about half of Earth’s zinc. 

    The researchers say that material with a high concentration of zinc and other volatile constituents is also likely to be relatively abundant in water, giving clues about the origin of Earth’s water. 

    First author on the paper Rayssa Martins, PhD candidate at the Department of Earth Science and Engineering, said: “We’ve long known that some carbonaceous material was added to the Earth, but our findings suggest that this material played a key role in establishing our budget of volatile elements, some of which are essential for life to flourish.” 

    Next the researchers will analyse rocks from Mars, which harboured water 4.1 to 3 billion years ago before drying up, and the Moon. Professor Rehkämper said: “The widely held theory is that the Moon formed when a huge asteroid smashed into an embryonic Earth about 4.5 billion years ago. Analysing zinc isotopes in moon rocks will help us to test this hypothesis and determine whether the colliding asteroid played an important part in delivering volatiles, including water, to the Earth.” 

    This work was funded by the Science and Technology Facilities Council (STFC – part of UKRI) and Rayssa Martins is funded by an Imperial College London Presidents’ PhD Scholarship. 

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  • George Crabtree, energy trailblazer remembered as a ​“great listener” and ​“boundless explorer”, dead at 78

    George Crabtree, energy trailblazer remembered as a ​“great listener” and ​“boundless explorer”, dead at 78

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    Newswise — Distinguished researcher led Argonne’s Joint Center for Energy Storage Research and made pivotal discoveries in high-temperature superconductors.

    George Crabtree, widely recognized and admired as a brilliant, passionate materials scientist and champion of superconducting materials and better batteries, died Jan. 23. He was 78.

    As the director of the U.S. Department of Energy’s (DOE) Joint Center for Energy Storage Research (JCESR) and a preeminent proponent of decarbonization, Crabtree reached the pinnacle of a career that spanned parts of seven decades at DOE’s Argonne National Laboratory and that advanced a number of different disciplines and inspired colleagues and friends.

    “I never could have imagined when I first came to Argonne as an undergraduate student that one day I would be directing a big energy storage hub,” Crabtree said recently. ​“That was the farthest thing from my mind. Now I consider that to be one of my best experiences.”

    “As a scientist and a leader, George worked with true integrity and exemplified Argonne’s mission of engaging with some of the biggest challenges facing humanity,” said Argonne Director Paul Kearns. ​“His interest in science and genuine concern for others resulted in a leadership style that was empowering and motivating to generations of colleagues. George had the exceptional ability to bring people together to achieve impactful science for our country.”

    George Crabtree was born on Nov. 28, 1944, in Little Rock, Arkansas, and moved with his family to Illinois when he was 2.

    As a boy, Crabtree was ​“fascinated by the natural world and sought to understand it in all of its complexity,” said JCESR research integration leader Lynn Trahey, whom Crabtree mentored for the past ten years. ​“He told me that when he was young, he was just as interested in biology as physics — he was a boundless explorer.”

    Crabtree first joined Argonne as an intern in 1964 while a college student at Northwestern University. He was hired full-time in 1969 while pursuing his Ph.D. in condensed matter physics at the University of Illinois Chicago, where he took night classes while working.

    In the first part of his career in the last decades of the 20th century, Crabtree’s work focused on the behavior of superconducting materials, in particular their behavior in high magnetic fields. At the time, these materials were mysterious and not well understood, and their mystique held appeal for Crabtree. ​“For me, it was always a curiosity question,” he told the MRS Bulletin.

    Crabtree helped pioneer early research into high-temperature superconductors, which were discovered in 1986. In them, he discovered new phases of superconducting vortex matter. ​“The properties of vortices are important because they are responsible for all the electromagnetic behavior in high-temperature superconductors that could eventually make them useful for applications,” said Argonne materials scientist Ulrich Welp

    “George was a great leader because he had high standards; he elevated everyone around him because he really set an example for everyone else,” said Argonne materials scientist Wai-Kwong Kwok.

    “His leadership style was full of kindness and curiosity,” Trahey said. ​“He wanted to learn and explore and also have a positive impact on society — he was unlimited in what he wanted to learn if it could help him communicate challenges and inspire people.”

    Kwok recalled camping trips that Crabtree would organize for the other scientists in Argonne’s materials science division and their families. ​“He’d be the one up before everyone else making breakfast by the campfire,” he said. ​“In everything, he was truly an endearing person; he cared about more than just work, and his optimism and his hope would just rub off on you.”

