jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Tárcius N. Ramos | Sylvio Canuto | Benoı̂t Champagne
Source: Journal of Chemical Information and Modeling (article, 2020-04-13)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Unraveling the Electric Field-Induced Second Harmonic Generation Responses of Stilbazolium Ion Pairs Complexes in Solution Using a Multiscale Simulation Method The electric field-induced second harmonic generation (EFISHG) response has been largely used to describe the first β and the second γ hyperpolarizabilities in solution. Although the EFISHG technique cannot be applied to charged compounds (due to the external static electric field), it can be used to describe ion pairs as neutral complexes. A multiscale computational approach is required to generate representative geometrical configurations of such kinds of complexes (using classical force fields), to compute the electronic structure of each configuration (using quantum mechanics methods), and to perform statistical analyses describing the behavior of the nonlinear optical properties. In this work, we target solvated neutral ion pairs complexes, of which the cation is an organic chromophore, and we estimate their EFISHG and hyper-Rayleigh scattering responses. It is shown that the anion-cation relative spatial distribution determines the permanent dipole moment of the complexes, and therefore the relative distance controls the EFISHG response. On the other hand, the β tensor is independent of the dipole moment and it shows a weak linear correlation with the π-electron conjugation length of the cations. The γ contributions in the global EFISHG response range from 5% to 15%, which is mostly due to the variations of amplitude of the μβ<sub>∥</sub> contribution, which results from differences in the μ and β vectors' orientations. The applied multiscale approach provides reasonable results compared with experimental ones, although additional efforts are still required to improve such comparison mainly to consider the possible dissociation effects. Dipole ; Chromophore ; Ion ; Chemistry ; Electric field ; Electric dipole moment ; Second-harmonic generation ; Molecular physics ; Nonlinear system ; Chemical physics ; Quantum ; Moment (physics) ; Amplitude ; Harmonic ; Work (physics) ; Dissociation (chemistry) ; Computational chemistry ; Physics ; Classical mechanics ; Quantum mechanics ; Physical chemistry ; Photochemistry Nonlinear Optical Materials Research ; Photochemistry and Electron Transfer Studies ; Spectroscopy and Quantum Chemical Studies
Authors: Anna Jagusiak | Jakub Goclon | Tomasz Pańczyk
Source: Applied Surface Science (article, 2020-10-26)
Field: Materials Science — Materials Chemistry

Adsorption of Evans blue and Congo red on carbon nanotubes and its influence on the fracture parameters of defective and functionalized carbon nanotubes studied using computational methods This work addresses the problem of the modification of mechanical parameters of carbon nanotubes as a result of Congo red and Evans blue adsorption, functionalization of the nanotubes surfaces by carboxyl groups and generation of surface defects. The studies were also focused on the quantum chemical analysis of the effects of Evans blue adsorption on the properties of the nanotubes. We found that Evans blue is rather physisorbed than chemisorbed and it does not significantly affect the electronic state of the nanotubes. The molecular dynamics studies led to the conclusion that the nanotube chirality affects the fracture parameters substantially but the presence of the adsorbed Congo red/Evans blue mixture has only minor effect for the zigzag nanotubes. The effect is slightly bigger for the defective armchair nanotubes and significant fluctuations of the failure strain was observed. However, non defective armchair ones are also not sensitive to the adsorption of dyes. The presence of surface functionalization was generally found as negligible. The only exception were defective armchair nanotubes for which small changes (±5%) were found for the carboxylated nanotubes. Carbon nanotube ; Congo red ; Adsorption ; Surface modification ; Materials science ; Zigzag ; Selective chemistry of single-walled nanotubes ; Chirality (physics) ; Nanotube ; Nanotechnology ; Optical properties of carbon nanotubes ; Chemical engineering ; Chemistry ; Organic chemistry Carbon Nanotubes in Composites ; Graphene research and applications ; Nanotechnology research and applications
Authors: Sahar Foroughirad | Vahid Haddadi‐Asl | Alireza Khosravi | Mehdi Salami‐Kalajahi
Source: Polymers for Advanced Technologies (article, 2020-10-25)
Field: Chemistry — Analytical Chemistry

