jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Paul Clabaut | Paul Fleurat‐Lessard | Carine Michel | Stephan N. Steinmann
Source: ChemRxiv (preprint, 2020-01-27)
Field: Chemistry — Physical and Theoretical Chemistry

Ten Facets, One Force Field: The GAL19 Force Field for Water - Noble Metal Interfaces &lt;div&gt;Understanding the structure of the water/metal interfaces plays an important role in many are as ranging from surface chemistry to environmental processes. Due to their intrinsic complexity, the water/metal interfaces cannot yet be adequately described by quantum mechanical approaches and accurate force-ﬁelds are therefore needed. We develop and parametrize GAL19, a novel force-ﬁeld to describe the interaction of water with two facets (111 and 100) of ﬁve metals (Pt, Pd, Au, Ag, Cu). To increase transferability compared to its predecessor GAL17, the water-metal interaction is described as a sum of pair-wise terms. The interaction energy has three contributions: (i) physisorption is described via a Tang and Toennies potential, (ii) chemisorption and surface corrugation relies on an attractive Gaussian term and (iii) the angular dependence is explicitly included as a truncated Fourier series. 13 parameters are used for each metal surface and were ﬁtted on 250 water adsorption energies computed at the PBE+dDsC level. &lt;/div&gt;&lt;div&gt;The performance of GAL19 was evaluated on a set of more than 600 DFT adsorption energies for each surface, leading to an average root mean square deviation (RMSD) of only 1 kcal/mol, correctly reproducing the adsorption trends: strong on Pt and Pd but weaker on Ag, Au and Cu. This force-ﬁeld was then used to simulate the water/metal interface for all ten surfaces for 1 ns. Structural analyses reveal similar tendencies for all surfaces: a ﬁrst, dense water layer that is mostly adsorbed on the metal top sites, and a second layer up to around 6 Å, which is less structured. On Pt and Pd, the ﬁrst layer is strongly organized with water lying ﬂat on the surface. The pairwise additive functional form allows to simulate the water adsorption on alloys, which is demonstrated at the example of Ag/Cu and Au/Pt alloys. The water/Ag-Cu interface is predicted to be disordered with water mostly adsorbed on Cu which should exacerbate the Ag reactivity. On the contrary, incorporating Pt into Au materials leads to a structuring of the water interface. Our promising results make GAL19 an ideal candidate to get representative sampling of complex metal/water interfaces as a ﬁrst step towards accurate estimation of free energies of reactions in solution at the metal interface.&lt;/div&gt; Physisorption ; Chemisorption ; Adsorption ; Force field (fiction) ; Metal ; Potential of mean force ; Noble metal ; Gaussian surface ; Chemistry ; Chemical physics ; Materials science ; Physical chemistry ; Computational chemistry ; Physics ; Molecular dynamics ; Quantum mechanics ; Metallurgy Electrostatics and Colloid Interactions ; Surface and Thin Film Phenomena ; Chemical and Physical Properties of Materials
Authors: Yao Wang | Jianqing Feng | Lihua Jin | Chengshan Li
Source: REVIEWS ON ADVANCED MATERIALS SCIENCE (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Photocatalytic reduction of graphene oxide with cuprous oxide film under UV-vis irradiation Abstract We have grown Cu 2 O films by different routes including self-oxidation and metal-organic deposition (MOD). The reduction efficiency of Cu 2 O films on graphene oxide (GO) synthesized by modified Hummer’s method has been studied. Surface morphology and chemical state of as-prepared Cu 2 O film and GO sheets reduced at different conditions have also been investigated using atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). Results show that self-oxidation Cu 2 O film is more effective on phtocatalytic reduction of GO than MOD-Cu 2 O film. Moreover, reduction effect of self-oxidation Cu 2 O film to GO is comparable to that of environmental-friendly reducing agent of vitamin C. The present results offer a potentially eco-friendly and low-cost approach for the manufacture of reduced graphene oxide (RGO) by photocatalytic reduction. Graphene ; X-ray photoelectron spectroscopy ; Oxide ; Materials science ; Photocatalysis ; Chemical engineering ; Reducing agent ; Metal ; Deposition (geology) ; Nanotechnology ; Catalysis ; Metallurgy ; Chemistry ; Organic chemistry Copper-based nanomaterials and applications ; Nanomaterials for catalytic reactions ; Gold and Silver Nanoparticles Synthesis and Applications
Authors: Renxuan Xie | Enrique D. Gomez | Youngmin Lee | Melissa A. Aplan | Abigail M. Fenton | Ashley E. Masucci | Fabian Kempe | Michael Sommer | Christian W. Pester | Ralph H. Colby
Source: Nature Communications (article, 2020-02-14)
Field: Materials Science — General Materials Science