    Crabtree’s work on superconductors gained him recognition as a member of the American Association for the Advancement of Science, the American Physical Society and the National Academy of Sciences. At Argonne, he was named a Distinguished Fellow. In 2003, Crabtree won the second ever Kammerlingh Onnes Prize, an international award given to scientists doing work in superconductivity.

    “George was always a great listener, he would listen to everyone’s input and come up with a solution everyone could agree upon,” Kwok said. ​“There would always be something for everyone.”

    In 2012, Crabtree switched gears professionally when he was named director of JCESR. ​“George was educating himself on battery science along with the postdocs and graduate students,” Trahey said. ​“He was never afraid to ask a question, and he treated 19-year-old students and heads of state with equal respect.”

    As director of JCESR, Crabtree oversaw experiments on a wide range of beyond lithium-ion battery chemistries, including redox flow batteries and multivalent batteries. ​“In the later stage of his career, George was deeply passionate about fighting climate change, and used all his skills to encourage conversations and solutions,” Trahey said.

    “George was a leader in many Basic Energy Science (BES) advisory committee studies and BES workshops. He helped to identify priority research directions for basic science from grand challenges for discovery research to foundations for energy technologies. These reports have literally shaped the BES strategic planning and portfolio for the past decade,” said Harriet Kung, deputy director for Science Programs for DOE’s Office of Science. ​“He was a true renaissance scientist — impacting many disciplines across energy and condensed matter physics. He will be greatly missed by the DOE community.”

    In addition to his work in JCESR, Crabtree also served as co-chair of Argonne’s Action Collaborative, a group of researchers and administrators dedicated to eradicating sexual harassment in the workplace. ​“George cared about making work and life better, more inclusive and more fair for everyone,” Trahey said. ​“He was someone who believed in you and inspired you to believe in yourself.”

    Crabtree is survived by his wife Barbara, a stepson and three grandchildren.

    The Joint Center for Energy Storage Research (JCESR), a DOE Energy Innovation Hub, is a major partnership that integrates researchers from many disciplines to overcome critical scientific and technical barriers and create new breakthrough energy storage technology. Led by the U.S. Department of Energy’s Argonne National Laboratory, partners include national leaders in science and engineering from academia, the private sector, and national laboratories. Their combined expertise spans the full range of the technology-development pipeline from basic research to prototype development to product engineering to market delivery.

    Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.

    The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://​ener​gy​.gov/​s​c​ience.

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  • Brookhaven Lab Battery Scientist, Hydrogeologist, and DOE Site Office Manager Among Secretary of Energy’s 2022 Honorees

    Brookhaven Lab Battery Scientist, Hydrogeologist, and DOE Site Office Manager Among Secretary of Energy’s 2022 Honorees

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    Newswise — UPTON, NY—On January 24, 2023, U.S. Secretary of Energy Jennifer Granholm honored 44 teams with the Secretary of Energy Achievement Award and five individuals for their work. Among the recipients are Distinguished Professor Esther Takeuchi, a battery researcher with a joint appointment at the Department of Energy’s (DOE) Brookhaven National Laboratory and Stony Brook University; Douglas Paquette, a hydrogeologist in Brookhaven Lab’s Environmental Protection Division; and Robert Gordon, manager of the DOE-Brookhaven Site Office that oversees operations at Brookhaven Lab.

    “These awards are among the highest forms of internal, non-monetary recognition DOE Federal and contractor employees can receive,” Secretary Granholm said in a statement. “They are bestowed on individuals and teams in recognition of service which goes above and beyond, and for contributions having lasting impacts on both DOE and on our great Nation. Along with the entire DOE leadership team, I am so proud of the accomplishments of our award recipients. Their commitment to achieving DOE’s mission is an inspiration.”

    Takeuchi was honored for her role on an 80-member team of scientists and support staff from across the DOE National Laboratory complex who facilitated eight virtual panel discussions as part of a Congressional briefing series entitled “Driving U.S. Competitiveness & Innovation: A New Era of Science for Transformative Industry.” The team created a platform for American industry leaders and National Laboratory scientists to speak directly with Congressional staffers. Their goal was to discuss the productivity of public-private collaborations to accelerate emergent technologies and American leadership in artificial intelligence, microelectronics, quantum information sciences, the bioeconomy, and materials and chemistry for clean energy.

