jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Xuekang Cai | Jia Zhang | Jiaqi Lu | Long Yi | Zheng Han | Shuixing Zhang | Xing Yang | Guanshu Liu
Source: Chemistry - A European Journal (article, 2020-07-08)
Field: Materials Science — Materials Chemistry

<i>N</i>‐Aryl Amides as Chemical Exchange Saturation Transfer Magnetic Resonance Imaging Contrast Agents Chemical exchange saturation transfer (CEST) MRI has recently emerged as a versatile molecular imaging approach in which diamagnetic compounds can be utilized to generate an MRI signal. To expand the scope of CEST MRI applications, herein, we systematically investigated the CEST properties of N-aryl amides with different N-aromatic substitution, revealing their chemical shifts (4.6-5.8 ppm) and exchange rates (up to thousands s<sup>-1</sup> ) are favorable to be used as CEST agents as compared to alkyl amides. As the first proof-of-concept study, we used CEST MRI to detect the enzymatic metabolism of the drug acebutolol directly by its intrinsic CEST signal without any chemical labeling. Our study implies that N-aryl amides may enable the label-free CEST MRI detection of the metabolism of many N-aryl amide-containing drugs and a variety of enzymes that act on N-aryl amides, greatly expanding the scope of CEST MR molecular imaging. Chemistry ; Amide ; Aryl ; Nuclear magnetic resonance ; Magnetic resonance imaging ; Chemical shift ; Relaxometry ; Alkyl ; Organic chemistry ; Physical chemistry Lanthanide and Transition Metal Complexes ; Advanced MRI Techniques and Applications ; Magnetism in coordination complexes
Authors: Yuxin Li | Collin M. Fleischer | Ashley E. Ross
Source: Chemical Communications (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

High Young's modulus carbon fibers are fouling resistant with fast-scan cyclic voltammetry We report evidence that high Young's modulus carbon-fibers resist detrimental chemical fouling at their surface similarly to carbon nanotube fibers with fast-scan cyclic voltammetry. This provides a new method for stable monitoring of neurochemicals like serotonin, without the need to purchase costly carbon nanotube microfibers or perform complicated electrode immobilizations. Cyclic voltammetry ; Modulus ; Fouling ; Materials science ; Carbon fibers ; Composite material ; Chemical engineering ; Chemistry ; Electrode ; Electrochemistry ; Membrane ; Physical chemistry ; Composite number Graphene research and applications ; Supercapacitor Materials and Fabrication ; Fiber-reinforced polymer composites
Authors: Thomas Delouche | Antoine Vacher | Thierry Roisnel | Marie Cordier≈ | Jean‐Frédéric Audibert | Boris Le Guennic | Fabien Miomandre | Denis Jacquemin | Muriel Hissler | Pierre‐Antoine Bouit
Source: Materials Advances (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Luminescent molecular switches based on dicationic P-doped polycyclic aromatic hydrocarbons We report the efficient synthesis cationic P-doped Polycyclic Aromatic Hydrocarbons showing electrofluorochromic properties. Cationic polymerization ; Polycyclic aromatic hydrocarbon ; Chemistry ; Luminescence ; Photochemistry ; Hydrocarbon ; Doping ; Organic chemistry ; Materials science ; Optoelectronics Synthesis and Properties of Aromatic Compounds ; Luminescence and Fluorescent Materials ; Porphyrin and Phthalocyanine Chemistry
Authors: Joe I. Higham | James A. Bull
Source: Chemical Communications (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Copper catalysed oxidative α-sulfonylation of branched aldehydes using the acid enhanced reactivity of manganese(<scp>iv</scp>) oxide The oxidative coupling of secondary aldehydes and sulfinate salts is achieved using copper catalysis to form α-sulfonyl aldehydes. The use of an acidic co-solvent is important to adjust the oxidation potential of MnO2 as an oxidant. A broad range of sulfonylated aldehydes is prepared, and their further functionalisation is demonstrated. A dual ionic/radical pathway mechanism is proposed. Manganese ; Chemistry ; Reactivity (psychology) ; Manganese oxide ; Oxidative phosphorylation ; Copper ; Oxide ; Organic chemistry ; Catalysis ; Biochemistry Sulfur-Based Synthesis Techniques ; Chemical Synthesis and Reactions ; Catalytic C–H Functionalization Methods
Authors: Rabiatuladawiyah Md Akhir | Siti Zulaikha Umbaidilah | Nurul Afaah Abdullah | Salman Alrokayan | Haseeb A. Khan | Tetsuo Soga | M. Rusop | Z. Khusaimi
Source: Micromachines (article, 2020-03-13)
Field: Materials Science — Materials Chemistry

