jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Pablo G. Argudo | Nils Demazy | Guillaume Fleury
Source: Advanced Materials Interfaces (article, 2023-03-28)
Field: Materials Science — Materials Chemistry

Trilayered Block Copolymer Nanostructures Formed by an Iterative Layering Strategy Abstract Nanostructured block copolymer (BCP) thin films enable the formation on‐demand of a variety of periodic patterns at the nanometer scale by tuning the macromolecular BCP characteristics and annealing processes. Significant progress in the control of the self‐assembly has been witnessed over the past decade with the implementation of robust directed self‐assembly methods. However, the self‐assembled structural patterns obtained at equilibrium are limited and methods to expand the range of structural configurations are required to harness additional functionalities. Here, this work demonstrates how polystyrene‐ b ‐poly(methyl methacrylate) BCP thin layers can be stacked to produce a library of complex 3D hierarchical heterostructures. In this iterative assembly process based on simple building bricks (i.e., immobilized BCP patterns forming Holes, Lines and Dots), the stacking configuration (i.e., self‐assembly and registration) of a BCP thin film is directed with respect to the previous layer using confinement effects and interfacial energy tuning. This responsive layering can lead to intricate 3D Al 2 O 3 structures and opens the way to a broad variety of structural designs toward functional applications. Materials science ; Self-assembly ; Nanostructure ; Nanotechnology ; Layering ; Copolymer ; Stacking ; Template ; Nanometre ; Layer by layer ; Annealing (glass) ; Polystyrene ; Thin film ; Composite material ; Polymer Block Copolymer Self-Assembly ; Advanced Polymer Synthesis and Characterization ; Polymer Surface Interaction Studies
Authors: Bilel Abdennadher | René Iseli | Ullrich Steiner | Matthias Saba
Source: Applied Physics A (article, 2023-03-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Broadband circular dichroism in chiral plasmonic woodpiles The circular dichroism (CD) of a material is the difference in optical absorption under left- and right-circularly polarized illumination. It is crucial for a number of applications, from molecular sensing to the design of circularly polarized thermal light sources. The CD in natural materials is typically weak, leading to the exploitation of artificial chiral materials. Layered chiral woodpile structures are well known to boost chiro-optical effects when realized as a photonic crystal or an optical metamaterial. We here demonstrate that light scattering at a chiral plasmonic woodpile, which is structured on the order of the wavelength of the light, can be well understood by considering the fundamental evanescent Floquet states within the structure. In particular, we report a broadband circular polarization bandgap in the complex band structure of various plasmonic woodpiles that spans the optical transparency window of the atmosphere between 3 and 4 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>μ</mml:mi></mml:math> m and leads to an average CD of up to 90% within this spectral range. Our findings could pave the way for an ultra-broadband circularly polarized thermal source. Circular dichroism ; Circular polarization ; Metamaterial ; Plasmon ; Optics ; Broadband ; Optoelectronics ; Polarization (electrochemistry) ; Photonic crystal ; Photonics ; Scattering ; Physics ; Materials science ; Photonic metamaterial ; Crystallography ; Chemistry Metamaterials and Metasurfaces Applications ; Plasmonic and Surface Plasmon Research ; Photonic Crystals and Applications
Authors: Dong Kyo Oh | Nara Jeon | Jong G. Ok | Junsuk Rho
Source: Journal of Flexible and Printed Electronics (article, 2023-06-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Analysis of Nanoparticle-Embedded-Resin Printing Conditions for High-Aspect-Ratio Metasurfaces Metasurfaces, composed of periodic nanostructures, have been attractive because of their extraordinary modulation of light propagation. However, conventional electron-beam lithography to fabricate metasurfaces is time-consuming and costly, which prevents commercialization of functional metasurfaces. We investigate nanoimprint lithography-based technique for single-step fabrication of metasurfaces. A high-refractive-index material is granulated and mixed with nanoimprint resin. This mixture results in higher effective refractive index, and thus can be utilized to directly fabricate metasurfaces. Besides, diverse processing conditions are investigated such as swelling effect for the successful replication of high-aspect-ratio nanostructures. Finally, we verify the optimized nanoparticle-embedded resin printing process through the replication of metasurfaces with various dimensions and an optimal design. Nanoimprint lithography ; Materials science ; Electron-beam lithography ; Lithography ; Nanotechnology ; Nanostructure ; Fabrication ; Replication (statistics) ; Nanolithography ; Refractive index ; Nanoparticle ; 3D printing ; Optoelectronics ; Resist ; Composite material Metamaterials and Metasurfaces Applications ; Photonic Crystals and Applications ; Polydiacetylene-based materials and applications