Magnetic halloysite‐<scp>based molecularly</scp> imprinted polymer for specific recognition of sunset yellow in dyes mixture Novel magnetic halloysite‐based molecularly imprinted polymer (MMIP) is fabricated for sunset yellow dye removal from water solution. Field emission scanning electron microscopy, vibrating sample magnetometer, Zeta potential test, thermogravimetric, and nitrogen gas adsorption analysis were all employed for characterizations of the obtained magnetic halloysite and the final adsorbent. Transmission electron microscope images proved the synthesis of polymeric shell onto the magnetic nanotubes with the thickness of 10 nm. The adsorption kinetics were assessed by pseudo‐first order, pseudo‐second order, and intraparticle diffusion models and the results revealed that the obtained MMIP adsorption procedure would be controlled by chemical adsorption due to the high correlation coefficient (R 2 ≥ 0.99) achieved for pseudo‐second order model. The effect of dye initial concentration was observed on the pseudo‐second order rate constant and the final equilibrium capacity of the MMIP. The adsorption isotherm at different temperatures (30 and 60°C) was assessed by two popular models, Langmuir and Freundlich. The resulting data were well fitted by Langmuir isotherm model, suggesting that the monolayer adsorption of sunset yellow onto the MMIP would occur. The exothermic behavior of the adsorption was justified by determining the effect of temperature on the Langmuir isotherm constant. The fabricated MMIP represented high adsorption capacity and imprinting factor of 46.43 μmol/g and 1.33, respectively. Moreover, the high selective recognition ability toward sunset yellow was observed for MMIP in the dyes mixture solution. Adsorption ; Thermogravimetric analysis ; Langmuir adsorption model ; Halloysite ; Freundlich equation ; Langmuir ; Materials science ; Molecularly imprinted polymer ; Analytical Chemistry (journal) ; Nuclear chemistry ; Chemistry ; Chromatography ; Organic chemistry ; Composite material ; Selectivity Dye analysis and toxicity ; Biochemical Analysis and Sensing Techniques ; melanin and skin pigmentation
Authors: Godwill Mbiti Kanyolo | Titus Masese
Source: Scientific Reports (article, 2020-08-06)
Field: Materials Science — Materials Chemistry

An idealised approach of geometry and topology to the diffusion of cations in honeycomb layered oxide frameworks Honeycomb layered oxides are a novel class of nanostructured materials comprising alkali or coinage metal atoms intercalated into transition metal slabs. The intricate honeycomb architecture and layered framework endows this family of oxides with a tessellation of features such as exquisite electrochemistry, unique topology and fascinating electromagnetic phenomena. Despite having innumerable functionalities, these materials remain highly underutilised as their underlying atomistic mechanisms are vastly unexplored. Therefore, in a bid to provide a more in-depth perspective, we propose an idealised diffusion model of the charged alkali cations (such as lithium, sodium or potassium) in the two-dimensional (2D) honeycomb layers within the multi-layered crystal of honeycomb layered oxide frameworks. This model not only explains the correlation between the excitation of cationic vacancies (by applied electromagnetic fields) and the Gaussian curvature deformation of the 2D surface, but also takes into consideration, the quantum properties of the cations and their inter-layer mixing through quantum tunnelling. Through this work, we offer a novel theoretical framework for the study of multi-layered materials with 2D cationic diffusion currents, as well as providing pedagogical insights into the role of topological phase transitions in these materials in relation to Brownian motion and quantum geometry. Honeycomb ; Cationic polymerization ; Topology (electrical circuits) ; Diffusion ; Oxide ; Gaussian curvature ; Curvature ; Honeycomb structure ; Phase transition Electronic and Structural Properties of Oxides ; Topological Materials and Phenomena ; Anodic Oxide Films and Nanostructures
Authors: Fang-Bor Weng | Mangaliso Menzi Dlamini | Guo‐Bin Jung | Chuan-Xing Lian
Source: International Journal of Hydrogen Energy (article, 2020-03-20)
Field: Materials Science — Materials Chemistry

Analyses of reversible solid oxide cells porosity effects on temperature reduction Porosity ; Multiphysics ; Materials science ; Knudsen diffusion ; Diffusion ; Knudsen number ; Solid oxide fuel cell ; Sintering ; Oxide ; Thermodynamics ; Porous medium ; Composite material ; Chemical engineering ; Mechanics ; Chemistry ; Finite element method ; Physical chemistry ; Metallurgy ; Physics Advancements in Solid Oxide Fuel Cells ; Chemical Looping and Thermochemical Processes ; Catalytic Processes in Materials Science
Authors: Keenan Zhuo | Jing Wang | Jianping Gao | Uzi Landman | M. Y. Chou
Source: Physical review. B./Physical review. B (article, 2020-08-04)
Field: Materials Science — Materials Chemistry