Glass transition temperature from the chemical structure of conjugated polymers The glass transition temperature (T<sub>g</sub>) is a key property that dictates the applicability of conjugated polymers. The T<sub>g</sub> demarks the transition into a brittle glassy state, making its accurate prediction for conjugated polymers crucial for the design of soft, stretchable, or flexible electronics. Here we show that a single adjustable parameter can be used to build a relationship between the T<sub>g</sub> and the molecular structure of 32 semiflexible (mostly conjugated) polymers that differ drastically in aromatic backbone and alkyl side chain chemistry. An effective mobility value, ζ, is calculated using an assigned atomic mobility value within each repeat unit. The only adjustable parameter in the calculation of ζ is the ratio of mobility between conjugated and non-conjugated atoms. We show that ζ correlates strongly to the T<sub>g</sub>, and that this simple method predicts the T<sub>g</sub> with a root-mean-square error of 13 °C for conjugated polymers with alkyl side chains. Conjugated system ; Glass transition ; Polymer ; Materials science ; Transition (genetics) ; Chemical physics ; Polymer science ; Chemical engineering ; Nanotechnology ; Chemistry ; Composite material ; Engineering Material Properties and Applications ; Synthesis and properties of polymers ; Polymer Science and Applications
Authors: P.J. Garcı́a Nieto | Esperanza García–Gonzalo | Fernando Sánchez Lasheras | Antonio Bernardo-Sánchez
Source: International Journal of Interactive Multimedia and Artificial Intelligence (article, 2020-11-28)
Field: Materials Science — Materials Chemistry

Chrome Layer Thickness Modelling in a Hard Chromium Plating Process Using a Hybrid PSO/ RBF–SVM–Based Model. The purpose of chromium plating is the creation of a hard and wear-resistant layer of chromium over a metallic surface. The principal feature of chromium plating is its endurance in the face of the wear and corrosion. This industrial process has a vast range of applications in many different areas. In the performance of this process, some difficulties can be found. Some of the most common are melt deposition, milky white chromium deposition, rough or sandy chromium deposition and lack of toughness of the layer or wear and lack of thickness of the layer deposited. This study builds a novel nonparametric method relied on the statistical machine learning that employs a hybrid support vector machines (SVMs) model for the hard chromium layer thickness forecast. The SVM hyperparameters optimization was made with the help of the Particle Swarm Optimizer (PSO). The outcomes indicate that PSO/SVM–based model together with radial basis function (RBF) kernel has permitted to foretell the thickness of the chromium layer created in this industrial process satisfactorily. Thus, two kinds of outcomes have been obtained: firstly, this model permits to determine the ranking of relevance of the seven independent input variables investigated in this industrial process. Finally, the high achievement and lack of complexity of the model indicate that the PSO/SVM method is very interesting compared to other conventional foretelling techniques, since a coefficient of determination of 0.9952 is acquired. Computer science ; Chrome plating ; Layer (electronics) ; Plating (geology) ; Support vector machine ; Process (computing) ; Particle swarm optimization ; Artificial intelligence ; Machine learning ; Materials science ; Composite material ; Operating system ; Geology Metallurgy and Material Science ; Metallurgical Processes and Thermodynamics
Authors: Mikhaïl Mamatkulov | Vladimir P. Zhdanov
Source: Physical review. E (article, 2020-04-23)
Field: Materials Science — Materials Chemistry