    This effort highlighted how capabilities at DOE National Laboratories and their User Facilities (including the National Synchrotron Light Source II and Center for Functional Nanomaterials at Brookhaven Lab) have been used to advance cutting-edge industries and American technical leadership. The discussions also emphasized how partnerships between DOE-supported researchers and American companies can accelerate the Nation’s competitiveness and innovation and address workforce development challenges to prepare for these emergent industries in ways that promote diversity, equity, and inclusion.

    “I was delighted to participate in the topic of ‘Materials and Chemistry for Clean Energy,’” Takeuchi said. “This forum provided a venue to discuss the opportunity for impact of federally funded research and the national labs in strengthening U.S. industrial competitiveness. My discussions featured energy storage as critical to the clean energy transformation including electrifying transportation and adoption of clean energy generation.”

    Paquette and Gordon both served on a team honored for helping DOE formulate a strategy for addressing the impacts of per- and polyfluoroalkyl substances (PFAS). PFAS are a class of widely manufactured chemicals that in recent years have been identified as emerging contaminants of concern in many communities across the United States. Historically, they have been widely used in products such as nonstick pans, water-repellent clothing, and firefighting foams. 

    National focus on PFAS has led to a wide array of Federal and state-level regulatory approaches and policy initiatives. The PFAS Policy Development Team, made up of representatives from multiple DOE offices, coordinated efforts within the DOE and with external stakeholders to better understand and manage the regulations, risks, and liabilities associated with these substances.

    This work enabled DOE to gather information about current and past uses of PFAS; develop policies, guidance documents, and educational materials to support more effective efforts to manage PFAS-related liabilities and constructively engage with internal and external stakeholders; and identify research needs and opportunities to support DOE efforts to develop solutions to PFAS challenges. The coordinated efforts of this team have positioned DOE to engage constructively on an issue of high-level national concern in an informed, proactive, and effective manner.

    “I am honored to be part of the team that was recognized by the Secretary of Energy,” Paquette said. “Over the past four years, the DOE has been proactive in trying to understand the extent of PFAS contamination resulting from past operations and to prevent any new impacts to the environment.”

    The PFAS team recently produced three noteworthy documents including the DOE PFAS Roadmap, the DOE Initial site-by-site PFAS survey, and the DOE Initial PFAS Research and Development Plan. These documents can be found on DOE’s PFAS website at Energy.gov/pfas.

    “Each of these documents highlights Brookhaven Lab’s contributions to PFAS R&D solutions, novel approaches to PFAS remediation, and transparency with the community and regulators,” said Gordon. “It’s not a coincidence that Brookhaven Lab is prominent in DOE’s key PFAS documents; it is because of Brookhaven’s recognized expertise, experience, and willingness to serve as a resource across the DOE enterprise.”

    Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit science.energy.gov.

    Follow @BrookhavenLab on Twitter or find us on Facebook.

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  • KIMM develops the world’s first electrode design for lithium-ion battery that improves smartphone·laptop battery performance

    KIMM develops the world’s first electrode design for lithium-ion battery that improves smartphone·laptop battery performance

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    Newswise — KIMM has announced the development of the design and process technology for the world’s first battery electrode that significantly improves the performance and stability of batteries used in electronic devices such as smartphones, laptops, and electric vehicles.

    A joint research team led by principal researcher Seungmin Hyun of the Department of Nano-Mechanics at the Korea Institute of Machinery and Materials (President Sang-jin Park, hereinafter referred to as KIMM), an institution under the jurisdiction of the Ministry of Science and ICT, and Professor Hoo-jeong Lee of Sungkyunkwan University (President Ji-beom Yoo, hereinafter referred to as SKKU) have developed a new battery technology that uses an electrode (Anode) structure that enhances the reliability and performance of traditional lithium-ion batteries. The results of their research achievement were published in the leading journal Advanced Functional Materials (IF: 19.924)*.

    *Publication title: Design Strategies toward High-Performance Hybrid Carbon Bilayer Anode for Improved Ion Transport and Reaction Stability (Publication date: 2022.11.10)

    In order to develop a design and process technology that maintains high performance and reliability even when the electrode of the lithium-ion battery is thick, the KIMM-SKKU joint research team formed a bilayered anode. Additionally, the anode is designed with grooves allowing small materials with improved ion conductivity and electrical conductivity to be placed between high-capacity materials

    In general, lithium-ion battery electrodes are manufactured by coating and drying a slurry* so that it can be evenly distributed over the entire electrode. As such, it is the uniformity of the slurry that determines the performance of battery. The thicker the electrode, the lower the energy density and uniformity, making it difficult to maintain performance in a high-power environment.