Authors: D. Dubaux | M.-C. de Weerd | Jaâfar Ghanbaja | Stéphanie Bruyère | A. Redjaïmia | Sylvie Migot | Pascal Boulet | Sašo Šturm | Sorour Semsari Parapari | V. Fournée | M. Sicot | J. Ledieu
Source: Materials Today Communications (article, 2023-12-16)
Field: Materials Science — Materials Chemistry

A novel primitive cubic Al-Fe-Si phase in an Al-0.5Fe-0.2Si (wt.%) alloy Materials science ; Intermetallic ; Alloy ; Ternary operation ; Stoichiometry ; Crystallography ; Phase (matter) ; Arc melting ; Electron diffraction ; Diffraction ; Analytical Chemistry (journal) ; Metallurgy ; Optics ; Physical chemistry Quasicrystal Structures and Properties ; Aluminum Alloy Microstructure Properties ; Microstructure and mechanical properties
Authors: Tariq M. Bhatti | Olli H. Tuovinen
Source: The Nucleus (article, 2023-04-26)
Field: Chemistry — Inorganic Chemistry

Some Historical Briefs and Outlooks of the Chemical and Biological Acid Leaching of Uranium Ores The purpose of this paper is to briefly review early developments in the chemical and biological acid leaching of uranium ores in Portugal, Canada, Sweden, Finland, Estonia, and Pakistan. Uranium exists in tetravalent (U(IV)) and hexavalent (U(VI)) oxidation states in igneous, metamorphic, and sedimentary mineral deposits. Acidic ferric sulfate is a chemical oxidant of tetravalent uranium and is regenerated from ferrous iron in the leachate and produced also from pyrite (FeS2, cubic), marcasite (FeS2, orthorhombic), greigite (Fe3S4) and pyrrhotite (Fe1-xS) by acidophilic Fe- and S-oxidizing bacteria and archaea. The hexavalent uranium is soluble in sulfuric acid solution (lixiviant) and is recovered in downstream hydrometallurgical processing to produce a concentrate (yellowcake). The acid bioleaching reactions are optimal at pH 1.5-3 as the low pH facilitates proton attack on minerals and alleviates the precipitation of metals in the leachate and on mineral surfaces. Uranium is extracted from ores on a commercial scale using heap, dump, and stope leaching processes. In some operations other metals can also be recovered as byproducts in the process. Leaching (pedology) ; Uranium ; Environmental science ; Chemistry ; Environmental chemistry ; Metallurgy ; Materials science ; Soil science Radioactive element chemistry and processing
Authors: Massimigliano Di Luigi | Yu Fu | Zheng Li | Jason N. Armstrong | Fei Yao | Shenqiang Ren
Source: Advanced Engineering Materials (article, 2023-05-11)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Hierarchical Cellulose Superinsulation Membrane The environment‐friendly components coupled with the ability to mimic the simplicity and originality of nature necessitate advanced sustainable materials with structural capabilities for energy‐efficient applications. The use of feedstock deriving from plant‐based, renewable organic material to produce nanofibril that embodies enhanced insulating properties and high mechanical strength constitutes an efficient development strategy. Herein, a free‐standing, hierarchical superinsulation membrane by leveraging the principle of the bottom‐up method is reported. The electrospun cellulose nanofibrils/aerogel‐based core layer provides exceptional thermal properties with its thermal conductivity of 10.2 mW m −1 K −1 . The lightweight, flexible, and durable paper‐like membrane features a tensile strength of 11.3 MPa and a bending rigidity in the order of 4.6 cN mm −1 . The hydrophobic superinsulation membrane material also exhibits a Δ T of ≈25 °C under continuous sunlight illumination and allows thermal runaway mitigation of rechargeable lithium‐ion batteries. All the aforementioned properties position this hybrid superinsulation membrane as a promising material for energy‐saving thermal management applications. Materials science ; Membrane ; Aerogel ; Raw material ; Ultimate tensile strength ; Composite material ; Flexural rigidity ; Renewable energy ; Thermal conductivity ; Cellulose ; Smart material ; Nanotechnology ; Chemical engineering Supercapacitor Materials and Fabrication ; Advanced Sensor and Energy Harvesting Materials ; Dielectric materials and actuators
