jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Aaron E. Tallman | Krzysztof S. Stopka | Laura Swiler | Yan Wang | Surya R. Kalidindi | David L. McDowell
Source: JOM (article, 2019-06-07)
Field: Materials Science — Materials Chemistry

Gaussian-Process-Driven Adaptive Sampling for Reduced-Order Modeling of Texture Effects in Polycrystalline Alpha-Ti Calibration ; Homogenization (climate) ; Gaussian process ; Computer science ; Gaussian ; Process (computing) ; Experimental data ; Algorithm ; Data mining ; Mathematics ; Statistics ; Physics Machine Learning in Materials Science ; Titanium Alloys Microstructure and Properties ; X-ray Diffraction in Crystallography
Authors: Xiao‐Ying Yu | Bruce W. Arey | Sayandev Chatterjee | Jaehun Chun
Source: Surface and Interface Analysis (article, 2019-09-02)
Field: Materials Science — Surfaces, Coatings and Films

Improving in situ liquid SEM imaging of particles This work presents in situ imaging of synthesized boehmite (γ‐AlOOH) particles ranging from 20 to 100 nm, suspended in liquid, in a vacuum compatible microfluidic sample holder using a scanning electron microscopy (SEM) under the high vacuum mode and highlights the advantage of in situ liquid imaging of colloids. Nanometer‐sized boehmite particles in high‐level radioactive wastes at the Hanford site are known to be difficult to dissolve and cause rheological problems for processing in the nuclear waste treatment plant. Therefore, it is important to characterize boehmite particles and understand how they form aggregates in the liquid state. Several technical advancements are made to optimize in situ liquid SEM chemical imaging resulting in the improved ability to obtain secondary electron (SE), backscattered electron (BSE) images, and energy dispersive X‐ray spectroscopy (EDX) spectra. Moreover, our results show mixed particles could be studied and identified based on the particle shape and elemental composition using in situ SEM imaging and EDX. Thus, we provide a new and improved approach to observe the evolution of particle dispersion and stability in liquid under conditions similar to those in the waste tank. Boehmite ; Scanning electron microscope ; Materials science ; In situ ; Particle (ecology) ; Energy-dispersive X-ray spectroscopy ; Dispersion (optics) ; Nanoparticle ; Characterization (materials science) ; Spectroscopy ; Nanotechnology ; Analytical Chemistry (journal) ; Chemical engineering ; Optics ; Chemistry ; Composite material ; Chromatography ; Aluminium ; Physics Electron and X-Ray Spectroscopy Techniques ; Advanced Electron Microscopy Techniques and Applications ; Iron oxide chemistry and applications
Authors: Yu Liang | Lihua Zhang | Yukui Zhang
Source: Annual Review of Analytical Chemistry (article, 2019-04-02)
Field: Chemistry — Inorganic Chemistry

Well-Defined Materials for High-Performance Chromatographic Separation Chromatographic separation has been widely applied in various fields, such as chemical engineering, precision medicine, energy, and biology. Because chromatographic separation is based on differential partitioning between the mobile phase and stationary phase and affected by band dispersion and mass transfer resistance from these two phases, the materials used as the stationary phase play a decisive role in separation performance. In this review, we discuss the design of separation materials to achieve the separation with high efficiency and high resolution and highlight the well-defined materials with uniform pore structure and unique properties. The achievements, recent developments, challenges, and future trends of such materials are discussed. Furthermore, the surface functionalization of separation ma-terials for further improvement of separation performance is reviewed. Finally, future research directions and the challenges of chromatographic separation are presented. Separation (statistics) ; Chromatographic separation ; Stationary phase ; Chromatography ; Dispersion (optics) ; Materials science ; Phase (matter) ; Computer science ; Chemistry ; High-performance liquid chromatography ; Physics Metal-Organic Frameworks: Synthesis and Applications ; Nanopore and Nanochannel Transport Studies ; Analytical Chemistry and Chromatography
Authors: Yueliang Wang | Lingling Fang | Ming Gong | Zhaoxiang Deng
Source: Chemical Science (article, 2019-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Chemically modified nanofoci unifying plasmonics and catalysis A plasmonic nanofocus, often in the form of a nanogap, is capable of concentrating light in a nanometric volume. The greatly enhanced electromagnetic field offers many opportunities in physics and chemistry. However, the lack of a method to fine-tune the chemical activities of the nanofocus has severely limited its application. Here we communicate an intriguing class of chemically modified nanofoci (CMNFs) that are able to address this challenge. Our results successfully demonstrate a possibility to functionalize the nanosized, mass-transport-restricted nanogap (nanofocus) of a dimeric gold nanoparticle assembly with homo-(Au) and heterogeneous (Ag, Pt, and Pd) materials. The as-produced structures with conductive Au and Ag junctions generate a novel form of charge transfer plasmon (CTP) with continuously tunable frequency covering the visible and near-infrared domains. In addition, the Ag materials can be displaced by catalytic Pt and Pd metals while still maintaining a tightly focused electromagnetic field. These hybrid structures with unified catalytic and plasmonic properties enable real-time, on-site probing of catalytic conversions at the nanofocus by plasmon-enhanced Raman scattering. The chemically/optically engineered CMNFs represent the simplest function-integrated nanodevices for plasmonics, sensing, and catalysis. Our work not only realizes chemical CTP reshaping, but also allows chemical functionalization into an intensified plasmonic near-field. The latter may enable unconventional chemical reactions driven by the catalytically functionalized, strongly boosted light field. Plasmon ; Catalysis ; Nanotechnology ; Chemistry ; Combinatorial chemistry ; Materials science ; Organic chemistry ; Optoelectronics Gold and Silver Nanoparticles Synthesis and Applications ; Plasmonic and Surface Plasmon Research ; Copper-based nanomaterials and applications
Authors: Mitzy A. Penilla Garcia | Santosh K. Gupta | Yuanbing Mao
Source: Ceramics International (article, 2019-09-12)
Field: Materials Science — Materials Chemistry