    *Slurry: A mixture of solids and liquids. Specifically, this refers to a mixture of active materials that chemically react to generate electrical energy when a battery is discharged, binders that are added for the structural stabilization of electrodes, and conductive materials that are added to improve electric conductivity.

    However, with the anode structure of this newly developed battery. Uniform reaction stability can be achieved while maintaining high energy density throughout the electrode, even if the electrode is thick. This is particularly helpful in improving the performance and lifespan of batteries.

    Principal researcher Seungmin Hyun stated that this achievement is an efficient method to improve the performance and lifespan of batteries by applying a new design to traditional lithium-ion battery materials and processes. He added that the team will continue to make efforts to apply this new technology to electric vehicles and soft robots that require high energy density in high-power environments, as well as to electronic devices such as commercial smartphones and laptops.

    This research study was carried out with the support of the Nano and Material Technology Development Project (No. 2021M3H4A1A02099352) from the Ministry of Science and ICT, and with the support of the Nano-based Omni-TEX Manufacturing Technology Development Project from KIMM.

     

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    The Korea Institute of Machinery and Materials (KIMM) is a non-profit government-funded research institute under the Ministry of Science and ICT. Since its foundation in 1976, KIMM is contributing to economic growth of the nation by performing R&D on key technologies in machinery and materials, conducting reliability test evaluation, and commercializing the developed products and technologies.

    This research study was carried out with the support of the Nano and Material Technology Development Project (No. 2021M3H4A1A02099352) from the Ministry of Science and ICT, and with the support of the Nano-based Omni-TEX Manufacturing Technology Development Project from KIMM.

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  • Incorporation of water molecules into layered materials impacts ion storage capability

    Incorporation of water molecules into layered materials impacts ion storage capability

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    Newswise — Investigating the interplay between the structure of water molecules that have been incorporated into layered materials such as clays and the configuration of ions in such materials has long proved a great experimental challenge. But researchers have now used a technique elsewhere commonly used to measure extremely tiny masses and molecular interactions at the nano level to observe these interactions for the first time.

    Their research was published in Nature Communications on Oct. 28, 2022.

    Many materials take a layered form at the microscopic or nano-scale. When dry, clays for example resemble a series of sheets stacked upon each other. When such layered materials encounter water however, that water can be confined and integrated into the gaps or holes—or, more accurately, the ‘pores’—between layers.

    Such ‘hydration’ can also occur when water molecules or their constituent elements, notably a hydroxide ion (a negatively charged ion combining a single oxygen and single hydrogen atom) are integrated into the crystalline structure of the material. This type of material, a ‘hydrate’, is not necessarily ‘wet’ even though water is now part of it. Hydration can also substantially change the original material’s structure and properties.

    In this ‘nanoconfinement’, the hydration structures—how water molecules or their constituent elements arrange themselves—determine the ability of the original material to store ions (positively or negatively charged atoms or groups of atoms).

    This storage of water or charge means that such layered materials, from conventional clays to layered metal oxides—and, crucially, their interactions with water—have widespread applications, from water purification to energy storage.

    However, studying the interplay between this hydration structure and the configuration of ions in the ion storage mechanism of such layered materials has proven to be a great challenge. And efforts at analyzing how these hydration structures change over the course of any movement of these ions (‘ion transport’) are even more difficult.

    Recent research has shown that such water structures and interactions with the layered materials play an important role in giving the latter their high ion-storage capacities, all of which in turn depends upon how flexible the layers that host the water are. In the space between layers, any pores that are not filled with ions get filled with water molecules instead, helping to stabilize the layered structure.

    “Put another way, the water structures are sensitive to how the interlayer ions are structured,” said Katsuya Teshima, corresponding author of the study and a materials chemist with the Research Initiative for Supra-Materials at Shinshu University. “And while this ion configuration in many different crystal structures controls how many ions can be stored, such configurations until now had rarely been systematically investigated.”

    So Teshima’s group looked to ‘quartz crystal microbalance with energy dissipation monitoring’ (QCM-D) to assist with their theoretical calculations. QCM-D is essentially an instrument that works like a balance scale that can measure extremely tiny masses and molecular interactions at the nano level. The technique can also measure tiny changes in energy loss.

    The researchers used QCM-D to demonstrate for the first time that the change in the structure of water molecules confined in the nano-space of layered materials can be experimentally observed.