The Potential of Pandanus amaryllifolius Leaves Extract in Fabrication of Dense and Uniform ZnO Microrods Zinc oxide (ZnO) micro and nanorods were successfully prepared using <i>Pandanus amaryllifolius</i> and hexamethylenetetramine (HMTA) separately as stabilizers using the solution immersion method. Two types of ZnO seed layer were prepared using the same pre-cursor with the different stabilizers. The fabricated ZnO microrods exhibit absorption at ~375 nm as revealed from the UV-Visible absorption spectrum, and this is comparable with ZnO nanorods synthesized using HMTA. X-ray diffraction (XRD) measurement displayed a sharp peak corresponding to the hexagonal wurtzite structure of ZnO microrods. Field emission scanning electron microscopy (FESEM) of ZnO microrods showed average diameter at approximately 500 nm compared to 70 nm of those synthesized from HMTA. A new finding is the ability of <i>Pandanus amaryllifolius</i> as a green stabilizer to grow a dense ZnO microrod structure with high crystallinity. Results reveal that both samples from different stabilizers during the preparation of the ZnO seed layer greatly improved the morphological and structural properties and optical absorption of ZnO. The main outcomes from this study will benefit optoelectronic application, such as in ultraviolet (UV) sensors. Wurtzite crystal structure ; Nanorod ; Hexamethylenetetramine ; Materials science ; Crystallinity ; Zinc ; Absorption (acoustics) ; Scanning electron microscope ; Fabrication ; Chemical engineering ; Nanotechnology ; Optoelectronics ; Composite material ; Metallurgy ZnO doping and properties ; Nanoparticles: synthesis and applications ; Polymer Nanocomposite Synthesis and Irradiation
Authors: Prerna Yadav | Felix Zelder
Source: CHIMIA International Journal for Chemistry (review, 2020-04-25)
Field: Materials Science — Materials Chemistry

Metal-Salen-based Probes for the Selective Detection of Phosphates via a Disassembly Approach Polyoxophosphates are ubiquitous in nature and play important roles in biological systems and in the environment. Pyrophosphate (PPi), an important member of this family, is produced in over 200 biochemical reactions and is a marker in clinical diagnosis. In addition to its endogenous role, PPi alias E450 is currently used as preservative, emulsifier or taste intensifier in foodstuff. Despite this widespread occurrence and biological importance, it is rather surprising that robust chemical systems that detect selectively and sensitively PPi in challenging matrices are still lacking. This mini review focuses on metal-salen complexes as reaction-based fluorescent sensors for the selective detection of PPi and other phosphates. The mode of detection is based on a novel disassembly approach in which the metal ion is sequestered by the target analyte from the complex and the metal-free ligand hydrolyses spontaneously into its fluorescent subunits. Optimizations of the probe and applications for PPi detection in cells and foodstuff are described. Pyrophosphate ; Analyte ; Chemistry ; Fluorescence ; Combinatorial chemistry ; Metal ; Metal ions in aqueous solution ; Biochemistry ; Chromatography ; Enzyme ; Organic chemistry Polyoxometalates: Synthesis and Applications ; Molecular Sensors and Ion Detection ; biodegradable polymer synthesis and properties
Authors: Sungjun In | Jin-Cheol Cho | Jusung Park | So Yeun Kim | Hyun-Tak Kim | Tae Won Noh | Namkyoo Park
Source: Advanced Photonics Research (article, 2020-09-03)
Field: Materials Science — Polymers and Plastics

Self‐Organized Gold Network–Vanadium Dioxide Hybrid Film for Dynamic Modulation of Visible‐to‐Near‐Infrared Light Composites of phase change material (PCM) and structured metal (SM) are promising templates for photonic applications combining advantages of both insulator–metal transition (IMT) hysteresis and strong light–matter interactions. While significant progress has been made for applications including active modulators, photonic memories, and thermal emitters in the THz‐microwave regime, the fabrication and application of PCM–SM for the visible–near‐infrared (vis–NIR) waves are still limited by the difficulties associated with fabricating nanostructures in a controllable and scalable manner. Herein, a self‐organized gold network–vanadium dioxide hybrid film fabricated by a simple spin‐coating process following the metal deposition, as a litho‐free PCM–SM template in a vis–NIR regime, is demonstrated. Using Fabry–Perot‐type interference, which enhances IMT‐induced refractive index changes, resonance shift of as much as 260 nm and reflection modulation depth of ≈49% in vis–NIR range are then demonstrated. Tuning of the resonance peak from 575 to 950 nm with the control of VO 2 thickness, in addition to the manipulation of hysteresis characteristics with the control of self‐organized gold network is also demonstrated. As application examples, thermoactive color film and electrically controlled photonic logic gates in vis–NIR are presented. Materials science ; Optoelectronics ; Photonics ; Visible spectrum ; Nanotechnology ; Near-infrared spectroscopy ; Optics Transition Metal Oxide Nanomaterials ; Metamaterials and Metasurfaces Applications ; Phase-change materials and chalcogenides
Authors: A.V. Nikitin | A.A. Rodina | Xavier Thomas | L. Manceron | L. Daumont | M. Rey | Keeyoon Sung | A. E. Protasevich | S.A. Tashkun | Iana S. Chizhmakova | Vladimir G. Tyuterev
Source: Journal of Quantitative Spectroscopy and Radiative Transfer (article, 2020-06-08)
Field: Chemistry — Spectroscopy