Suppression of hysteresis in absorption of hydrogen by a Pd-Au alloy Hydrogen absorption by Pd exhibits hysteresis loops (provided the temperature is not too high) and represents one of the classical examples of first-order phase transitions in metals. Experiments indicate that addition of even a small amount of Au is able to suppress hysteresis. From this perspective, we analyze the energetics of hydrogen in a Pd-Au alloy by using extensive density-functional-theory (DFT) calculations. The dependence of the hydrogen binding energy on the number (n) of Au atoms forming an adsorption site is found to be appreciably nonlinear. With the DFT input for statistical calculations, we reproduce special features of the hydrogen absorption isotherms and explain the rapid decrease of the corresponding critical temperature with increasing Au fraction. The key factor here is that the phase transition is related primarily to absorption in sites formed only by Pd. With increasing Au amount, the fraction of such sites rapidly decreases, the distance between H atoms located there becomes on average larger, the interaction between them becomes weaker, and accordingly the driving force for the phase transition decreases. It is of interest that all these effects can be illustrated by taking only the configurations with n≤2 into account. This means that in the context under consideration the fine details of the dependence of the hydrogen binding energy on n are in fact not too important. Materials science ; Hysteresis ; Alloy ; Hydrogen ; Absorption (acoustics) ; Condensed matter physics ; Atomic physics ; Metallurgy ; Physics ; Composite material ; Quantum mechanics Hydrogen Storage and Materials ; nanoparticles nucleation surface interactions ; Advanced Chemical Physics Studies
Authors: Alice Baux | Guillaume Couégnat | Gérard L. Vignoles | Didier Lasseux | Alexander Kuhn | Cristina Carucci | Nicolas Mano | Tien Dung Le
Source: Materials & Design (article, 2020-05-18)
Field: Chemistry — Electrochemistry

Digitization and image-based structure-properties relationship evaluation of a porous gold micro-electrode The advantage of using porous materials for biofuel cells and biosensors is their very large internal surface area (where electron exchange takes place) compared to the overall material volume, yielding much larger current densities than on a bare solid electrode of the same size. However, limitations occur because of mass transfer resistance through the pores. We describe here a bottom-up approach to optimize the design of such materials, through the analysis and modeling of their porous structure. Electrodes prepared by replicating stacked Langmuir-Blodgett films, with 1-μm diameter interconnected spherical pores, were studied. Since pore window dimensions are around 100 nm, Focused Ion Beam-Scanning Electron Microscopy (FIB-SEM) has been performed to obtain a 3D reconstruction of the porous medium. Then, a determination of the geometrical characteristics has been achieved through image analysis. The structure of the sphere packing, the shape and size of the connections between spheres, the distances between spheres, the sphere diameters and the specific surface area have been analyzed. The porous medium is close to a face-centered cubic arrangement of spherical pores, but several deviations from ideality are present: missing pores (point defects), stacking errors (dislocations), and incomplete connection between spheres (only 50% of the ideal sphere connections are present). The consequence of such defects on transport is studied through image-based simulations of mass diffusion in the actual porous medium and in similar ideal media. Materials science ; SPHERES ; Porosity ; Electrode ; Porous medium ; Scanning electron microscope ; Stacking ; Focused ion beam ; Nanotechnology ; Composite material ; Ion Electrochemical Analysis and Applications ; Nanoporous metals and alloys ; Electrodeposition and Electroless Coatings
Authors: Mika Sarvilahti | Audun Skaugen | Lasse Laurson
Source: APL Materials (article, 2020-10-01)
Field: Materials Science — Materials Chemistry