    They did this by measuring the “hardness” of the materials. They investigated the layered double hydroxides (LDHs) of a class of negatively charged clay. They found that the hydration structures were associated with the hardening of the LDHs when any ion exchange reaction happens (a swapping of one kind of ion with a different type of ion but with the same change).

    “In other words, any change in ion interaction originates with the change in the hydration structure that occurs when ions are incorporated into the nano-space,” added Tomohito Sudare, a collaborator on the study now with the University of Tokyo.

    In addition, the researchers found that the hydration structure is highly dependent on the charge density (the amount of charge per unit of volume) of the layered material. This in turn is largely what governs the ion storage capacity.

    The researchers now hope to apply these measurement methods together with the knowledge of the hydration structure of ions to devise new techniques for improving the ion-storage capability of layered materials, potentially opening new avenues for ion separation and sustainable energy storage.

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    About Shinshu University:

    Shinshu University is a national university founded in 1949 located nestling under the Japanese Alps in Nagano known for its stunning natural landscapes. Our motto, “Powered by Nature – strengthening our network with society and applying nature to create innovative solutions for a better tomorrow” reflects the mission of fostering promising creative professionals and deepening the collaborative relationship with local communities, which leads up to our contribution to regional development by innovation in various fields. We’re working on providing solutions for building sustainable society through interdisciplinary research fields: material science (carbon, fiber and composites), biomedical science (for intractable diseases and preventive medicine) and mountain science, and aiming to boost research and innovation capability through collaborative projects with distinguished researchers from the world. For more information visit our website or follow us on Twitter @ShinshuUni for our latest news.

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  • Cornell to lead new semiconductor research center

    Cornell to lead new semiconductor research center

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    Newswise — ITHACA, N.Y. — Cornell is leading a new $34 million research center that will accelerate the creation of energy-efficient semiconductor materials and technologies, and develop revolutionary new approaches for microelectronics systems.

    The SUPeRior Energy-efficient Materials and dEvices (SUPREME) Center will bring together leading researchers from 14 higher education institutions, in collaboration with the center’s sponsor, Semiconductor Research Corporation (SRC). SUPREME is one of seven centers funded by SRC’s JUMP 2.0  consortium. The center will be funded by SRC and its 14 partner universities; Cornell’s investment in the five-year project will be $7 million.

    Partners include: Cornell; Massachusetts Institute of Technology (MIT); Boise State University; Georgia Institute of Technology; North Carolina State University; Northwestern University; Rensselaer Polytechnic Institute; Rochester Institute of Technology; Stanford University; Yale University; the University of Colorado, Boulder; the University of Texas, Austin; the University of California, Santa Barbara; and the University of Notre Dame.

    Huili Grace Xing, the William L. Quackenbush Professor of Engineering in materials science and engineering, and in electrical and computer engineering, at Cornell Engineering, will serve as the center’s director. Tomás Palacios, director of Microsystems Technology Laboratories and a professor in the electrical engineering and computer science at MIT, will serve as the center’s associate director. The center’s managing director will be Thomas Dienel, a condensed matter physicist who has been running the user program at Cornell’s Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials (PARADIM).

    “Our center will focus on the material science, the new device architectures and how they interplay with each other,” said Xing, whose own pioneering research has included materials that support unipolar or bipolar transport, such as 2D materials, ultra-wide bandgap semiconductors, and devices with record performance that reveal fundamental limits.

    “We’re not engineering a particular approach,” she said. “We’re actually going down to the material genome level. If we go down to the building blocks and make a connection, then we can serve a very broad application space in logic, memory, computing, sensing and communication with the desired energy efficiency.

    Researchers at the center will explore both fundamental new science and novel engineering technologies, with the aim of driving the semiconductor industry in the next 3-15 years, while also training the next generation of scientists and engineers to work across disciplines.

    The center’s four primary goals are to:

    • assemble interdisciplinary teams of materials scientists, device engineers, chemists and physicists to develop new materials, technologies and devices that can bring at least 10-fold system-level performance improvements to key applications;
    • accelerate the pace of discovery and “lab-to-fab” transition in microelectronics, creating prototype devices at nanofabrication facilities at Cornell and partner institutions;
    • maintain a close collaboration with six other centers that are part of the latest iteration of the Joint University Microelectronics Program (JUMP) – a consortium of industry research participants and the U.S. Defense Advanced Research Projects Agency (DARPA), which is administered by SRC – with SUPREME developing and demonstrating new materials and technologies that can be used for prototype chips and systems built by other centers in JUMP 2.0; and
    • ensure diverse and broad workforce development.