Authors: Hao Wang | Zonglin Wu | Yue Lu | Hang Zhang | Guang Cheng | Gaojun Liu | Yaozong Bai
Source: Polymer Engineering and Science (article, 2023-11-16)
Field: Materials Science — Materials Chemistry

Understanding the pore structure evolution of polyethylene separator with dissipative particle dynamics simulation Abstract The commercialized lithium‐ion battery separators are mass‐produced by mixing ultra‐high molecular weight polyethylene (UHMWPE) and paraffin oil (PO). The dissipative particle dynamics method is utilized to investigate the extrinsic factors (shear rate and cooling rate) and the intrinsic factors (the molecular chain length) on the microstructure of the UHMWPE‐PO mixture. For the mixture with UHMWPE possessing the same chain length, the high shear rate promoted a lower porosity (~28%) and smaller pores. In contrast, the slow shearing led to a high porosity (~40%) and larger pores. For the mixture with UHMWPE possessing short and long chains, the shear rate hardly affects the porosity and the pore size: the porosity was kept at ~30%, and the pore size was reduced by ~35% compared to the model with the same‐chain‐length UHMWPE. The cooling rate after shearing is the dominant factor in determining the porosity and pore size: the fast cooling raised the porosity by ~33% but hardly increased the pore size, while the slow cooling raised the porosity by ~74%, and the pore size by ~105%. The current study provided a deep understanding of the pore structure evolution in separator processing. Highlights The effects of processing parameters on the pore structures are numerically illustrated. MD simulation and rheometer measurement assist DPD interaction parameters calibration for UHMWPE and PO. The low shear rate leads to a higher porosity and pore size. At the high shear rate, short UHMWPE chains reduce porosity but do not increase pore size. The fast‐cooling process slightly increases the porosity while keeping the pore size. Materials science ; Porosity ; Shearing (physics) ; Polyethylene ; Composite material ; Shear rate ; Dissipative particle dynamics ; Particle size ; Ultra-high-molecular-weight polyethylene ; Microstructure ; Shear (geology) ; Chemical engineering ; Polymer ; Rheology Block Copolymer Self-Assembly ; Electrostatics and Colloid Interactions ; Material Dynamics and Properties
Authors: Jessiel Siaron Gueriba | Hiroshi Mizuseki | Melvin John F. Empizo | Kohei Yamanoi | Nobuhiko Sarukura | Eiichi Tamiya | Yoshiyuki Kawazoe | Kazuaki Akaiwa | Isao Takahashi | Akira Yoshikawa
Source: Japanese Journal of Applied Physics (article, 2023-05-10)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Formation energy crossings in Ga<sub>2</sub>O<sub>3</sub>-Al<sub>2</sub>O<sub>3</sub> quasibinary system: ordered structures and phase transitions in (Al<i> <sub>x</sub> </i>Ga<sub>1−<i>x</i> </sub>)<sub>2</sub>O<sub>3</sub> Abstract A quasibinary system of Ga 2 O 3 -Al 2 O 3 offers a range of applications in wide bandgap semiconductor engineering. Different polymorphs and concentrations of (Al x Ga 1− x ) 2 O 3 manifest a variety of structural and electronic properties, paving the way for tunability of (Al x Ga 1− x ) 2 O 3 for specific functions. In this work, we investigate the energetics of alpha ( α ) and beta ( β ) polymorphs of Ga 2 O 3 and Al 2 O 3 by considering all possible configurations in a conventional unit cell. Using density functional theory, we show that the formation energies of (Al x Ga 1− x ) 2 O 3 in α and β configurations start to coincide at 50% concentration (Al 0.5 Ga 0.5 ) 2 O 3 . The corundum configuration then becomes more dominant (lower in energy) than its monoclinic counterpart at around 80% Al concentration. The lowest formation energy configurations for 50% concentration in both α and β polymorphs also manifest a preference towards an ordered phase. These show that the stability of Ga 2 O 3 -Al 2 O 3 and its phase transitions are significantly influenced by the relative arrangements of Ga and Al within the quasibinary semiconducting crystal. Monoclinic crystal system ; Corundum ; Crystallography ; Chemistry ; Polymorphism (computer science) ; Lattice energy ; Crystal structure ; Mineralogy Ga2O3 and related materials ; Advanced Photocatalysis Techniques ; ZnO doping and properties
Authors: Dehbiya Gherdaoui | Madiha Melha Yahoum | Selma Toumi | Hichem Tahraoui | Fatma Bouazza | Sonia Lefnaoui | Abdelhamid Zeghdaoui | Abdeltif Amrane | Bassem Jaouadi | Jie Zhang
Source: Symmetry (article, 2023-12-04)
Field: Chemistry — Spectroscopy

