jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Sofia Stefa | Maria Lykaki | Vassiliοs Binas | Pavlos K. Pandis | Vassilis N. Stathopoulos | Michalis Konsolakis
Source: Applied Sciences (article, 2020-10-28)
Field: Materials Science — Materials Chemistry

Hydrothermal Synthesis of ZnO–doped Ceria Nanorods: Effect of ZnO Content on the Redox Properties and the CO Oxidation Performance The rational design of highly efficient, noble metal-free metal oxides is one of the main research priorities in the area of catalysis. To this end, the fine tuning of ceria-based mixed oxides by means of aliovalent metal doping has currently received particular attention due to the peculiar metal-ceria synergistic interactions. Herein, we report on the synthesis, characterization and catalytic evaluation of ZnO–doped ceria nanorods (NR). In particular, a series of bare CeO2 and ZnO oxides along with CeO2/ZnO mixed oxides of different Zn/Ce atomic ratios (0.2, 0.4, 0.6) were prepared by the hydrothermal method. All prepared samples were characterized by X-ray diffraction (XRD), N2 physisorption, temperature-programmed reduction (TPR), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) and transmission electron microscopy (TEM). The CO oxidation reaction was employed as a probe reaction to gain insight into structure-property relationships. The results clearly showed the superiority of mixed oxides as compared to bare ones, which could be ascribed to a synergistic ZnO–CeO2 interaction towards an improved reducibility and oxygen mobility. A close correlation between the catalytic activity and oxygen storage capacity (OSC) was disclosed. Comparison with relevant literature studies verifies the role of OSC as a key activity descriptor for reactions following a redox-type mechanism. Nanorod ; Redox ; Catalysis ; Materials science ; Physisorption ; Chemical engineering ; Hydrothermal circulation ; Metal ; Noble metal ; Inorganic chemistry ; Doping ; Scanning electron microscope ; Nanotechnology ; Chemistry ; Metallurgy Catalytic Processes in Materials Science ; Electrocatalysts for Energy Conversion ; Copper-based nanomaterials and applications
Authors: Rafaela Lopes | Marlene Costa | Mariana Ferreira | Paula Gameiro | Fátima Paiva‐Martins
Source: Biochimica et Biophysica Acta (BBA) - Biomembranes (article, 2020-12-03)
Field: Chemistry — Organic Chemistry

A new family of hydroxytyrosol phenolipids for the antioxidant protection of liposomal systems Hydroxytyrosol ; Antioxidant ; Liposome ; Chemistry ; Pharmacology ; Traditional medicine ; Medicine ; Biochemistry ; Polyphenol Free Radicals and Antioxidants ; Phytochemicals and Antioxidant Activities ; Antioxidant Activity and Oxidative Stress
Authors: Jorune Sakalauskaite | Laurent Plasseraud | Jérôme Thomas | Marie Albéric | Mathieu Thoury | Jonathan Perrin | Frédéric Jamme | Cédric Broussard | Beatrice Demarchi | Frédéric Marin
Source: Journal of Structural Biology (article, 2020-03-24)
Field: Materials Science — Biomaterials

The shell matrix of the european thorny oyster, Spondylus gaederopus: microstructural and molecular characterization Biomineralization ; Shell (structure) ; Evolutionary biology ; Biology ; Chemistry ; Astrobiology ; Materials science Calcium Carbonate Crystallization and Inhibition ; Paleontology and Stratigraphy of Fossils ; Bone Tissue Engineering Materials
Authors: Jingyu Li | Jinfeng Yang | Beibei Shi | Wenya Zhai | Chi Zhang | Yuli Yan | Pengfei Liu
Source: Physical Chemistry Chemical Physics (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Ternary multicomponent Ba/Mg/Si compounds with inherent bonding hierarchy and rattling Ba atoms toward low lattice thermal conductivity Compositional tailoring externally enables the fine tuning of thermal transport parameters of materials using the dual modulation of electronic or thermal transport properties. Theoretically, we examined the lattice dynamics of three particularly ternary representatives with different stoichiometry, BaMgSi, Ba<sub>2</sub>Mg<sub>3</sub>Si<sub>4</sub>, and BaMg<sub>2</sub>Si<sub>2</sub>, and identified the inherent bonding hierarchy and rattling Ba atoms, which were responsible for reducing the lattice thermal conductivity. BaMgSi and Ba<sub>2</sub>Mg<sub>3</sub>Si<sub>4</sub> exhibited inherently ultra-low lattice thermal conductivity of 1.27-0.37 W m<sup>-1</sup> K<sup>-1</sup> in the range of 300-1000 K due to the bonding hierarchy and rattling Ba atoms. The low-energy optical phonons are overlapping with the acoustic phonons. This is associated with the intrinsic rattler-like vibration of Ba cations and leads to the characteristic in the localization of the propagative phonons and large anharmonicity. Although BaMg<sub>2</sub>Si<sub>2</sub> had a dumbbell-shaped Si-Si covalent and Ba-Si/Mg ionic bonding environment and intrinsic rattler-like vibration of Ba cations, the middle frequency optic phonon branches contribute considerably to the thermal conductivity of the lattice. At the same temperature, compared with BaMgSi and Ba<sub>2</sub>Mg<sub>3</sub>Si<sub>4</sub>, the lattice thermal conductivity of BaMg<sub>2</sub>Si<sub>2</sub> almost doubles owing to the higher phonon lifetime and group velocities. Our findings highlight considerable potential for thermoelectric applications with a different stoichiometric ratio of Ba/Mg/Si systems due to their low lattice thermal conductivities via intrinsic modulating stoichiometry. Ternary operation ; Thermal conductivity ; Lattice (music) ; Materials science ; Crystallography ; Chemistry ; Condensed matter physics ; Physics ; Computer science ; Composite material Advanced Thermoelectric Materials and Devices ; Thermal properties of materials ; Thermal Expansion and Ionic Conductivity
Authors: Xue‐Song Zhou | Dongmei Yan | Jia‐Rong Chen
Source: Chem (article, 2020-03-23)
Field: Chemistry — Organic Chemistry

