Rectifying ionic current with ionoelastomers
Source: ScienceNOW - February 13, 2020 Category: Science Authors: Gao, D., Lee, P. S. Tags: Materials Science perspective Source Type: news
Ionoelastomer junctions between polymer networks of fixed anions and cations
In this study, we demonstrate diodes and transistors using liquid-free ionoelastomers, in which either anions or cations are fixed to an elastomer network and the other ionic species are mobile. The junction of the two ionoelastomers of opposite polarity yields an ionic double layer, which is capable of rectifying and switching ionic currents without electrochemical reactions. The entropically driven depletion of mobile ions creates a junction of tough adhesion, and the stretchability of the junction enables electromechanical transduction. (Source: ScienceNOW)
Source: ScienceNOW - February 13, 2020 Category: Science Authors: Kim, H. J., Chen, B., Suo, Z., Hayward, R. C. Tags: Materials Science reports Source Type: news
Dry reforming of methane by stable Ni-Mo nanocatalysts on single-crystalline MgO
Large-scale carbon fixation requires high-volume chemicals production from carbon dioxide. Dry reforming of methane could provide an economically feasible route if coke- and sintering-resistant catalysts were developed. Here, we report a molybdenum-doped nickel nanocatalyst that is stabilized at the edges of a single-crystalline magnesium oxide (MgO) support and show quantitative production of synthesis gas from dry reforming of methane. The catalyst runs more than 850 hours of continuous operation under 60 liters per unit mass of catalyst per hour reactive gas flow with no detectable coking. Synchrotron studies also show ...
Source: ScienceNOW - February 13, 2020 Category: Science Authors: Song, Y., Ozdemir, E., Ramesh, S., Adishev, A., Subramanian, S., Harale, A., Albuali, M., Fadhel, B. A., Jamal, A., Moon, D., Choi, S. H., Yavuz, C. T. Tags: Chemistry, Materials Science reports Source Type: news
A better way to rebuild cartilage
(Lehigh University) Lesley Chow, an assistant professor of bioengineering and materials science and engineering at Lehigh University received an NSF Faculty Early Career Development Program (CAREER) award. The award supports work she and her team are doing to develop a biomaterial that promotes regeneration of the osteochondral tissue interface. Specifically, refining their 3D-printed material to provide signals to cells that enables the formation of tissue organized in the same way as natural tissue. (Source: EurekAlert! - Medicine and Health)
Source: EurekAlert! - Medicine and Health - February 11, 2020 Category: International Medicine & Public Health Source Type: news
Room-temperature magnetoelastic coupling
Source: ScienceNOW - February 6, 2020 Category: Science Authors: Zhou, Y., Han, S.-T. Tags: Materials Science perspective Source Type: news
Na+-gated water-conducting nanochannels for boosting CO2 conversion to liquid fuels
Robust, gas-impeding water-conduction nanochannels that can sieve water from small gas molecules such as hydrogen (H2), particularly at high temperature and pressure, are desirable for boosting many important reactions severely restricted by water (the major by-product) both thermodynamically and kinetically. Identifying and constructing such nanochannels into large-area separation membranes without introducing extra defects is challenging. We found that sodium ion (Na+)–gated water-conduction nanochannels could be created by assembling NaA zeolite crystals into a continuous, defect-free separation membrane through a...
Source: ScienceNOW - February 6, 2020 Category: Science Authors: Li, H., Qiu, C., Ren, S., Dong, Q., Zhang, S., Zhou, F., Liang, X., Wang, J., Li, S., Yu, M. Tags: Engineering, Materials Science reports Source Type: news
Room temperature magnetoelectric coupling in a molecular ferroelectric ytterbium(III) complex
Magnetoelectric (ME) materials combine magnetic and electric polarizabilities in the same phase, offering a basis for developing high-density data storage and spintronic or low-consumption devices owing to the possibility of triggering one property with the other. Such applications require strong interaction between the constitutive properties, a criterion that is rarely met in classical inorganic ME materials at room temperature. We provide evidence of a strong ME coupling in a paramagnetic ferroelectric lanthanide coordination complex with magnetostrictive phenomenon. The properties of this molecular material suggest tha...