The Effect of the Stationary Phase on Resolution in the HPLC-Based Separation of Racemic Mixtures Using Vancomycin as a Chiral Selector: A Case Study with Profen Nonsteroidal Anti-Inflammatory Drugs Chiral resolution is a technique of choice, making it possible to obtain asymmetric and enantiomerically pure compounds from a racemic mixture. This study investigated the behavior of vancomycin when used as a chiral additive in high-performance liquid chromatography (HPLC) to separate enantiomers of nonsteroidal anti-inflammatory drugs (NSAIDs), including ketoprofen, ibuprofen, flurbiprofen, and naproxen enantiomeric impurities. We compared two achiral stationary phases (C18 and NH2) to assess the impact of mobile phase composition and stationary phase on the vancomycin retention time in the racemic resolution of drug enantiomers. Our results demonstrated the successful enantioseparation of all drugs using vancomycin in the mobile phase (phosphate buffer 0.05 M/2-propanol, 50/50) with an NH2 column. This enhanced separation on the NH2 column resulted from the chromatography system’s efficiency and vancomycin dimers’ stereoselective interaction on the NH2 surface. This study underscores the importance of stationary phase selection in the chiral resolution of NSAIDs with vancomycin as a chiral additive. It offers valuable insights for future research and development of NSAID chiral separation methods, highlighting potential vancomycin applications in this context. Enantiomer ; Chiral stationary phase ; Chemistry ; Vancomycin ; Chiral column chromatography ; High-performance liquid chromatography ; Chromatography ; Ketoprofen ; Resolution (logic) ; Flurbiprofen ; Naproxen ; Organic chemistry ; Pharmacology ; Staphylococcus aureus ; Medicine Analytical Chemistry and Chromatography ; Microfluidic and Capillary Electrophoresis Applications ; Mass Spectrometry Techniques and Applications
Authors: Maike Käärik | Mati Arulepp | Jaan Leis
Source: Molecules (article, 2023-03-25)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Partial Oxidation to Extend the Lifetime of Nanoporous Carbon in an Ultracapacitor with Li2SO4 Electrolyte A TiC-derived carbon (CDC) and its partially oxidized derivative (ox-red-CDC), oxidized by a modified Hummers method, were studied as promising electrode materials for electrochemical energy storage. To evaluate the electrochemical properties of the carbon materials, cyclic voltammetry, galvanostatic cycling, and electrochemical impedance spectroscopy measurements were performed in 1 M Li<sub>2</sub>SO<sub>4</sub> using 2- and 3-electrode cells. A partially oxidized surface was shown to improve the capacitance and electrochemical stability of a nanoporous CDC at positive potential values. The respective anodic capacitance of 80 F cm<sup>-3</sup> reveals a 15% improvement over the non-oxidized CDC. At negative potential values, the capacitance of two carbon materials is almost equal, 97 vs. 93 F cm<sup>-3</sup>, for the non-oxidized and partially oxidized CDC materials, respectively. An asymmetric 2-electrode ultracapacitor containing ox-red-CDC as the anode and pristine CDC as the cathode demonstrated an excellent cycle life. The temporary repolarization of the 2-electrode cell after thousands of charge-discharge cycles increased the capacitance and improved the cycling characteristics, likely due to regeneration and cleaning of the electrode surface. Dielectric spectroscopy ; Supercapacitor ; Cyclic voltammetry ; Electrochemistry ; Electrode ; Electrolyte ; Materials science ; Capacitance ; Nanoporous ; Anode ; Carbon fibers ; Chemical engineering ; Inorganic chemistry ; Analytical Chemistry (journal) ; Chemistry ; Nanotechnology ; Composite material ; Organic chemistry Supercapacitor Materials and Fabrication ; Advancements in Battery Materials ; Electrocatalysts for Energy Conversion
Authors: Vladyslav Polishchuk | Mykola P. Shandura
Source: Journal of organic and pharmaceutical chemistry (article, 2023-04-28)
Field: Materials Science — Materials Chemistry

Polymethine Dyes Based on 2,2-Difluoro-1,3,2-dioxaborine: a Minireview Aim. To summarize and analyze literature data on the polymethine dyes containing the 2,2-difluoro-1,3,2-dioxaborine ring.Results and discussion. Boron difluoride complex of β-diketone (2,2-difluoro-1,3,2-dioxaborine, F2DB) is a unique structural motif endowing organic compounds with prominent physicochemical properties, such as a strong fluorescence and high mo-lar attenuation coefficients. Incorporation of the F2DB core into a polymethine chromophore either as an end-group or as an integral part of the polymethine chain allows obtaining dyes with exceptional characteristics, highly appealing for design of up-to-date functional