    “We’ve known for some time that Cornell Engineering faculty are pursuing research at the forefront of semiconductor materials science and engineering,” said Lynden Archer, the Joseph Silbert Dean of Engineering. “With this new multi-institutional research center, we look to the future and to providing leadership that translates to national impact in multiple areas, including autonomous systems and robotics, energy systems, medicine, and space exploration – all fields which require advances in semiconductor materials and new device architectures that consume less energy.”

    SUPREME is organized around four interdisciplinary sub-themes, or thrusts: digital and analog; memory and applications; interconnects and metrology; and materials discovery and processing.

    The first thrust aims to harness the unique properties of two-dimensional materials, wide and ultra-wide bandgap semiconductors, advanced ferroelectrics, spin and molecular materials to develop a new generation of digital and analog devices.

    The second thrust will present new approaches for embedded and neuromorphic memory and storage technologies – such as ferroelectric, spintronic and electrochemical devices – that will support the computational workloads of the future.

    The third thrust will focus on new physics of electron transport and new materials – such as anisotropic conductors and topological semimetals – to engineer better interconnects from devices to devices, and dies to dies. This thrust will also develop advanced metrology to characterize new materials and accelerate material discovery by high throughput experimentation.

    The fourth thrust will develop the new materials and processing technologies required by the first three device-focused thrusts, with an emphasis on several broad classes of materials: 2D and wide bandgap materials for logic and analog computing; metal-oxide-semiconductors for low-power complementary architecture; ferroelectrics and electrochemical materials for new memory/computing architectures, and strongly nonlinear optical materials for interconnects.

    There are seven Cornell faculty among the center’s 25 principal investigators (PIs), including: Xing; Debdeep Jena, the David E. Burr Professor of Engineering in the School of Electrical and Computer Engineering and in the Department of Materials Science and Engineering; James Hwang, M.S. ’76, Ph.D. ’78, a research professor of materials science and engineering; Dan Ralph, Ph.D. ’93, the F.R. Newman Professor of Physics in the College of Arts and Sciences; Farhan Rana, the Joseph P. Ripley Professor of Engineering in electrical and computer engineering; Judy Cha, Ph.D. ’09, professor of materials science and engineering; and Darrell Schlom, the Herbert Fisk Johnson Professor of Industrial Chemistry in materials science and engineering.

    The PIs will also work in close collaboration with industry leaders to maximize the impact and relevance of their work, which will not only lead to more energy-efficiency technologies, but also ultimately boost equality, according to Xing.

    “We want technology that can use as little energy as possible but provide as much function as possible. That is essential if we want to propagate equality,” Xing said. “If we’re able to lower the energy consumption for all of those essential means we want to have in modern life, we can lower the barrier for everybody to have access to information, to have access for education, and to have access to opportunities.”

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    Cornell University

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  • Electronic bridge allows rapid energy sharing between semiconductors

    Electronic bridge allows rapid energy sharing between semiconductors

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    Newswise — As semiconductor devices become ever smaller, researchers are exploring two-dimensional (2D) materials for potential applications in transistors and optoelectronics. Controlling the flow of electricity and heat through these materials is key to their functionality, but first we need to understand the details of those behaviors at atomic scales.

    Now, researchers have discovered that electrons play a surprising role in how energy is transferred between layers of 2D semiconductor materials tungsten diselenide (WSe2) and tungsten disulfide (WS2). Although the layers aren’t tightly bonded to one another, electrons provide a bridge between them that facilitates rapid heat transfer, the researchers found.

    “Our work shows that we need to go beyond the analogy of Lego blocks to understand stacks of disparate 2D materials, even though the layers aren’t strongly bonded to one another,” said Archana Raja, a scientist at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), who led the study. “The seemingly distinct layers, in fact, communicate through shared electronic pathways, allowing us to access and eventually design properties that are greater than the sum of the parts.”

    The study appeared recently in Nature Nanotechnology and combines insights from ultrafast, atomic-scale temperature measurements and extensive theoretical calculations.