Effects of molten-salt processing parameters on the structural and optical properties of preformed La2Zr2O7:Eu3+ nanoparticles Molten salt ; Materials science ; Crystallinity ; Salt (chemistry) ; Nanoparticle ; Particle size ; Chloride ; Particle (ecology) ; Chemical engineering ; Nanotechnology ; Metallurgy ; Composite material ; Chemistry ; Organic chemistry Nuclear materials and radiation effects ; Luminescence Properties of Advanced Materials ; Microwave Dielectric Ceramics Synthesis
Authors: Barry M. Trost | Zhijun Zuo
Source: Angewandte Chemie (article, 2019-10-14)
Field: Chemistry — Organic Chemistry

Highly Regio‐, Diastereo‐, and Enantioselective Synthesis of Tetrahydroazepines and Benzo[<i>b</i>]oxepines through Palladium‐Catalyzed [4+3] Cycloaddition Reactions Abstract A novel Pd 0 ‐catalyzed asymmetric [4+3] annulation reaction of two readily accessible starting materials has been developed for building seven‐membered heterocyclic architectures. The potential [3+2] side pathway could be suppressed though fine tuning of the conditions. A broad scope of cycloaddition donors and acceptors participated in the transformation with excellent chemo‐, regio‐, diastereo‐, and enantioselectivtities, leading to valuable tetrahydroazepines and benzo[ b ]oxepines. Cycloaddition ; Annulation ; Enantioselective synthesis ; Chemistry ; Palladium ; Catalysis ; Combinatorial chemistry ; Stereochemistry ; Organic chemistry Catalytic C–H Functionalization Methods ; Asymmetric Synthesis and Catalysis ; Catalytic Alkyne Reactions
Authors: Huacheng Zhang | Juhoon Lee | James T. Brewster | Xiaodong Chi | Vincent M. Lynch | Jonathan L. Sessler
Source: Journal of the American Chemical Society (article, 2019-02-27)
Field: Chemistry — Organic Chemistry

Cation-based Structural Tuning of Pyridine Dipyrrolate Cages and Morphological Control over Their Self-assembly Different pyridine dipyrrolate cages including cage-based dimers and polymers may be fabricated in a controlled manner from the same two starting materials, namely, an angular ligand 1 and Zn(acac)<sub>2</sub>, by changing the counter cation source. With tetrabutylammonium (TBA<sup>+</sup>) and dimethyl viologen (DMV<sup>2+</sup>), Cage-3 and Cage-5 are produced. In these cages, two ligands act as bridges and serve to connect together two cage subunits to produce higher order ensembles. In Cage-3 and Cage-5, the TBA<sup>+</sup> and DMV<sup>2+</sup> counter cations lie outside the cavities of the respective cages. This stands in contrast to what is seen with a previously reported system, Cage-1, wherein dimethylammonium (DMA<sup>+</sup>) counter cations reside within the cage cavity. When the counter cations are tetraethylammonium (TEA<sup>+</sup>) and bis(cyclopentadienyl) cobalt(III) (Cp<sub>2</sub>Co<sup>+</sup>), polymeric cage materials, PC-1 and PC-2, are formed, respectively. The counter cations thus serve not only to balance charge but also to tune the structural features as a whole. The organic cations used in the present study also act to modulate the further assembly of individual cages. The present cation-based tuning emerges as a new method for a fine-tuning of the multidimensional morphology of self-assembled inorganic materials. Chemistry ; Cage ; Pyridine ; Tetraethylammonium ; Ligand (biochemistry) ; Crystallography ; Stereochemistry ; Potassium ; Organic chemistry ; Receptor Supramolecular Chemistry and Complexes ; Porphyrin and Phthalocyanine Chemistry ; Molecular Sensors and Ion Detection
Authors: Gaoxiang Liu | Vikas Chauhan | Alexander P. Aydt | Sandra M. Ciborowski | Andrew Pinkard | Zhaoguo Zhu | Xavier Roy | Shiv N. Khanna | Kit H. Bowen
Source: The Journal of Physical Chemistry C (article, 2019-09-20)
Field: Materials Science — Materials Chemistry