Line list of 12CH4 in the 4300–4600 cm−1 region Spectral line ; Ab initio ; Line (geometry) ; HITRAN ; Hamiltonian (control theory) ; Quantum number ; Dipole ; Physics ; Chemistry ; Atomic physics ; Mathematics ; Geometry ; Quantum mechanics Spectroscopy and Laser Applications ; Atmospheric Ozone and Climate ; Advanced Chemical Physics Studies
Authors: Alessandro Difalco | Francesco Aversano | Stefano Boldrini | A. Ferrario | Marcello Baricco | Alberto Castellero
Source: Metals (article, 2020-05-11)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Synthesis and Characterization of Thermoelectric Co2XSn (X = Zr, Hf) Heusler Alloys In this work, we report the results of an experimental investigation on the synthesis, structure, microstructure, mechanical, electrical conductivity, and Seebeck coefficient of Co2XSn (X = Zr, Hf) alloys. In both the alloys, the main constituent is a full Heusler-type compound that coexists with small amounts of secondary phases. Both alloys show a rather high Vickers hardness (around 900 HV) and an indentation fracture toughness typical of ceramics (around 2 MPa·m1/2). The electronic transport properties of the two alloys were measured for the first time. The temperature dependence of both the Seebeck coefficient and the electrical conductivity of the two alloys shows a change in correspondence of the Curie temperature. The Seebeck coefficient reaches a constant plateau, while the electrical conductivities show a transition from metallic to semiconductor behavior. As a consequence, almost constant values of the power factor have been obtained for the power factor above the Curie temperature, which is promising for an efficient exploitation of thermal gradients of several hundreds of degree in waste heat harvesting applications. Finally, on the basis of results from this work and from the literature, the effect of the substitution of the X element on the electronic transport properties in the series Co2XSn (X = Ti, Zr, Hf) is discussed. Seebeck coefficient ; Materials science ; Curie temperature ; Electrical resistivity and conductivity ; Thermoelectric effect ; Condensed matter physics ; Microstructure ; Thermoelectric materials ; Fracture toughness ; Vickers hardness test ; Thermal conductivity ; Metallurgy ; Composite material ; Thermodynamics ; Ferromagnetism Heusler alloys: electronic and magnetic properties ; Advanced Thermoelectric Materials and Devices ; MXene and MAX Phase Materials
Authors: Viktor S. Stroylov | Maria V. Panova | Filip V. Toukach
Source: International Journal of Molecular Sciences (article, 2020-10-15)
Field: Materials Science — Materials Chemistry

Comparison of Methods for Bulk Automated Simulation of Glycosidic Bond Conformations Six empirical force fields were tested for applicability to calculations for automated carbohydrate database filling. They were probed on eleven disaccharide molecules containing representative structural features from widespread classes of carbohydrates. The accuracy of each method was queried by predictions of nuclear Overhauser effects (NOEs) from conformational ensembles obtained from 50 to 100 ns molecular dynamics (MD) trajectories and their comparison to the published experimental data. Using various ranking schemes, it was concluded that explicit solvent MM3 MD yielded non-inferior NOE accuracy with newer GLYCAM-06, and ultimately PBE0-D3/def2-TZVP (Triple-Zeta Valence Polarized) Density Functional Theory (DFT) simulations. For seven of eleven molecules, at least one empirical force field with explicit solvent outperformed DFT in NOE prediction. The aggregate of characteristics (accuracy, speed, and compatibility) made MM3 dynamics with explicit solvent at 300 K the most favorable method for bulk generation of disaccharide conformation maps for massive database filling. Molecular dynamics ; Chemistry ; Force field (fiction) ; Glycosidic bond ; Computational chemistry ; Disaccharide ; Density functional theory ; Molecule ; Nuclear Overhauser effect ; Valence (chemistry) ; Stereochemistry ; Computer science ; Organic chemistry ; Artificial intelligence Enzyme Structure and Function ; Protein Structure and Dynamics ; Molecular spectroscopy and chirality
Authors: Andrew Rosen | Shaelyn Iyer | Debmalya Ray | Zhenpeng Yao | Alán Aspuru‐Guzik | Laura Gagliardi | Justin M. Notestein | Randall Q. Snurr
Source: ChemRxiv (preprint, 2020-10-29)
Field: Materials Science — Materials Chemistry