Machine learning depinning of dislocation pileups We study a one-dimensional model of a dislocation pileup driven by an external stress and interacting with random quenched disorder, focusing on the predictability of the plastic deformation process. Upon quasistatically ramping up the externally applied stress from zero, the system responds by exhibiting an irregular stress–strain curve consisting of a sequence of strain bursts, i.e., critical-like dislocation avalanches. The strain bursts are power-law distributed up to a cutoff scale that increases with the stress level up to a critical flow stress value. There, the system undergoes a depinning phase transition and the dislocations start moving indefinitely, i.e., the strain burst size diverges. Using sample-specific information about the pinning landscape as well as the initial dislocation configuration as input, we employ predictive models such as linear regression, simple neural networks, and convolutional neural networks to study the predictability of the simulated stress–strain curves of individual samples. Our results show that the response of the system—including the flow stress value—can be predicted quite well, with the correlation coefficient between the predicted and actual stress exhibiting a non-monotonic dependence on strain. We also discuss our attempts to predict the individual strain bursts. Dislocation ; Predictability ; Stress (linguistics) ; Cutoff ; Flow stress ; Deformation (meteorology) ; Convolutional neural network Microstructure and mechanical properties ; Theoretical and Computational Physics ; Machine Learning in Materials Science
Authors: Massimo Cuscunà | Mariachiara Manoccio | Marco Esposito | M. Scuderi | Giuseppe Nicotra | Iolena Tarantini | Angelo Melcarne | Vittorianna Tasco | María Losurdo | A. Passaseo
Source: Materials Horizons (article, 2020-10-22)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Gallium chiral nanoshaping for circular polarization handling In this work we report the local growth of ordered arrays of 3D core-shell chiral nanohelices based on plasmonic gallium metal. The structures can be engineered in a single step using focused ion beam induced deposition, where a Ga<sup>+</sup> ion source is used to shape the metallic nanohelix core, while the dielectric precursor is dissociated to create dielectric shells. The solubility of gallium in the different investigated dielectric matrices controls the core-shell thickness ratio of the nanohelices. The chiral plasmonic behaviour of these gallium-based nanostructures is experimentally measured by circularly polarized light transmission through nanostructure arrays and compared with numerical simulations. Large chiroptical effects in the visible range are demonstrated due to the plasmonic effects arising from gallium nanoclusters in the core. Gallium ; Nanoclusters ; Plasmon ; Materials science ; Dielectric ; Nanostructure ; Polarization (electrochemistry) ; Focused ion beam ; Optoelectronics ; Metal ; Nanotechnology ; Ion ; Chemistry ; Organic chemistry ; Physical chemistry Metamaterials and Metasurfaces Applications ; Plasmonic and Surface Plasmon Research ; Gold and Silver Nanoparticles Synthesis and Applications
Authors: Aura Rusu
Source: FARMACIA (article, 2020-10-27)
Field: Materials Science — Polymers and Plastics

COMPATIBILITY STUDY OF FOUR BINARY COMBINATIONS OF ACTIVE INGREDIENTS FOR DERMAL FILM FORMING SYSTEMS Adapalene (ADA), levofloxacin (LEV), meloxicam (MEL) and miconazole nitrate (MIC) were selected as potential active ingredients for film systems with dermal or transdermal delivery. This study aimed to evaluate the compatibility of four binary mixtures -ADA and LEV (M1), ADA and MIC (M2), LEV and MEL (M3), and LEV and MIC (M4)combinations for new bioadhesive polymeric matrix dermal systems produced by the casting solvent evaporation technique. The Fouriertransform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and molecular modelling (MM) were used to characterise and evaluate the compatibility between the selected active substances. In the FTIR data, M1, M2, and M4 mixtures presented a good compatibility. DSC revealed different chemical interactions as the temperature rose above 160C, especially for M3 and M4. Through MM technique, interactions were found on the M2 and M3 mixtures. Following the correlation of all obtained results, the best compatibility was found to be on M1 and M4 combinations. Compatibility (geochemistry) ; Binary number ; Materials science ; Composite material ; Mathematics ; Arithmetic Textile materials and evaluations ; Advancements in Transdermal Drug Delivery ; Dyeing and Modifying Textile Fibers
Authors: Shaimaa M. Essa | Wisam Hindawi Hoidy
Source: Nano Biomedicine and Engineering (article, 2020-06-03)
Field: Chemistry — Organic Chemistry

Spectrophotometric Determination of Cobalt(II) and Lead(II) Using (1,5-Dimethyl-2-Phenyl-4-((2,3,4-Trihydroxy Phenyl) Diazenyl)-1H-Pyrazol-3(2H)-One) as Organic Reagent: Using It as Antimicrobial and Antioxidants The azo organic reagent (1,5-dimethyl-2-phenyl-4-((2,3,4-trihydroxy phenyl) diazenyl)-1H-pyrazol-3(2H)-one) (DPTPD) was prepared and used for the spectrophotometric determination of cobalt(II) and Lead(II), by the selective and surfactant-sensitized method based on the ternary complexes formation of Co(II) and Pb(II). The reagent had absorption maximum at 381 nm, and reacted with Co 2+ to form a purple reddish complex with max = 430 nm at pH = 7.5, while it formed a red complex with Pb 2+ of max = 417 nm at pH= 6. Beer's law for the determination over the range of 1-25 ppm and 1-33 ppm for Co(II) and Pb(II), respectively. The molar absorptivity () and Sandell's sensitivity values of Co(II) and Pb(II) complexes were found to be 1.0210 4 , 3.310 4 mol -1 cm -1 , and 0.0725, 0.0269 g cm -2 at 430, 417 nm, respectively. The stability constant was found to be 1.110 8 L mol -1 and 2.310 8 L mol -1 for Co(II) and Pb(II), respectively. Detection limit relative standard deviation, relative error and recovery were predestined for 15 ppm standard solution of Co(II) and Pb(II) complexes, respectively. The important interferences with most ions like Cr +3 , Mn 2+ , Fe 3+ , Zn 2+ , Hg 2+ , Mo +2 , Pt 2+ and Cd +2 were studied using the appropriate masking agents. The method was applied for the determination of Co(II) in filling sample; the result obtained was incompatible with that by the flame atomic absorption spectrometry method. The organic reagent (DPTPD) was diagnosed as an antibacterial and an antioxidant. Reagent ; Cobalt ; Chemistry ; Nuclear chemistry ; Medicinal chemistry ; Organic chemistry Inorganic and Organometallic Chemistry ; Synthesis and biological activity
Authors: Madison Wenzlick | Jennifer Bauer | Kelly Rose | Jeffrey A. Hawk | Ram Devanathan
Source: Integrating materials and manufacturing innovation (article, 2020-01-16)
Field: Materials Science — Materials Chemistry