Halogen-Atom Transfer Activation of Halides by Aminoalkyl Radicals Chemistry ; Radical ; Aryl ; Halide ; Halogen ; Alkyl ; Reagent ; Organic synthesis ; Halogen bond ; Electron transfer ; Photochemistry ; Hydride ; Reactive intermediate ; Combinatorial chemistry ; Organic chemistry ; Catalysis ; Metal Radical Photochemical Reactions ; Catalytic C–H Functionalization Methods ; Sulfur-Based Synthesis Techniques
Authors: Chunman Jia | Dawei Qi | Yucang Zhang | Kari Rissanen | Jianwei Li
Source: ChemSystemsChem (article, 2020-04-22)
Field: Chemistry — Organic Chemistry

Strategies for Exploring Functions from Dynamic Combinatorial Libraries Abstract Dynamic combinatorial chemistry (DCC) is a powerful approach for creating complex chemical systems, giving access to the studies of complexity and exploration of functionality in synthetic systems. However, compared with more advanced living systems, the man‐made chemical systems are still less functional, due to their limited complexity and insufficient kinetic control. Here we start by introducing strategies to enrich the complexity of dynamic combinatorial libraries (DCLs) for exploiting unexpected functions by increasing the species of building blocks and/or templates used. Then, we discuss how dynamic isomerization of photo‐switchable molecules help DCLs increase and alter the systemic complexity in‐situ . Multi‐phase DCLs will also be reviewed to thrive complexity and functionality across the interfaces. Finally, there will be a summary and outlook about remote kinetic control in DCLs that are realized by applying exogenous physical transduction signals of stress, light, heat and ultrasound. Computer science ; Template ; Nanotechnology ; Biochemical engineering ; Materials science ; Engineering Supramolecular Chemistry and Complexes ; Supramolecular Self-Assembly in Materials ; Chemical Synthesis and Analysis
Authors: Ana Cadena | Bea Botka | K. Kamarás
Source: Oxford Open Materials Science (article, 2020-11-23)
Field: Materials Science — Materials Chemistry

Organic molecules encapsulated in single-walled carbon nanotubes Abstract Hybrid materials based on carbon nanotubes continue to attract considerable interest due to the broad variety of both the cages outside and the encapsulated species inside. This review focuses on organic molecules as guests in single-walled carbon nanotube hosts. The majority of results presented here has been attained in recent years by various methods of optical spectroscopy, complemented by transmission electron microscopy. These spectroscopic methods yield information on electronic structure, as well as dynamic processes as structural transformations and chemical reactions. Carbon nanotube ; Nanotechnology ; Materials science ; Molecule ; Transmission electron microscopy ; Carbon fibers ; Organic molecules ; Yield (engineering) ; Chemical engineering ; Chemistry ; Organic chemistry ; Composite material ; Composite number Carbon Nanotubes in Composites ; Graphene research and applications ; Fullerene Chemistry and Applications
Authors: Hyeyeon Cho | Yohwan Park | Soyoung Kim | Taemin Ahn | Tae-Hwan Kim | Hee Cheul Choi
Source: npj 2D Materials and Applications (article, 2020-10-13)
Field: Materials Science — Materials Chemistry

