jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Akhilesh Kr. Singh | Uddipta Kar | Matthew D. Redell | Tsung‐Chi Wu | Wei-Hsiang Peng | Bipul Das | Satish Kumar | Wei‐Cheng Lee | Wei‐Li Lee
Source: npj Quantum Materials (article, 2020-07-06)
Field: Materials Science — Materials Chemistry

Field-induced resistance peak in a superconducting niobium thin film proximity coupled to a surface reconstructed SrTiO3 Abstract Oxygen vacancy is known to play an important role for the physical properties in SrTiO 3 (STO)-based systems. On the surface, rich structural reconstructions had been reported owing to the oxygen vacancies, giving rise to metallic surface states and unusual surface phonon modes. More recently, an intriguing phenomenon of a huge superconducting transition temperature enhancement was discovered in a monolayer FeSe on STO substrate, where the surface reconstructed STO (SR-STO) may play a role. In this work, SR-STO substrates were prepared via thermal annealing in ultra-high vacuum followed by low energy electron diffraction analyses on surface structures. Thin Nb films with different thicknesses ( d ) were then deposited on the SR-STO. The detailed studies of the magnetotransport and superconducting property in the Al(1 nm)/Nb( d )/SR-STO samples revealed a large positive magnetoresistance and a pronounced resistance peak near the onset of the resistive superconducting transition in the presence of an in-plane field. Remarkably, the amplitude of the resistance peak increases with increasing fields, reaching a value of nearly 57% of the normal state resistance at 9 T. Such resistance peaks were absent in the control samples of Al(1 nm)/Nb( d )/STO and Al(1 nm)/Nb( d )/SiO 2 . Combining with DFT calculations for SR-STO, we attribute the resistance peak to the interface resistance from the proximity coupling of the superconducting niobium to the field-enhanced long-range magnetic order in SR-STO that arises from the spin-polarized in-gap states due to oxygen vacancies. Condensed matter physics ; Superconductivity ; Materials science ; Niobium ; Magnetoresistance ; Annealing (glass) ; Thin film ; Magnetic field ; Nanotechnology ; Physics ; Metallurgy Electronic and Structural Properties of Oxides ; Magnetic and transport properties of perovskites and related materials ; Iron-based superconductors research
Authors: Dominik Kürten | Iyas Khader | Andreas Kailer
Source: Materials and Corrosion (article, 2020-02-25)
Field: Materials Science — Metals and Alloys

Determining the effective hydrogen diffusion coefficient in 100Cr6 Abstract In the present study, the diffusion constant for hydrogen in hardened 100Cr6 was measured in permeation tests. The tests were conducted on samples of different thicknesses. The diffusivity of hydrogen was also measured in prestrained samples to study the influence of plastic strain on the diffusion rate. A finite element‐based diffusion model was applied to confirm the experimental results by computing the concentrations of diffusible hydrogen and trapped hydrogen due to deformation‐induced defects. The results showed that the concentration of trapped hydrogen remained very low throughout the plastic strain regime under consideration. The average effective diffusion coefficient of hydrogen in 100Cr6 at 30°C was found to be D eff = 4.9 × 10 −12 m 2 /s. Hydrogen ; Diffusion ; Thermal diffusivity ; Materials science ; Thermodynamics ; Effective diffusion coefficient ; Analytical Chemistry (journal) ; Chemistry ; Chromatography ; Physics ; Medicine ; Organic chemistry Hydrogen embrittlement and corrosion behaviors in metals ; Corrosion Behavior and Inhibition ; Microstructure and Mechanical Properties of Steels
Authors: Melisa del Barrio | Gabriel Luna-López | Marcos Pita
Source: Sensors (review, 2020-06-09)
Field: Chemistry — Electrochemistry