Ligand Effect on the Electronic Structure of Cobalt Sulfide Clusters: A Combined Experimental and Theoretical Study Recent studies have shown that capping ligands offer a new dimension for fine-tuning the properties of clusters. Here we investigate this concept by measuring the anion photoelectron spectra of a series of hexanuclear cobalt sulfide clusters, Co6S8, passivated by different numbers of triethylphosphine ligands, PEt3. We find that the addition of PEt3 gradually shifts the electronic spectrum of the cluster to higher energy, leading to a decrease in its electron affinity. Density functional theory calculations reveal that adding ligands demagnetizes the Co6S8 core. The decrease in electron affinity results from a monotonic increase in the energy of the cluster lowest unoccupied molecular orbitals (LUMO). This effect is attributed to the electron donation from the ligands to the cluster core, which increases the charge density in the core region. Electron affinity (data page) ; Cluster (spacecraft) ; Binding energy ; Cobalt ; Chemistry ; Sulfide ; Density functional theory ; Atomic orbital ; Electronic structure ; Crystallography ; HOMO/LUMO ; Molecular orbital ; X-ray photoelectron spectroscopy ; Ligand (biochemistry) ; Physical chemistry ; Computational chemistry ; Chemical physics ; Electron ; Molecule ; Atomic physics ; Inorganic chemistry ; Physics ; Nuclear magnetic resonance ; Organic chemistry Nanocluster Synthesis and Applications ; Quantum Dots Synthesis And Properties ; Molecular Junctions and Nanostructures
Authors: Chiara Capitani | Valerio Pinchetti | Graziella Gariano | Beatriz Santiago González | Carlo Santambrogio | Marcello Campione | Mirko Prato | Rosaria Brescia | Andrea Camellini | Fulvio Bellato | Francesco Carulli | Abhinav Anand | M. Zavelani–Rossi | Francesco Meinardi | S. A. Crooker | Sergio Brovelli
Source: Nano Letters (article, 2019-01-21)
Field: Materials Science — Materials Chemistry

Quantized Electronic Doping towards Atomically Controlled “Charge-Engineered” Semiconductor Nanocrystals "Charge engineering" of semiconductor nanocrystals (NCs) through so-called electronic impurity doping is a long-standing challenge in colloidal chemistry and holds promise for ground-breaking advancements in many optoelectronic, photonic, and spin-based nanotechnologies. To date, our knowledge is limited to a few paradigmatic studies on a small number of model compounds and doping conditions, with important electronic dopants still unexplored in nanoscale systems. Equally importantly, fine-tuning of charge engineered NCs is hampered by the statistical limitations of traditional approaches. The resulting intrinsic doping inhomogeneity restricts fundamental studies to statistically averaged behaviors and complicates the realization of advanced device concepts based on their advantageous functionalities. Here we aim to address these issues by realizing the first example of II-VI NCs electronically doped with an exact number of heterovalent gold atoms, a known p-type acceptor impurity in bulk chalcogenides. Single-dopant accuracy across entire NC ensembles is obtained through a novel non-injection synthesis employing ligand-exchanged gold clusters as "quantized" dopant sources to seed the nucleation of CdSe NCs in organic media. Structural, spectroscopic, and magneto-optical investigations trace a comprehensive picture of the physical processes resulting from the exact doping level of the NCs. Gold atoms, doped here for the first time into II-VI NCs, are found to incorporate as nonmagnetic Au<sup>+</sup> species activating intense size-tunable intragap photoluminescence and artificially offsetting the hole occupancy of valence band states. Fundamentally, the transient conversion of Au<sup>+</sup> to paramagnetic Au<sup>2+</sup> (5d<sup>9</sup> configuration) under optical excitation results in strong photoinduced magnetism and diluted magnetic semiconductor behavior revealing the contribution of individual paramagnetic impurities to the macroscopic magnetism of the NCs. Altogether, our results demonstrate a new chemical approach toward NCs with physical functionalities tailored to the single impurity level and offer a versatile platform for future investigations and device exploitation of individual and collective impurity processes in quantum confined structures. Doping ; Semiconductor ; Materials science ; Nanocrystal ; Nanotechnology ; Charge (physics) ; Optoelectronics ; Physics ; Quantum mechanics Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films ; Gold and Silver Nanoparticles Synthesis and Applications
Authors: Jun Liu | Peiwen Xu | Pengcheng Wang | Zhijia Xu | Xinzhen Feng | Weijie Ji | Chak‐Tong Au
Source: Scientific Reports (article, 2019-11-18)
Field: Materials Science — Materials Chemistry