Specific stacking angles of bilayer graphene grown on atomic-flat and -stepped Cu surfaces Abstract Bilayer graphene (BLG) exhibits unique properties depending on a stacking angle between the two layers of graphene. Although it has been known that BLGs having stacking angles of 0° and 30° can be obtained by chemical vapor deposition (CVD), not much is known yet about the effect of copper (Cu) surface on the decision of stacking angle, through which further fine control of the stacking angle could be possible. Here, we report that the crystal plane of Cu catalyst plays a critical role in the selection of the stacking angle of BLG, and provide experimental and computational evidence that an atomic-flat Cu (111) surface generates BLGs having 0° and 30° of stacking angle, while atomic-stepped Cu (311) and Cu (110) surfaces mainly produce small stacking angle BLGs with 3–5° of stacking angle as a major product by CVD. Stacking ; Materials science ; Graphene ; Bilayer ; Bilayer graphene ; Crystallography ; Crystal (programming language) ; Chemical vapor deposition ; Copper ; Nanotechnology ; Chemistry ; Organic chemistry Graphene research and applications ; 2D Materials and Applications ; Diamond and Carbon-based Materials Research
Authors: Jean-Emile Potaufeux | Jérémy Odent | Delphine Notta‐Cuvier | Rémi Delille | Sophie Barrau | Emmanuel P. Giannelis | Franck Lauro | Jean‐Marie Raquez
Source: Composites Science and Technology (article, 2020-02-17)
Field: Materials Science — Biomaterials

Mechanistic insights on ultra-tough polylactide-based ionic nanocomposites Materials science ; Nanocomposite ; Toughness ; Composite material ; Small-angle X-ray scattering ; Ultimate tensile strength ; Thermal stability ; Polyurethane ; Ionic bonding ; Extrusion ; Cationic polymerization ; Ethylene glycol ; Polymer ; Chemical engineering ; Polymer chemistry ; Scattering ; Organic chemistry biodegradable polymer synthesis and properties ; Polymer composites and self-healing ; Polymer Nanocomposites and Properties
Authors: Paulo N. Martinho | Frederico F. Martins | Nuno A. G. Bandeira | Maria José Calhorda
Source: Sustainability (article, 2020-03-23)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Spin Crossover in 3D Metal Centers Binding Halide-Containing Ligands: Magnetism, Structure and Computational Studies The capability of a given substance to change its spin state by the action of a stimulus, such as a change in temperature, is by itself a very challenging property. Its interest is increased by the potential applications and the need to find sustainable functional materials. 3D transition metal complexes, mainly with octahedral geometry, display this property when coordinated to particular sets of ligands. The prediction of this behavior has been attempted by many authors. It is, however, made very difficult because spin crossover (SCO), as it is called, occurs most often in the solid state, where besides complexes, counter ions, and solvents are also present in many cases. Intermolecular interactions definitely play a major role in SCO. In this review, we decided to analyze SCO in mono- and binuclear transition metal complexes containing halogens as ligands or as substituents of the ligands. The aim was to try and find trends in the properties which might be correlated to halogen substitution patterns. Besides a revision of the properties, we analyzed structures and other information. We also tried to build a simple model to run Density Functional Theory (DFT) calculations and calculate several parameters hoping to find correlations between calculated indices and SCO data. Although there are many experimental studies and single-crystal X-ray diffraction structures, there are only few examples with the F, Cl, Br and series. When their intermolecular interactions were not very different, T1/2 (temperature with 50% high spin and 50% low spin states) usually increased with the calculated ligand field parameter (Δoct) within a given family. A way to predict SCO remains elusive. Halogen ; Density functional theory ; Spin crossover ; Spin states ; Intermolecular force ; Magnetism ; Chemistry ; Halide ; Transition metal ; Crystallography ; Crystal engineering ; Octahedron ; Computational chemistry ; Halogen bond ; Ligand field theory ; Chemical physics ; Crystal structure ; Ion ; Molecule ; Supramolecular chemistry ; Inorganic chemistry ; Physics ; Condensed matter physics ; Organic chemistry Magnetism in coordination complexes ; Metal complexes synthesis and properties ; Lanthanide and Transition Metal Complexes
Authors: Marina G. Shelyapina | Oleg I. Silyukov | Irina P. Lushpinskaia | Sergei A. Kurnosenko | Anton S. Mazur | Ilya G. Shenderovich | Irina A. Zvereva
Source: Molecules (article, 2020-11-10)
Field: Materials Science — Materials Chemistry