Liquidlike Cu atom diffusion in weakly ionic compounds <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Cu</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi mathvariant="normal">S</mml:mi></mml:mrow></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Cu</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi>Se</mml:mi></mml:mrow></mml:math> Copper sulphide (${\mathrm{Cu}}_{2}\mathrm{S}$) and copper selenide (${\mathrm{Cu}}_{2}\mathrm{Se}$) are known to exist in solid (S/Se)-liquid (Cu) hybrid phases which exhibit favorable thermoelectrics properties. The diffusion characteristics and its mechanism in these systems are therefore of significant interest. In this paper, we analyze these properties through examining the atomic radial distributions, mean-square displacements, and velocity autocorrelations obtained from ab initio molecular dynamics simulations. Exceptionally high Cu diffusion coefficients with values over ${10}^{\ensuremath{-}5}\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{2}$/s are obtained, indicating the unexpected liquidlike behavior of Cu in these weakly ionic compounds. The diffusion mechanism obtained through analysis of the Cu atomic trajectories is found to be at variance with the previously proposed Chudley-Elliott jump diffusion model. In addition, tunability of these diffusion coefficients via small changes in the stoichiometry, namely, Cu deficiencies, is demonstrated. The higher number of low-frequency acoustic phonon modes associated with Se sublattices, compared to those with S sublattices, correlates well with the experimentally observed thermal conductivity difference between ${\mathrm{Cu}}_{2}\mathrm{S}$ and ${\mathrm{Cu}}_{2}\mathrm{Se}$. Diffusion ; Atom (system on chip) ; Materials science ; Copper ; Ionic bonding ; Physics ; Crystallography ; Thermodynamics ; Condensed matter physics ; Ion ; Chemistry ; Quantum mechanics Advanced Thermoelectric Materials and Devices ; Chalcogenide Semiconductor Thin Films ; Ionic liquids properties and applications
Authors: Asmaa Mohamed | Mohamed E. Mahmoud
Source: Journal of Molecular Liquids (article, 2020-04-08)
Field: Chemistry — Inorganic Chemistry

Metoprolol beta-blocker decontamination from water by the adsorptive action of metal-organic frameworks-nano titanium oxide coated tin dioxide nanoparticles Adsorption ; Human decontamination ; Titanium dioxide ; Langmuir adsorption model ; Tin dioxide ; Nanocomposite ; Chemistry ; Zeta potential ; Inorganic chemistry ; Tin ; Nuclear chemistry ; Chemical engineering ; Nanoparticle ; Materials science ; Organic chemistry ; Nanotechnology ; Metallurgy ; Waste management Metal-Organic Frameworks: Synthesis and Applications ; Covalent Organic Framework Applications ; Adsorption and biosorption for pollutant removal
Authors: Saruchi Saruchi | Rashim Verma | Vaneet Kumar | Asma A. Alothman
Source: Journal of Environmental Health Science and Engineering (article, 2020-09-30)
Field: Chemistry — Organic Chemistry

Comparison between removal of Ethidium bromide and eosin by synthesized manganese (II) doped zinc (II) sulphide nanoparticles: kinetic, isotherms and thermodynamic studies Freundlich equation ; Adsorption ; Langmuir ; Eosin ; Nanoparticle ; Nuclear chemistry ; Langmuir adsorption model ; Chemistry ; Zinc ; Fourier transform infrared spectroscopy ; Analytical Chemistry (journal) ; Materials science ; Chemical engineering ; Physical chemistry ; Chromatography ; Organic chemistry ; Nanotechnology Nanomaterials for catalytic reactions ; Adsorption and biosorption for pollutant removal ; Extraction and Separation Processes
Authors: Soumaya Nasri | Melek Hajji | Mouhieddinne Guergueb | Selma Dhifaoui | Valérie Marvaud | Frédérique Loiseau | Florian Molton | Thierry Roisnel | Taha Guerfel | Habib Nasri
Source: Journal of Molecular Structure (article, 2020-11-27)
Field: Materials Science — Materials Chemistry