Source: ScienceNOW - February 6, 2020 Category: Science Authors: Long, J., Ivanov, M. S., Khomchenko, V. A., Mamontova, E., Thibaud, J.-M., Rouquette, J., Beaudhuin, M., Granier, D., Ferreira, R. A. S., Carlos, L. D., Donnadieu, B., Henriques, M. S. C., Paixao, J. A., Guari, Y., Larionova, J. Tags: Chemistry, Materials Science reports Source Type: news
Manufacturing Effects on Material Properties
Conclusion Being a part of the 30% - 40% of companies with materials-related recalls can be a detriment to your business. Consider incorporating materials science into your development capabilities and reach out to experts to understand what manufacturing variation could cause material property changes. Assess materials in your risk analysis and especially test for potential variation factors having a direct or confounding effect on your productâs performance. Editor's Note: Stacie Depner will be moderating "Tech Talk Panel:Â Criteria for Choosing the Right Material for Your Device," ...
Source: MDDI - February 3, 2020 Category: Medical Devices Authors: Stacie Depner Tags: Materials Source Type: news
Electricity turns garbage into high-quality graphene
Source: ScienceNOW - January 30, 2020 Category: Science Authors: Service, R. F. Tags: Chemistry, Materials Science In Depth Source Type: news
One-dimensional van der Waals heterostructures
We present the experimental synthesis of one-dimensional (1D) van der Waals heterostructures, a class of materials where different atomic layers are coaxially stacked. We demonstrate the growth of single-crystal layers of hexagonal boron nitride (BN) and molybdenum disulfide (MoS2) crystals on single-walled carbon nanotubes (SWCNTs). For the latter, larger-diameter nanotubes that overcome strain effect were more readily synthesized. We also report a 5-nanometer–diameter heterostructure consisting of an inner SWCNT, a middle three-layer BN nanotube, and an outer MoS2 nanotube. Electron diffraction verifies that all sh...
Source: ScienceNOW - January 30, 2020 Category: Science Authors: Xiang, R., Inoue, T., Zheng, Y., Kumamoto, A., Qian, Y., Sato, Y., Liu, M., Tang, D., Gokhale, D., Guo, J., Hisama, K., Yotsumoto, S., Ogamoto, T., Arai, H., Kobayashi, Y., Zhang, H., Hou, B., Anisimov, A., Maruyama, M., Miyata, Y., Okada, S., Chiashi, S. Tags: Materials Science, Physics r-articles Source Type: news
Ultrahigh thermal conductivity in isotope-enriched cubic boron nitride
Materials with high thermal conductivity () are of technological importance and fundamental interest. We grew cubic boron nitride (cBN) crystals with controlled abundance of boron isotopes and measured greater than 1600 watts per meter-kelvin at room temperature in samples with enriched 10B or 11B. In comparison, we found that the isotope enhancement of is considerably lower for boron phosphide and boron arsenide as the identical isotopic mass disorder becomes increasingly invisible to phonons. The ultrahigh in conjunction with its wide bandgap (6.2 electron volts) makes cBN a promising material for microelectronics therma...
Source: ScienceNOW - January 30, 2020 Category: Science Authors: Chen, K., Song, B., Ravichandran, N. K., Zheng, Q., Chen, X., Lee, H., Sun, H., Li, S., Udalamatta Gamage, G. A. G., Tian, F., Ding, Z., Song, Q., Rai, A., Wu, H., Koirala, P., Schmidt, A. J., Watanabe, K., Lv, B., Ren, Z., Shi, L., Cahill, D. G., Taniguc Tags: Materials Science reports Source Type: news
Crystal symmetry determination in electron diffraction using machine learning
Electron backscatter diffraction (EBSD) is one of the primary tools for crystal structure determination. However, this method requires human input to select potential phases for Hough-based or dictionary pattern matching and is not well suited for phase identification. Automated phase identification is the first step in making EBSD into a high-throughput technique. We used a machine learning–based approach and developed a general methodology for rapid and autonomous identification of the crystal symmetry from EBSD patterns. We evaluated our algorithm with diffraction patterns from materials outside the training set. ...