NMR Study of Intercalates and Grafted Organic Derivatives of H2La2Ti3O10 The protonated perovskite-like titanate H<sub>2</sub>La<sub>2</sub>Ti<sub>3</sub>O<sub>10</sub> has been used to produce organic-inorganic hybrids with simple organic molecules: methylamine, methanol, monoethanolamine, and <i>n</i>-butylamine. The optimal pathways for the preparation of such hybrids are summarized. Solid-state NMR, combined with thermal analysis, Raman, and IR spectroscopy, has been applied to determine the bonding type in the obtained organic-inorganic hybrids. It has been found that, in the methanolic hybrid, the organic residues are covalently bound to the inorganic matrix. In contrast, in the methylamine and <i>n</i>-butylamine hybrids, the organic molecules are intercalated into the inorganic matrix in cationic forms. The structure of the monoethanolamine hybrid is composite and includes both the covalently bound and intercalated organic species. Methylamine ; Intercalation (chemistry) ; Butylamine ; Hybrid material ; Covalent bond ; Chemistry ; Molecule ; Protonation ; Organic base ; Cationic polymerization ; Solid-state nuclear magnetic resonance ; Raman spectroscopy ; Organic chemistry ; Polymer chemistry ; Inorganic chemistry ; Materials science ; Amine gas treating Layered Double Hydroxides Synthesis and Applications ; Advanced Battery Materials and Technologies ; Polyoxometalates: Synthesis and Applications
Authors: Rosália Lopes Rodrigues | Fang Xie | Alexandra E. Porter | Mary P. Ryan
Source: Nanoscale Advances (article, 2020-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Geometry-induced protein reorientation on the spikes of plasmonic gold nanostars Functionalized gold nanostars (AuStrs) are remarkable candidates for drug delivery, photothermal therapy and imaging due to their large surface area to volume ratio and plasmonic properties. In this study, we address the challenge of achieving therapeutically controlled dosing using these high aspect ratio nanoparticle vectors by tailoring the nanostar loading area and protein conformation. We synthesized a library of different Au nanostars with varied geometries for potential biomedical applications. The Au nanostars were subsequently coated with different amounts of transferrin (Tf) and a novel depletion method was devised to measure the amount of Tf bound to the surface of the nanostructures. This methodology allowed us to show that coating thickness could be controllably varied and moulded onto the nanoparticle's high index features, whilst simultaneously preserving the key properties of the particle. The orientation of the Tf was measured on nanostars and spheres using transmission electron microscopy by negatively staining the Tf. The Tf was conformal on the nanostars, and protein packing efficiency increased on the AuStrs by 14-fold due to a geometry-induced protein reorientation at the nanoparticle surface. Interestingly, the reorientation of the transferrin observed at the AuStrs spikes did not occur at the AuStrs tips thus highlighting surface energy effects associated with surface curvature. Materials science ; Nanoparticle ; Nanotechnology ; Plasmon ; Photothermal therapy ; Transmission electron microscopy ; Nanostructure ; Drug delivery ; Curvature ; Transferrin ; Chemistry ; Optoelectronics ; Geometry Gold and Silver Nanoparticles Synthesis and Applications ; Nanoparticle-Based Drug Delivery ; Plasmonic and Surface Plasmon Research
Authors: L.G. Iacovino | Simone Savino | Annika J. E. Borg | Claudia Binda | Bernd Nidetzky | Andrea Mattevi
Source: Journal of Biological Chemistry (article, 2020-07-13)
Field: Materials Science — Materials Chemistry