Vanadium Phosphorus Oxide/Siliceous Mesostructured Cellular Foams: efficient and selective for sustainable acrylic acid production via condensation route A new type of supported vanadium phosphorus oxide (VPO) with self-phase regulation was simply fabricated (organic solvent free) for the first time by depositing the specific VPO precursor NH<sub>4</sub>(VO<sub>2</sub>)HPO<sub>4</sub> onto the Siliceous Mesostructured Cellular Foams (MCF) with controlled activation. The resulting materials were found to be highly efficient and selective for sustainable acrylic acid (AA) plus methyl acrylate (MA) production via a condensation route between acetic acid (HAc) and formaldehyde (HCHO). A (AA + MA) yield of 83.7% (HCHO input-based) or a (AA + MA) selectivity of 81.7% (converted HAc-based) are achievable at 360 °C. The systematic characterizations and evaluations demonstrate a unique surface regulation occurring between the MCF and the NH<sub>4</sub>(VO<sub>2</sub>)HPO<sub>4</sub> precursor. NH<sub>3</sub> release upon activation of NH<sub>4</sub>(VO<sub>2</sub>)HPO<sub>4</sub> precursor together with adsorption of NH<sub>3</sub> by MCF automatically induces partial reduction of V<sup>5+</sup> whose content is fine-tunable by the VPO loading. Such a functionalization simultaneously modifies phase constitution and surface acidity/basicity of catalyst, hence readily controls catalytic performance. Catalysis ; Acrylic acid ; Vanadium ; Formaldehyde ; Acetic acid ; Vanadium oxide ; Chemistry ; Adsorption ; Inorganic chemistry ; Oxide ; Brønsted–Lowry acid–base theory ; Surface modification ; Solvent ; Phosphorus ; Selectivity ; Organic chemistry ; Polymer Polyoxometalates: Synthesis and Applications ; Catalysis and Hydrodesulfurization Studies ; Catalysis and Oxidation Reactions
Authors: Javier A. Gómez-Reguera | Eduardo Vivaldo‐Lima | Vida A. Gabriel | Marc A. Dubé
Source: Processes (article, 2019-06-26)
Field: Chemistry — Organic Chemistry

Modeling of the Free Radical Copolymerization Kinetics of n-Butyl Acrylate, Methyl Methacrylate and 2-Ethylhexyl Acrylate Using PREDICI® Kinetic modeling of the bulk free radical copolymerizations of n-butyl acrylate (BA) and 2-ethylhexyl acrylate (EHA); methyl methacrylate (MMA) and EHA; as well as BA, MMA and EHA was performed using the software PREDICI®. Predicted results of conversion versus time, composition versus conversion, and molecular weight development are compared against experimental data at different feed compositions. Diffusion-controlled effects and backbiting for BA were incorporated into the model as they proved to be significant in these polymerizations. The set of estimated global parameters allows one to assess the performance of these copolymerization systems over a wide range of monomer compositions. Acrylate ; Copolymer ; Methyl methacrylate ; Monomer ; Polymer chemistry ; Butyl acrylate ; Kinetics ; Methyl acrylate ; Materials science ; Methacrylate ; Polymer ; Composite material Advanced Polymer Synthesis and Characterization ; Photopolymerization techniques and applications ; Radioactive element chemistry and processing
Authors: Samir Farhat | M. Rekaby | R. Awad
Source: SN Applied Sciences (article, 2019-05-11)
Field: Materials Science — Materials Chemistry

Vickers microhardness and indentation creep studies for erbium-doped ZnO nanoparticles Materials science ; Indentation hardness ; Indentation ; Creep ; Composite material ; Vickers hardness test ; Dislocation ; Dwell time ; Doping ; Metallurgy ; Microstructure ; Optoelectronics ZnO doping and properties ; Metal and Thin Film Mechanics ; Acoustic Wave Resonator Technologies
Authors: Xiaolong Huang | Jun Wan | Dewen Leng | Yingying Zhang | Shuo Yang
Source: Experimental and Therapeutic Medicine (article, 2019-11-19)
Field: Materials Science — Biomaterials