Data Assessment Method to Support the Development of Creep-Resistant Alloys Data quality ; Computer science ; Metadata ; Standardization ; Quality (philosophy) ; Reliability engineering ; Data mining ; Usability ; Sample (material) ; Database ; Data science ; Metric (unit) ; Engineering Nuclear Materials and Properties ; High Temperature Alloys and Creep ; Technology Assessment and Management
Authors: Christoph Metzke | Werner Frammelsberger | Jonas Weber | Fabian Kühnel | Kaichen Zhu | Mario Lanza | Günther Benstetter
Source: Materials (article, 2020-01-22)
Field: Materials Science — Materials Chemistry

On the Limits of Scanning Thermal Microscopy of Ultrathin Films Heat transfer processes in micro- and nanoscale devices have become more and more important during the last decades. Scanning thermal microscopy (SThM) is an atomic force microscopy (AFM) based method for analyzing local thermal conductivities of layers with thicknesses in the range of several nm to µm. In this work, we investigate ultrathin films of hexagonal boron nitride (h-BN), copper iodide in zincblende structure (γ-CuI) and some test sample structures fabricated of silicon (Si) and silicon dioxide (SiO<sub>2</sub>) using SThM. Specifically, we analyze and discuss the influence of the sample topography, the touching angle between probe tip and sample, and the probe tip temperature on the acquired results. In essence, our findings indicate that SThM measurements include artefacts that are not associated with the thermal properties of the film under investigation. We discuss possible ways of influence, as well as the magnitudes involved. Furthermore, we suggest necessary measuring conditions that make qualitative SThM measurements of ultrathin films of h-BN with thicknesses at or below 23 nm possible. Scanning thermal microscopy ; Materials science ; Nanoscopic scale ; Microscopy ; Silicon ; Scanning probe microscopy ; Silicon dioxide ; Characterization (materials science) ; Thermal ; Hexagonal boron nitride ; Nanotechnology ; Silicon nitride ; Optoelectronics ; Analytical Chemistry (journal) ; Optics ; Chemistry ; Composite material Thermal properties of materials ; Advanced Thermoelectric Materials and Devices ; Thermography and Photoacoustic Techniques
Authors: Nicolas Cottura | Alice Howarth | Rajith K. R. Rajoli | Marco Siccardi
Source: The Journal of Clinical Pharmacology (review, 2020-11-01)
Field: Materials Science — Biomaterials

The Current Landscape of Novel Formulations and the Role of Mathematical Modeling in Their Development Drug delivery is an integral part of the drug development process, influencing safety and efficacy of active pharmaceutical ingredients. The application of nanotechnology has enabled the discovery of novel formulations for numerous therapeutic purposes across multiple disease areas. However, evaluation of novel formulations in clinical scenarios is slow and hampered due to various ethical and logistical barriers. Computational models have the ability to integrate existing domain knowledge and mathematical correlations, to rationalize the feasibility of using novel formulations for safely enhancing drug delivery, identifying suitable candidates, and reducing the burden on preclinical and clinical studies. In this review, types of novel formulations and their application through several routes of administration and the use of modeling approaches that can find application in different stages of the novel formulation development process are discussed. Current (fluid) ; Development (topology) ; Computer science ; Mathematics ; Geology ; Oceanography Nanoparticle-Based Drug Delivery ; Protein purification and stability ; Drug Solubulity and Delivery Systems