Machine Learning the Quantum-Chemical Properties of Metal–Organic Frameworks for Accelerated Materials Discovery with a New Electronic Structure Database &lt;p&gt;Metal–organic frameworks (MOFs) are a widely investigated class of crystalline solids with tunable structures that make it possible to impart specific chemical functionality tailored for a given application. However, the enormous number of possible MOFs that can be synthesized makes it difficult to determine which materials would be the most promising candidates, especially for applications governed by electronic structure properties that are often computationally demanding to simulate and time-consuming to probe experimentally. Here, we have developed the first publicly available quantum-chemical database for MOFs (the “QMOF database”), which consists of properties derived from density functional theory (DFT) for over 14,000 experimentally synthesized MOFs. Throughout this study, we demonstrate how this new database can be used to identify MOFs with targeted electronic structure properties. As a proof-of-concept, we use the QMOF database to evaluate the performance of several machine learning models for the prediction of DFT-computed band gaps and find that crystal graph convolutional neural networks are capable of achieving superior predictive performance, making it possible to circumvent computationally expensive quantum-chemical calculations. We also show how unsupervised learning methods can aid the discovery of otherwise subtle structure–property relationships using the computational findings in this work. We conclude by highlighting several MOFs with low band gaps, a challenging task given the electronically insulating nature of most MOF structures. The data and predictive models generated in this work, as well as the database of MOF structures, should be highly useful to other researchers interested in the predictive design and discovery of MOFs for the many applications dictated by quantum-chemical phenomena.&lt;br&gt;&lt;/p&gt; Computer science ; Quantum chemical ; Property (philosophy) ; Density functional theory ; Convolutional neural network ; Electronic structure ; Chemical database ; Metal-organic framework ; Database ; Machine learning ; Artificial intelligence ; Molecule ; Chemistry ; Computational chemistry Machine Learning in Materials Science ; Metal-Organic Frameworks: Synthesis and Applications ; X-ray Diffraction in Crystallography
Authors: Melodie Christensen | Lars P. E. Yunker | Folarin Adedeji | Florian Häse | Loı̈c M. Roch | Tobias Gensch | Gabriel dos Passos Gomes | Tara Zepel | Matthew S. Sigman | Alán Aspuru‐Guzik | Jason E. Hein
Source: ChemRxiv (preprint, 2020-11-03)
Field: Materials Science — Materials Chemistry

Data-science driven autonomous process optimization Autonomous process optimization involves the human intervention-free exploration of a range of pre-defined process parameters in order to improve responses such as reaction yield and product selectivity. Utilizing off-the-shelf components, we developed a closed-loop system capable of carrying out parallel autonomous process optimization experiments in batch with significantly reduced cycle times. Upon implementation of our system in the autonomous optimization of a palladium-catalyzed stereoselective Suzuki-Miyaura coupling, we found that the definition of a set of meaningful, broad, and unbiased process parameters was the most critical aspect of a successful optimization. In addition, we found that categorical parameters such as phosphine ligand were vital to determining the reaction outcome. To date, categorical parameter selection has relied on chemical intuition, potentially introducing an element of bias into the experimental design. In seeking a systematic method for the selection of a diverse set of phosphine ligands fully representative of the chemical space, we developed a strategy that leveraged computed molecular descriptor clustering analysis. This strategy allowed for the successful autonomous optimization of a stereoselective Suzuki-Miyaura coupling between a vinyl sulfonate and an arylboronic acid to selectively generate the E-product isomer in high yield. Categorical variable ; Computer science ; Process optimization ; Mathematical optimization ; Biochemical engineering ; Mathematics ; Machine learning ; Engineering Machine Learning in Materials Science ; Innovative Microfluidic and Catalytic Techniques Innovation ; Gene expression and cancer classification
Authors: Kristof Toth | Chinedum O. Osuji | Kevin G. Yager | Gregory S. Doerk
Source: RSC Advances (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