Dual‑targeting nanomicelles with CD133 and CD44 aptamers for enhanced delivery of gefitinib to two populations of lung cancer‑initiating cells Lung cancer is an aggressive type of cancer that is associated with a high mortality rate. Lung cancer-initiating cells are populations of self-renewing cancer cells with pluripotent differentiation ability. Cancers typically originate from multiple phenotypically distinct cancer-initiating cells. CD133 and CD44 are specific markers that maybe used to distinguish lung cancer-initiating cells. The ability to target a variety of subsets of cancer-initiating cells instead of targeting only one population of cancer initiating-cells has the potential to increase the cancer therapeutic efficacy. In the present study, CD133 and CD44 aptamer-conjugated nanomicelles loaded with gefitinib (CD133/CD44-NM-Gef) were developed to target CD133<sup>+</sup> and CD44<sup>+</sup> lung cancer-initiating cells. The therapeutic efficacy of CD133/CD44-NM-Gef against lung cancer-initiating cells was assessed by evaluating cell proliferation, tumorsphere formation and detection of CD44<sup>+</sup> and CD133<sup>+</sup> cells using flow cytometry. The results indicated that CD133/CD44-NM-Gef targeted CD133<sup>+</sup> and CD44<sup>+</sup> lung cancer-initiating cells and exhibited greater therapeutic efficacy against lung cancer-initiating cells than single-target and non-targeted nanomicelles, suggesting that CD133/CD44-NM-Gef represents a promising treatment for lung cancer by specifically targeting lung cancer-initiating cells. To the best of our knowledge, the present study was the first to report on drug delivery via nanomedicines targeted to multiple populations of cancer-initiating cells using aptamers. As cancer is typically derived from phenotypically distinct cancer-initiating cells, the nanomicelle-based multiple targeting strategy provided is promising for targeting multiple subsets of cancer-initiating cell within a tumor. Gefitinib ; Aptamer ; Oncogene ; Molecular medicine ; Lung cancer ; CD44 ; Cancer ; Cancer research ; Medicine ; Cell cycle ; Biology ; Cell ; Oncology ; Molecular biology ; Internal medicine ; Epidermal growth factor receptor ; Genetics Nanoparticle-Based Drug Delivery ; Advanced biosensing and bioanalysis techniques ; RNA Interference and Gene Delivery
Authors: Pavel Mach | Attila Géczy | Radek Polanský | David Bušek
Source: Journal of Materials Science Materials in Electronics (article, 2019-02-12)
Field: Materials Science — Materials Chemistry

Glass transition temperature of nanoparticle-enhanced and environmentally stressed conductive adhesive materials for electronics assembly In our paper, the characterization of glass transition temperature (Tg) was performed for one- and two-component electrically conductive adhesive used in electronic joining technologies. Both adhesives were of the epoxy type with the silver filler. Dynamic mechanical analysis (DMA) was used to measure the Tg. The adhesives were modified with nanoparticles, namely, carbon nanotubes (concentration of 0.5 and 0.8% by weight) and silver nanoballs (2.5% by weight). The values of Tg were determined from the plot of the Tg δ parameter. Two types of environmental stresses were used for climatic aging: 125 °C/56% RH and 85 °C/85% RH. The aging of the samples at 125 °C and 56% RH caused increase Tg for all formulations. The cause of these changes is additional curing of adhesive. Aging in the combined climate 85 °C/85% RH caused a shift in Tg toward lower values for formulations based on the one-component adhesive modified by CNT and toward higher values for all other formulations. The major cause of the decrease in Tg was that CNT inhered the curing reactions and banned them from completion. In cases where Tg grew, glue hardening take place. DMA was performed to examine Tg of the samples. The DMA measurements were carried out up to 200 °C. Repeated DMA measurement confirmed that this measurement caused additional hardening and increase Tg for all samples. The results will contribute to the use of conductive adhesives with better quality and reliability in electronics manufacturing. Adhesive ; Materials science ; Glass transition ; Curing (chemistry) ; Composite material ; Dynamic mechanical analysis ; Epoxy ; Hardening (computing) ; Carbon nanotube ; Nanoparticle ; Electrical conductor ; Polymer ; Nanotechnology Carbon Nanotubes in Composites ; Electronic Packaging and Soldering Technologies ; Advanced Sensor and Energy Harvesting Materials