materials. This review focuses on the synthesis and spectral properties of the F2DB-containing polymethines along with the latest advancement in the synthesis of highly fluorescent polyanionic polymethines. A brief discussion of the effects of the structural modification of the π-conjugated system on the photophysical properties of dyes is included.Conclusions. The literature on the F2DB-containing polymethines demonstrates a high potential of the F2DB core for the development of strongly fluorescent and intensely absorbing dyes. Chromophore ; Fluorescence ; Conjugated system ; Chemistry ; Ring (chemistry) ; Combinatorial chemistry ; Photochemistry ; Organic chemistry ; Polymer ; Physics Luminescence and Fluorescent Materials ; Molecular Sensors and Ion Detection ; Conducting polymers and applications
Authors: Shuanghe Chi | Jinxing Guo | Zhengli Hua | Juan Shang | Baihui Xing
Source: Energies (article, 2023-10-17)
Field: Materials Science — Metals and Alloys

Analysis of Hydrogen Distribution and Diffusion in Pre-Strained SUS316L through Scanning Kelvin Probe Force Microscopy and Thermal Desorption Spectroscopy Austenitic stainless steels (γ-SS) play an important role in the storage of high-pressure hydrogen. However, hydrogen embrittlement (HE) can significantly degrade the mechanical properties of γ-SS. Measuring the distribution of hydrogen in γ-SS is a vital way to learn about HE. In this paper, scanning Kelvin probe force microscopy (SKPFM) and thermal desorption spectroscopy (TDS) have been utilized to analyze the distribution and diffusion of hydrogen in pre-strained SUS316L. Additionally, the McNabb–Foster model is employed to calculate hydrogen in the lattice and phase boundaries along the sample’s thickness direction. The results demonstrate that the combination of SKPFM and TDS is an effective approach for studying hydrogen distribution and diffusion in metals. It was observed that hydrogen segregation occurs at the boundary between the martensitic (α′) and austenite (γ) phases. The inhibitory effect of the oxide film on hydrogen diffusion is more significant at lower temperatures. However, it should be noted that the McNabb–Foster model exhibits relatively high accuracy in predicting hydrogen desorption at higher temperatures while disregarding the influence of the native oxide film. Kelvin probe force microscope ; Hydrogen ; Materials science ; Thermal desorption spectroscopy ; Thermal desorption ; Oxide ; Desorption ; Hydrogen embrittlement ; Analytical Chemistry (journal) ; Diffusion ; Spectroscopy ; Chemistry ; Metallurgy ; Thermodynamics ; Nanotechnology ; Atomic force microscopy ; Corrosion ; Physical chemistry ; Adsorption Hydrogen embrittlement and corrosion behaviors in metals ; Corrosion Behavior and Inhibition ; Force Microscopy Techniques and Applications
Authors: A. Fernández García | Mario García-Lechuga | F. Agulló‐Rueda | J. Rubio Zuazo | M. Manso Silvan
Source: Surfaces and Interfaces (article, 2023-11-23)
Field: Materials Science — Materials Chemistry

Femtosecond laser thinning for resistivity control of tungsten ditelluride thin-films synthesized from sol-gel deposited tungsten oxide In this work we present a route for fabricating WTe2 thin-films together with femtosecond laser post processing, enabling to finely control the conductivity. First, we produce amorphous films of WO3 on Si by spin-coating a sol-gel precursor followed by a consolidating annealing and a reduction process in partial H2 atmosphere, leading to porous metallic tungsten cluster layers. To achieve WTe2, the films were exposed to the chalcogen vapours by isothermal closed space vapor transport. The formation of a tungsten ditelluride film composed of piled crystals could be confirmed and a gradient of surface rich Te identified through hard X-ray photoelectron spectroscopy. Finally, it is demonstrated that resistivity can be changed from 0.2 mΩ.m to 1 mΩ.m, while keeping the material characteristics. An anisotropic conductivity can be induced by direct selective thinning with fs laser writing (350 fs pulse duration, 515 nm laser wavelength) of 1D stripes. The obtained results, demonstrate that laser processing is a promising thin-film post-processing technique that can be applied to 2D transition metal dichalcogenide thin films. Materials science ; Thin film ; Amorphous solid ; Tungsten ; Femtosecond ; Electrical resistivity and conductivity ; Laser ; Annealing (glass) ; Optoelectronics ; Analytical Chemistry (journal) ; Optics ; Nanotechnology ; Composite material ; Metallurgy ; Crystallography 2D Materials and Applications ; Chalcogenide Semiconductor Thin Films ; Quantum Dots Synthesis And Properties