High-throughput morphology mapping of self-assembling ternary polymer blends Multicomponent blending is a convenient yet powerful approach to rationally control the material structure, morphology, and functional properties in solution-deposited films of block copolymers and other self-assembling nanomaterials. However, progress in understanding the structural and morphological dependencies on blend composition is hampered by the time and labor required to synthesize and characterize a large number of discrete samples. Here, we report a new method to systematically explore a wide composition space in ternary blends. Specifically, the blend composition space is divided into gradient segments deposited sequentially on a single wafer by a new gradient electrospray deposition tool, and characterized using high-throughput grazing-incidence small-angle X-ray scattering. This method is applied to the creation of a ternary morphology diagram for a cylinder-forming polystyrene-<i>block</i>-poly(methyl methacrylate) (PS-<i>b</i>-PMMA) block copolymer blended with PS and PMMA homopolymers. Using "wet brush" homopolymers of very low molecular weight (∼1 kg mol<sup>-1</sup>), we identify well-demarcated composition regions comprising highly ordered cylinder, lamellae, and sphere morphologies, as well as a disordered phase at high homopolymer mass fractions. The exquisite granularity afforded by this approach also helps to uncover systematic dependencies among self-assembled morphology, topological grain size, and domain period as functions of homopolymer mass fraction and PS : PMMA ratio. These results highlight the significant advantages afforded by blending low molecular weight homopolymers for block copolymer self-assembly. Meanwhile, the high-throughput, combinatorial approach to investigating nanomaterial blends introduced here dramatically reduces the time required to explore complex process parameter spaces and is a natural complement to recent advances in autonomous X-ray characterization. Ternary operation ; Morphology (biology) ; Materials science ; Polymer ; Throughput ; Chemical engineering ; Polymer science ; Nanotechnology ; Composite material ; Computer science ; Engineering ; Geology Block Copolymer Self-Assembly ; Advanced Polymer Synthesis and Characterization ; Machine Learning in Materials Science
Authors: M. Bakayoko | J. Sackey | L.C. Razanamahandry | B.D. Ngom | Seteno Karabo Obed Ntwampe
Source: Materials Today Proceedings (article, 2020-06-09)
Field: Materials Science — Materials Chemistry

Bio-synthesis and characterization of nanoscaled CdO using corn husk extract via green nano-chemistry Cadmium oxide ; Absorbance ; Fourier transform infrared spectroscopy ; Scanning electron microscope ; Nanoparticle ; Spectroscopy ; Materials science ; Raman spectroscopy ; Attenuated total reflection ; Nuclear chemistry ; Husk ; Analytical Chemistry (journal) ; Energy-dispersive X-ray spectroscopy ; Photoluminescence ; Chemical engineering ; Nanotechnology ; Chemistry ; Cadmium ; Organic chemistry ; Chromatography ; Optics ; Metallurgy ; Optoelectronics ; Composite material Nanoparticles: synthesis and applications ; Graphene and Nanomaterials Applications ; Copper-based nanomaterials and applications
Authors: Işıl Sanrı Karapınar | Ahmet Onur Pehlivan | Selcan Karakuş | Ayşe Elif Özsoy Özbay | Ahmet Utku Yazgan | Nevin Taşaltın | Ayben Kilislioğlu
Source: Materiales de Construcción (article, 2020-11-03)
Field: Materials Science — Materials Chemistry

Application of novel synthesized nanocomposites containing κ-carrageenan/PVA/eggshell in cement mortars This study is a preliminary attempt to present the preparation and the first time a κ-carrageenan/PVA/eggshell nanostructure is used as a novel biodegradable and homogeneous nanostructure in cement composition. In order to clearly understand the effects these additives have on the mechanical properties of cementitious composites, they were synthesized in double and triple combinations and added into mortar mixtures. Three different cement mortar specimens were prepared by integrating the additives in ratios of 0, 0.1, 0.5 and 1% by cement weight and flexural and compressive strengths of the specimens were determined at the ages of 7 and 28 days. The flowability of the presented nanostructures was also discussed. The results revealed a 10–11% increase in both compressive and flexural strengths for the specimens prepared with the triple combination of the proposed additives. Moreover, strain capacity was enhanced as a result of the efficient dispersion of additives in the cement matrix. Materials science ; Cement ; Composite material ; Flexural strength ; Mortar ; Cementitious ; Nanocomposite ; Compressive strength Magnesium Oxide Properties and Applications ; Bone Tissue Engineering Materials ; Calcium Carbonate Crystallization and Inhibition