    “This experiment was motivated by fundamental questions about atomic motions in nanoscale junctions, but the findings have implications for energy dissipation in futuristic electronic devices,” said Aditya Sood, co-first author of the study and currently a research scientist at Stanford University. “We were curious about how electrons and atomic vibrations couple to one another when heat flows between two materials. By zooming into the interface with atomic precision, we uncovered a surprisingly efficient mechanism for this coupling.”

    An ultrafast thermometer with atomic precision

    The researchers studied devices consisting of stacked monolayers of WSe2 and WS2. The devices were fabricated by Raja’s group at Berkeley Lab’s Molecular Foundry, who perfected the art of using Scotch tape to lift off crystalline monolayers of the semiconductors, each less than a nanometer in thickness. Using polymer stamps aligned under a home-built stacking microscope, these layers were deposited on top of each other and precisely placed over a microscopic window to enable the transmission of electrons through the sample.

    In experiments conducted at the Department of Energy’s SLAC National Accelerator Laboratory, the team used a technique known as ultrafast electron diffraction (UED) to measure the temperatures of the individual layers while optically exciting electrons in just the WSe2 layer. The UED served as an “electron camera”, capturing the atom positions within each layer. By varying the time interval between the excitation and probing pulses by trillionths of a second, they could track the changing temperature of each layer independently, using theoretical simulations to convert the observed atomic movements into temperatures.

    “What this UED approach enables is a new way of directly measuring temperature within this complex heterostructure,” said Aaron Lindenberg, a co-author on the study at Stanford University. “These layers are only a few angstroms apart, and yet we can selectively probe their response and, as a result of the time resolution, can probe at fundamental time scales how energy is shared between these structures in a new way.”

    They found that the WSe2 layer heated up, as expected, but to their surprise, the WS2 layer also heated up in tandem, suggesting a rapid transfer of heat between layers. By contrast, when they didn’t excite electrons in the WSe2 and heated the heterostructure using a metal contact layer instead, the interface between WSe2 and WS2 transmitted heat very poorly, confirming previous reports.

    “It was very surprising to see the two layers heat up almost simultaneously after photoexcitation and it motivated us to zero in on a deeper understanding of what was going on,” said Raja.

    An electronic “glue state” creates a bridge

    To understand their observations, the team employed theoretical calculations, using methods based on density functional theory to model how atoms and electrons behave in these systems with support from the Center for Computational Study of Excited-State Phenomena in Energy Materials (C2SEPEM), a DOE-funded Computational Materials Science Center at Berkeley Lab.

    The researchers conducted extensive calculations of the electronic structure of layered 2D WSe2/WS2, as well as the behavior of lattice vibrations within the layers. Like squirrels traversing a forest canopy, who can run along paths defined by branches and occasionally jump between them, electrons in a material are limited to specific states and transitions (known as scattering), and knowledge of that electronic structure provides a guide to interpreting the experimental results.

    “Using computer simulations, we explored where the electron in one layer initially wanted to scatter to, due to lattice vibrations,” said Jonah Haber, co-first author on the study and now a postdoctoral researcher in the Materials Sciences Division at Berkeley Lab. “We found that it wanted to scatter to this hybrid state – a kind of ‘glue state’ where the electron is hanging out in both layers at the same time. We have a good idea of what these glue states look like now and what their signatures are and that lets us say relatively confidently that other, 2D semiconductor heterostructures will behave the same way.”

    Large-scale molecular dynamics simulations confirmed that, in the absence of the shared electron “glue state”, heat took far longer to move from one layer to another. These simulations were conducted primarily at the National Energy Research Scientific Computing Center (NERSC).

    “The electrons here are doing something important: they are serving as bridges to heat dissipation,” said Felipe de Jornada, a co-author from Stanford University. “If we can understand and control that, it offers a unique approach to thermal management in semiconductor devices.”

    NERSC and the Molecular Foundry are DOE Office of Science user facilities at Berkeley Lab.

    This research was funded primarily by the Department of Energy’s Office of Science.  

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    Founded in 1931 on the belief that the biggest scientific challenges are best addressed by teams, Lawrence Berkeley National Laboratory and its scientists have been recognized with 16 Nobel Prizes. Today, Berkeley Lab researchers develop sustainable energy and environmental solutions, create useful new materials, advance the frontiers of computing, and probe the mysteries of life, matter, and the universe. Scientists from around the world rely on the Lab’s facilities for their own discovery science. Berkeley Lab is a multiprogram national laboratory, managed by the University of California for the U.S. Department of Energy’s Office of Science.

    DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.

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    Lawrence Berkeley National Laboratory

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