Source: ScienceNOW - January 30, 2020 Category: Science Authors: Kaufmann, K., Zhu, C., Rosengarten, A. S., Maryanovsky, D., Harrington, T. J., Marin, E., Vecchio, K. S. Tags: Materials Science, Techniques reports Source Type: news
Rational construction of a scalable heterostructured nanorod megalibrary
Integrating multiple materials in arbitrary arrangements within nanoparticles is a prerequisite for advancing many applications. Strategies to synthesize heterostructured nanoparticles are emerging, but they are limited in complexity, scope, and scalability. We introduce two design guidelines, based on interfacial reactivity and crystal structure relations, that enable the rational synthesis of a heterostructured nanorod megalibrary. We define synthetically feasible pathways to 65,520 distinct multicomponent metal sulfide nanorods having as many as 6 materials, 8 segments, and 11 internal interfaces by applying up to seven...
Source: ScienceNOW - January 23, 2020 Category: Science Authors: Steimle, B. C., Fenton, J. L., Schaak, R. E. Tags: Chemistry, Materials Science reports Source Type: news
Phonon hydrodynamics and ultrahigh-room-temperature thermal conductivity in thin graphite
Allotropes of carbon, such as diamond and graphene, are among the best conductors of heat. We monitored the evolution of thermal conductivity in thin graphite as a function of temperature and thickness and found an intimate link between high conductivity, thickness, and phonon hydrodynamics. The room-temperature in-plane thermal conductivity of 8.5-micrometer-thick graphite was 4300 watts per meter-kelvin—a value well above that for diamond and slightly larger than in isotopically purified graphene. Warming enhances thermal diffusivity across a wide temperature range, supporting partially hydrodynamic phonon flow. Th...
Source: ScienceNOW - January 16, 2020 Category: Science Authors: Machida, Y., Matsumoto, N., Isono, T., Behnia, K. Tags: Materials Science, Physics reports Source Type: news
Quantum spin liquids
Spin liquids are quantum phases of matter with a variety of unusual features arising from their topological character, including "fractionalization"—elementary excitations that behave as fractions of an electron. Although there is not yet universally accepted experimental evidence that establishes that any single material has a spin liquid ground state, in the past few years a number of materials have been shown to exhibit distinctive properties that are expected of a quantum spin liquid. Here, we review theoretical and experimental progress in this area. (Source: ScienceNOW)
Source: ScienceNOW - January 16, 2020 Category: Science Authors: Broholm, C., Cava, R. J., Kivelson, S. A., Nocera, D. G., Norman, M. R., Senthil, T. Tags: Materials Science, Online Only, Physics review Source Type: news
Observation of hydrogen trapping at dislocations, grain boundaries, and precipitates
Hydrogen embrittlement of high-strength steel is an obstacle for using these steels in sustainable energy production. Hydrogen embrittlement involves hydrogen-defect interactions at multiple-length scales. However, the challenge of measuring the precise location of hydrogen atoms limits our understanding. Thermal desorption spectroscopy can identify hydrogen retention or trapping, but data cannot be easily linked to the relative contributions of different microstructural features. We used cryo-transfer atom probe tomography to observe hydrogen at specific microstructural features in steels. Direct observation of hydrogen a...
Source: ScienceNOW - January 9, 2020 Category: Science Authors: Chen, Y.-S., Lu, H., Liang, J., Rosenthal, A., Liu, H., Sneddon, G., McCarroll, I., Zhao, Z., Li, W., Guo, A., Cairney, J. M. Tags: Materials Science, Techniques reports Source Type: news
Oriented attachment induces fivefold twins by forming and decomposing high-energy grain boundaries
Natural and synthetic nanoparticles composed of fivefold twinned crystal domains have distinct properties. The formation mechanism of these fivefold twinned nanoparticles is poorly understood. We used in situ high-resolution transmission electron microscopy combined with molecular dynamics simulations to demonstrate that fivefold twinning occurs through repeated oriented attachment of ~3-nanometer gold, platinum, and palladium nanoparticles. We discovered two different mechanisms for forming fivefold twinned nanoparticles that are driven by the accumulation and elimination of strain. This was accompanied by decomposition o...