Crystallographic snapshots of UDP-glucuronic acid 4-epimerase ligand binding, rotation, and reduction UDP-glucuronic acid is converted to UDP-galacturonic acid en route to a variety of sugar-containing metabolites. This reaction is performed by a NAD<sup>+</sup>-dependent epimerase belonging to the short-chain dehydrogenase/reductase family. We present several high-resolution crystal structures of the UDP-glucuronic acid epimerase from <i>Bacillus cereus</i> The geometry of the substrate-NAD<sup>+</sup> interactions is finely arranged to promote hydride transfer. The exquisite complementarity between glucuronic acid and its binding site is highlighted by the observation that the unligated cavity is occupied by a cluster of ordered waters whose positions overlap the polar groups of the sugar substrate. Co-crystallization experiments led to a structure where substrate- and product-bound enzymes coexist within the same crystal. This equilibrium structure reveals the basis for a "swing and flip" rotation of the pro-chiral 4-keto-hexose-uronic acid intermediate that results from glucuronic acid oxidation, placing the C4' atom in position for receiving a hydride ion on the opposite side of the sugar ring. The product-bound active site is almost identical to that of the substrate-bound structure and satisfies all hydrogen-bonding requirements of the ligand. The structure of the apoenzyme together with the kinetic isotope effect and mutagenesis experiments further outlines a few flexible loops that exist in discrete conformations, imparting structural malleability required for ligand rotation while avoiding leakage of the catalytic intermediate and/or side reactions. These data highlight the double nature of the enzymatic mechanism: the active site features a high degree of precision in substrate recognition combined with the flexibility required for intermediate rotation. Chemistry ; Stereochemistry ; Active site ; Crystallography ; Ligand (biochemistry) ; Glucuronic acid ; Substrate (aquarium) ; Hydride ; Enzyme ; Biochemistry ; Organic chemistry ; Hydrogen Enzyme Structure and Function ; Diet, Metabolism, and Disease ; Biochemical and Molecular Research
Authors: Alex J. Lopez‐Garcia | A. Bauer | Robert Fonoll‐Rubio | David Payno | Zacharie Jehl Li‐Kao | Samrana Kazim | Dimitrios Hariskos | Víctor Izquierdo‐Roca | Edgardo Saucedo | Alejandro Pérez‐Rodríguez
Source: Solar RRL (article, 2020-09-19)
Field: Materials Science — Materials Chemistry

UV‐Selective Optically Transparent Zn(O,S)‐Based Solar Cells This work reports experimental evidence of a photovoltaic effect in transparent UV‐selective Zn(O,S)‐based heterojunctions. Zn(O,S) has a strong interest for the development of UV‐selective solar cells with high transparency in the visible region, required for the development of nonintrusive building‐integrated photovoltaic (BIPV) elements as transparent solar windows and glass‐based solar façades. By anion alloying, Zn(O,S) mixed crystal absorbers can be fabricated with different sulfur content across the whole compositional range. This allows adjustment of the bandgap of the absorbers in the 2.7–2.9 eV region, maximizing absorption in the UV, while keeping a high level of transparency. Zn(O,S) alloys with composition corresponding to S/(S + O) content ratios of 0.6 are successfully grown by sputtering deposition, and first glass/FTO/NiO/Zn(O,S)/ITO device prototypes are produced. The resulting devices present an average visible transmittance (AVT) of 75% and present photovoltaic effect. By introducing a thin C 60 film as electron transport layer (ETL), charge extraction is enhanced, and devices show an efficiency of 0.5% and an AVT &gt; 69%. The transparency of these devices can potentially allow for their ubiquitous installation in glazing systems as part of nonintrusive BIPV elements or to power Internet of Things (IoT) devices and sensors as an integrated transparent component. Materials science ; Glazing ; Photovoltaic system ; Transmittance ; Optoelectronics ; Heterojunction ; Building-integrated photovoltaics ; Sputtering ; Band gap ; Photovoltaics ; Thin film ; Transparency (behavior) ; Absorption (acoustics) ; Optics ; Nanotechnology ; Composite material ; Electrical engineering ; Computer science ZnO doping and properties ; Perovskite Materials and Applications ; Transition Metal Oxide Nanomaterials
Authors: Rodrigo Galvão | Luiz Fernando dos Santos | Rogéria Rocha Gonçalves | Leonardo de S. Menezes
Source: Nano Select (article, 2020-11-24)
Field: Materials Science — Materials Chemistry

Fluorescence Intensity Ratio‐based temperature sensor with single Nd<sup>3 +</sup> :Y<sub>2</sub>O<sub>3</sub> nanoparticles: Experiment and theoretical modeling Abstract A thermometer based on single Nd 3 + :Y 2 O 3 nanoparticles is reported. The nanothermometer relies on the ratio of thermally coupled Nd 3 + emission lines accessible by either continuous‐wave upconversion under 880 nm or downconversion under 532 nm excitation wavelengths. Both processes are modeled through rate equation systems based on multiphonon interactions between excited luminescent states, which led to excellent agreement with the experimental data. Moreover, the Y 2 O 3 effective phonon mode energy was determined, showing the appropriateness of the theoretical approach used. The system presented a relative sensitivity up to 1.36% at 300 K while working within the first biological window, thus particularly useful for biological sensing applications. Excited state ; Photon upconversion ; Excitation ; Luminescence ; Fluorescence ; Wavelength ; Thermometer ; Nanoparticle ; Materials science ; Phonon ; Analytical Chemistry (journal) ; Atomic physics ; Optoelectronics ; Optics ; Physics ; Chemistry ; Nanotechnology ; Condensed matter physics ; Thermodynamics Luminescence Properties of Advanced Materials ; Optical properties and cooling technologies in crystalline materials ; Solid State Laser Technologies