Spectroscopic, Electrochemical, Magnetic and Structural Characterization of an Hexamethylenetetramine Co(II) Porphyrin Complex – Application in the Catalytic Degradation of Vat Yellow 1 dye Chemistry ; Hexamethylenetetramine ; Porphyrin ; Aqueous solution ; Photochemistry ; Cyclic voltammetry ; Reactivity (psychology) ; Catalysis ; Photodegradation ; Inorganic chemistry ; Electrochemistry ; Physical chemistry ; Organic chemistry ; Photocatalysis Porphyrin and Phthalocyanine Chemistry ; Metal complexes synthesis and properties ; Electrochemical Analysis and Applications
Authors: Abideen Idowu Adeogun | Oluremi Abosede Osideko | Mopelola Abidemi Idowu | Shappur Vahidhabanu | Oluseyi Adeboye Akinloye | B. Ramesh Babu
Source: SN Applied Sciences (article, 2020-04-02)
Field: Chemistry — Organic Chemistry

Chitosan supported CoFe2O4 for the removal of anthraquinone dyes: kinetics, equilibrium and thermodynamics studies Adsorption ; Freundlich equation ; Langmuir ; Chemistry ; Anthraquinone ; Kinetics ; Aqueous solution ; Reaction rate constant ; Langmuir adsorption model ; Methylene blue ; Nuclear chemistry ; Organic chemistry Nanomaterials for catalytic reactions ; Adsorption and biosorption for pollutant removal ; Iron oxide chemistry and applications
Authors: Gregor N. C. Simm | Robert Pinsler | José Miguel Hernández-Lobato
Source: arXiv (Cornell University) (preprint, 2020-02-18)
Field: Materials Science — Materials Chemistry

Reinforcement Learning for Molecular Design Guided by Quantum Mechanics Automating molecular design using deep reinforcement learning (RL) holds the promise of accelerating the discovery of new chemical compounds. Existing approaches work with molecular graphs and thus ignore the location of atoms in space, which restricts them to 1) generating single organic molecules and 2) heuristic reward functions. To address this, we present a novel RL formulation for molecular design in Cartesian coordinates, thereby extending the class of molecules that can be built. Our reward function is directly based on fundamental physical properties such as the energy, which we approximate via fast quantum-chemical methods. To enable progress towards de-novo molecular design, we introduce MolGym, an RL environment comprising several challenging molecular design tasks along with baselines. In our experiments, we show that our agent can efficiently learn to solve these tasks from scratch by working in a translation and rotation invariant state-action space. Reinforcement learning ; Computer science ; Heuristic ; Cartesian coordinate system ; Invariant (physics) ; Space (punctuation) ; Action (physics) ; Chemical space ; Scratch ; Class (philosophy) ; Quantum ; Theoretical computer science ; Artificial intelligence ; Physics ; Chemistry ; Quantum mechanics ; Mathematics Machine Learning in Materials Science ; Computational Drug Discovery Methods ; Innovative Microfluidic and Catalytic Techniques Innovation
Authors: Dawei Zhang | Hui-Lan Fan | Wenzhao Zhang | Cheng-Ji Li | Sanzhong Luo | Hong‐Bo Qin
Source: Chemical Communications (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Collective enantioselective total synthesis of (+)-sinensilactam A, (+)-lingzhilactone B and (−)-lingzhiol: divergent reactivity of styrene The collective total synthesis of (+)-sinensilactam A, (+)-lingzhilactone B, (+)-lingzhilactone C and (-)-lingzhiol has been accomplished from a common epoxide intermediate 9. Chemoselective epoxy opening with either an aryl or alkene moiety of styrene led to different carbon skeletons, which can be advanced to a divergent and concise total synthesis of four meroterpenoids. Enantioselective synthesis ; Epoxide ; Reactivity (psychology) ; Styrene ; Total synthesis ; Chemistry ; Stereochemistry ; Organic chemistry ; Catalysis ; Copolymer Chemical synthesis and alkaloids ; Synthetic Organic Chemistry Methods ; Advanced Synthetic Organic Chemistry
Authors: Linda S. Schadler | W. Chen | L. Catherine Brinson | Ravishankar Sundararaman | P. K. Gupta | Prajakta Prabhune | Akshay Iyer | Y Wang | Abhishek Shandilya
Source: Journal of Physics D Applied Physics (article, 2020-04-20)
Field: Materials Science — Materials Chemistry