Source: ScienceNOW - January 2, 2020 Category: Science Authors: Song, M., Zhou, G., Lu, N., Lee, J., Nakouzi, E., Wang, H., Li, D. Tags: Materials Science r-articles Source Type: news
Topological mechanics of knots and tangles
Knots play a fundamental role in the dynamics of biological and physical systems, from DNA to turbulent plasmas, as well as in climbing, weaving, sailing, and surgery. Despite having been studied for centuries, the subtle interplay between topology and mechanics in elastic knots remains poorly understood. Here, we combined optomechanical experiments with theory and simulations to analyze knotted fibers that change their color under mechanical deformations. Exploiting an analogy with long-range ferromagnetic spin systems, we identified simple topological counting rules to predict the relative mechanical stability of knots a...
Source: ScienceNOW - January 2, 2020 Category: Science Authors: Patil, V. P., Sandt, J. D., Kolle, M., Dunkel, J. Tags: Materials Science, Physics reports Source Type: news
Brain-like functions emerging in a metallic nanowire network
(National Institute for Materials Science, Japan) An international joint research team led by NIMS succeeded in fabricating a neuromorphic network composed of numerous metallic nanowires. Using this network, the team was able to generate electrical characteristics similar to those associated with higher order brain functions unique to humans, such as memorization, learning, forgetting, becoming alert and returning to calm. The team then clarified the mechanisms that induced these electrical characteristics. (Source: EurekAlert! - Medicine and Health)
Source: EurekAlert! - Medicine and Health - December 25, 2019 Category: International Medicine & Public Health Source Type: news
Intragranular three-dimensional stress tensor fields in plastically deformed polycrystals
The failure of polycrystalline materials used in infrastructure and transportation can be catastrophic. Multiscale modeling, which requires multiscale measurements of internal stress fields, is the key to predicting the deformation and failure of alloys. We determined the three-dimensional intragranular stress tensor fields in plastically deformed bulk steel using a high-energy x-ray microbeam. We observed intragranular local stresses that deviated greatly from the grain-averaged stresses and exceeded the macroscopic tensile strength. Even under deformation smaller than the uniform elongation, the intragranular stress fiel...
Source: ScienceNOW - December 19, 2019 Category: Science Authors: Hayashi, Y., Setoyama, D., Hirose, Y., Yoshida, T., Kimura, H. Tags: Materials Science reports Source Type: news
Constructive molecular configurations for surface-defect passivation of perovskite photovoltaics
Surface trap–mediated nonradiative charge recombination is a major limit to achieving high-efficiency metal-halide perovskite photovoltaics. The ionic character of perovskite lattice has enabled molecular defect passivation approaches through interaction between functional groups and defects. However, a lack of in-depth understanding of how the molecular configuration influences the passivation effectiveness is a challenge to rational molecule design. Here, the chemical environment of a functional group that is activated for defect passivation was systematically investigated with theophylline, caffeine, and theobromi...
Source: ScienceNOW - December 19, 2019 Category: Science Authors: Wang, R., Xue, J., Wang, K.-L., Wang, Z.-K., Luo, Y., Fenning, D., Xu, G., Nuryyeva, S., Huang, T., Zhao, Y., Yang, J. L., Zhu, J., Wang, M., Tan, S., Yavuz, I., Houk, K. N., Yang, Y. Tags: Materials Science reports Source Type: news
AIs direct search for materials breakthroughs
Source: ScienceNOW - December 12, 2019 Category: Science Authors: Service, R. F. Tags: Engineering, Materials Science In Depth Source Type: news
High strength in combination with high toughness in robust and sustainable polymeric materials
In materials science, there is an intrinsic conflict between high strength and high toughness, which can be resolved for different materials only through the use of innovative design principles. Advanced materials must be highly resistant to both deformation and fracture. We overcome this conflict in man-made polymer fibers and show multifibrillar polyacrylonitrile yarn with a toughness of 137 ± 21 joules per gram in combination with a tensile strength of 1236 ± 40 megapascals. The nearly perfect uniaxial orientation of the fibrils, annealing under tension in the presence of linking molecules, is essential fo...