A perspective on the data-driven design of polymer nanodielectrics Polymer Nanodielectrics are an emerging class of materials with intriguing combinations of properties. They have application in everything from energy storage to high voltage electrical transmission, and energy generation. This article focuses on insulating nanodielectrics. In all cases, however, the complex set of parameters controlling the properties have made it difficult to both validate models and develop a design methodology. This paper demonstrates a recent approach to developing a data driven design methodology grounded in physics-based models and experimental calibration. Specifically, it combines finite element modeling of dielectric constant and loss functions with a Monte Carlo multi-scale simulation of carrier hopping to predict break down strength predictions. In both cases, the filler dispersion and interface properties are explicitly taken into to account to compute objective functions for ideal nanodielectric insulators. Using a Gaussian process for meta-modeling and multi-objective optimization of these computational predictions for polystyrene-silica composites, this paper identifies the Pareto frontiers with respect to loading and dispersion of nanofillers for maximizing breakdown strength and minimizing the dielectric constant and loss tangents. Perspective (graphical) ; Polymer science ; Polymer ; Materials science ; Polymer chemistry ; Composite material ; Computer science ; Artificial intelligence High voltage insulation and dielectric phenomena ; Dielectric materials and actuators ; Smart Materials for Construction
Authors: Yingshuai Liu | Jianwei Tan
Source: IEEE Access (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Experimental Study on Solid SCR Technology to Reduce NO<sub>x</sub> Emissions from Diesel Engines To solve the problems of low exhaust temperature NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> conversion efficiency of urea Selective Catalytic Reduction (SCR) and easy production of urea crystals during actual vehicle operation, this paper studies the effect of solid SCR on NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> emission on the engine bench. The experimental results show that for a solid SCR carrying the same reducing agent, its volume is only 1/3 the volume of urea SCR. When the exhaust temperature is 160°C, the NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> conversion efficiency of the solid SCR system can reach 40%. Based on the same ammonia-nitrogen ratio setting, the World Harmonized Steady Cycle (WHSC) NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> conversion efficiency is improved by 3.3%, and the World Harmonized Transient Cycle (WHTC) NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> conversion efficiency is increased by 4.5%. When the solid SCR injection temperature is reduced to 160°C, the NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> conversion efficiency is significantly improved, which is 9.7% and 15.5% higher than that of the 200°C solid SCR system and the urea SCR system, respectively, and the number of power base windows is between [0 20]. The NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> emission of diesel vehicles matching the urea SCR system is significantly higher, reaching 2.38 and 1.73 times that of the solid SCR system with a starting temperature of 160°C and 200°C, respectively. Urea ; Diesel fuel ; Ammonia ; Materials science ; Computer science ; Physics ; Chemistry ; Organic chemistry Catalytic Processes in Materials Science ; Industrial Gas Emission Control ; Gas Sensing Nanomaterials and Sensors
Authors: Pao Li | Xinxin Zhang | Yu Zheng | Fei Yang | Liwen Jiang | Xia Liu | Shenghua Ding | Yang Shan
Source: Food Science & Nutrition (article, 2020-12-08)
Field: Chemistry — Analytical Chemistry

A novel method for the nondestructive classification of different‐age Citri Reticulatae Pericarpium based on data combination technique The quality of Citri Reticulatae Pericarpium (CRP) is closely correlated with the aging time. However, CRPs in different storage ages are similar in appearance, and the young CRP may be labeled as the aged one to obtain the excess profit by some unscrupulous traders. Most traditional analysis methods are laborious and time-consuming, and they can hardly realize the nondestructive classification. In this paper, a novel method based on near-infrared diffuse reflectance spectroscopy (NIRDRS) and data combination technique for the nondestructive classification of different-age CRPs was proposed. The CRPs in different storage ages (5, 10, 15, 20, and 25 years) were measured. The near-infrared spectra of outer skin and inner capsule were obtained. Principal component analysis (PCA), soft independent modeling of class analogy (SIMCA), and Fisher's linear discriminant analysis (FLD), with different data pretreatment methods, were used for the classification analysis. Data combination of the outer skin and inner capsule spectra was discussed for further improving the classification results. The results show that multiple sensors provide more useful and complementary information than a single sensor does for improving the prediction accuracy. With the help of data combination strategy, 100% prediction accuracy can be obtained with both second-order derivative-FLD and continuous wavelet transform-multiplicative scatter correction-FLD methods. Artificial intelligence ; Pattern recognition (psychology) ; Mathematics ; Statistics ; Computer science Spectroscopy and Chemometric Analyses ; Spectroscopy Techniques in Biomedical and Chemical Research ; Traditional Chinese Medicine Studies