Source: ScienceNOW - December 12, 2019 Category: Science Authors: Liao, X., Dulle, M., de Souza e Silva, J. M., Wehrspohn, R. B., Agarwal, S., Förster, S., Hou, H., Smith, P., Greiner, A. Tags: Chemistry, Materials Science reports Source Type: news
Wafer-scale synthesis of monolayer two-dimensional porphyrin polymers for hybrid superlattices
We report the synthesis of two-dimensional (2D) porphyrin polymer films with wafer-scale homogeneity in the ultimate limit of monolayer thickness by growing films at a sharp pentane/water interface, which allows the fabrication of their hybrid superlattices. Laminar assembly polymerization of porphyrin monomers could form monolayers of metal-organic frameworks with Cu2+ linkers or covalent organic frameworks with terephthalaldehyde linkers. Both the lattice structures and optical properties of these 2D films were directly controlled by the molecular monomers and polymerization chemistries. The 2D polymers were used to fabr...
Source: ScienceNOW - December 12, 2019 Category: Science Authors: Zhong, Y., Cheng, B., Park, C., Ray, A., Brown, S., Mujid, F., Lee, J.-U., Zhou, H., Suh, J., Lee, K.-H., Mannix, A. J., Kang, K., Sibener, S. J., Muller, D. A., Park, J. Tags: Chemistry, Materials Science reports Source Type: news
A research team develop biotransistors able to hear small beats of live
(Spanish National Research Council (CSIC)) Experts at the Institute for Bioengineering of Catalonia (IBEC), in collaboration with the Institute of Materials Science of Barcelona (ICMAB-CSIC), have achieved a new milestone. By developing a bio-platform that integrates in its core an organic electronic device called Electrolyte Gated Organic Field Effect Transistor (EGOFETs), researchers have been able to monitor the electrical signal of cells and micro-tissues during long periods of time. (Source: EurekAlert! - Medicine and Health)
Source: EurekAlert! - Medicine and Health - December 11, 2019 Category: International Medicine & Public Health Source Type: news
Mayo Clinic, W. L. Gore & amp; Associates announce Avobis Bio, a joint venture for new regenerative therapies
ROCHESTER, Minn., and NEWARK, Del. -- Mayo Clinic and W. L. Gore& Associates Inc., a global materials science company, have formed a joint venture to advance the development of implantable cell therapies to treat debilitating conditions with no cure. Avobis Bio will combine Mayo Clinic's clinical and cell expertise and Gore's expertise in material [...] (Source: Mayo Clinic Business News)
Source: Mayo Clinic Business News - December 10, 2019 Category: Pharmaceuticals Source Type: news
Electrical and optical control of single spins integrated in scalable semiconductor devices
Spin defects in silicon carbide have the advantage of exceptional electron spin coherence combined with a near-infrared spin-photon interface, all in a material amenable to modern semiconductor fabrication. Leveraging these advantages, we integrated highly coherent single neutral divacancy spins in commercially available p-i-n structures and fabricated diodes to modulate the local electrical environment of the defects. These devices enable deterministic charge-state control and broad Stark-shift tuning exceeding 850 gigahertz. We show that charge depletion results in a narrowing of the optical linewidths by more than 50-fo...
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Anderson, C. P., Bourassa, A., Miao, K. C., Wolfowicz, G., Mintun, P. J., Crook, A. L., Abe, H., Ul Hassan, J., Son, N. T., Ohshima, T., Awschalom, D. D. Tags: Physics, Applied, Materials Science r-articles Source Type: news