Enhancement of Biosensors by Implementing Photoelectrochemical Processes Research on biosensors is growing in relevance, taking benefit from groundbreaking knowledge that allows for new biosensing strategies. Electrochemical biosensors can benefit from research on semiconducting materials for energy applications. This research seeks the optimization of the semiconductor-electrode interfaces including light-harvesting materials, among other improvements. Once that knowledge is acquired, it can be implemented with biological recognition elements, which are able to transfer a chemical signal to the photoelectrochemical system, yielding photo-biosensors. This has been a matter of research as it allows both a superior suppression of background electrochemical signals and the switching ON and OFF upon illumination. Effective electrode-semiconductor interfaces and their coupling with biorecognition units are reviewed in this work. Biosensor ; Nanotechnology ; Photoelectrochemistry ; Semiconductor ; Materials science ; Electrode ; Computer science ; Electrochemistry ; Optoelectronics ; Chemistry Electrochemical Analysis and Applications ; Electrochemical sensors and biosensors ; Advanced biosensing and bioanalysis techniques
Authors: Samuel M. Blau | Hetal Patel | Evan Walter Clark Spotte‐Smith | Xiaowei Xie | Shyam Dwaraknath | Kristin A. Persson
Source: ChemRxiv (preprint, 2020-10-01)
Field: Materials Science — Materials Chemistry

A Chemically Consistent Graph Architecture for Massive Reaction Networks Applied to Solid-Electrolyte Interphase Formation Modeling reactivity with chemical reaction networks could yield fundamental mechanistic understanding that would expedite the development of processes and technologies for energy storage, medicine, catalysis, and more. Thus far, reaction networks have been limited in size by chemically inconsistent graph representations of multi-reactant reactions (e.g. A + B reacts to C) that cannot enforce stoichiometric constraints, precluding the use of optimized shortest-path algorithms. Here, we report a chemically consistent graph architecture that overcomes these limitations using a novel multi-reactant representation and iterative cost-solving procedure. Our approach enables the identification of all low-cost pathways to desired products in massive reaction networks containing reactions of any stoichiometry, allowing for the investigation of vastly more complex systems than previously possible. Leveraging our architecture, we construct the first ever electrochemical reaction network from first-principles thermodynamic calculations to describe the formation of the Li-ion solid electrolyte interphase (SEI), which is critical for passivation of the negative electrode. Using this network comprised of nearly 6,000 species and 4.5 million reactions, we interrogate the formation of a key SEI component, lithium ethylene dicarbonate. We automatically identify previously proposed mechanisms as well as multiple novel pathways containing counter-intuitive reactions that have not, to our knowledge, been reported in the literature. We envision that our framework and data-driven methodology will facilitate efforts to engineer the composition-related properties of the SEI - or of any complex chemical process - through selective control of reactivity. Computer science ; Electrochemistry ; Stoichiometry ; Reactivity (psychology) ; Electrolyte ; Chemistry ; Combinatorial chemistry ; Distributed computing ; Electrode ; Organic chemistry Machine Learning in Materials Science ; Electrocatalysts for Energy Conversion ; Fuel Cells and Related Materials
Authors: Huijie Tian | Srinivas Rangarajan
Source: The Journal of Physical Chemistry C (article, 2020-02-17)
Field: Materials Science — Materials Chemistry

Leveraging Thermochemistry Data to Build Accurate Microkinetic Models Ab initio microkinetic modeling, parameterized using density functional theory (DFT) energies, is a common tool to quantify reaction rates and analyze reaction mechanisms a priori in heterogeneous catalysis. Such models, however, often have large prediction errors even if they include plausible reaction steps and correctly model the active sites; this is partially due to the intrinsic inaccuracies of the chosen DFT functional. Borrowing concepts from Bayesian calibration theory, we show that transferable data-driven corrections to DFT energies in the form of Gaussian process models trained on single-crystal adsorption calorimetry data can improve the accuracy of microkinetic models substantially. Specifically, we demonstrate that such corrections improve the predictive accuracy of the microkinetic model of the water-gas shift reaction on single-crystal Cu(111) surface by 3 orders of magnitude. We finally show that Gaussian process corrections serve as informed priors in a Bayesian experimental design framework to learn an accurate a posteriori microkinetic model from few kinetic experiments. We posit that these results suggest that even infusing small, related, high-fidelity thermochemistry data, when available, can systematically and substantially improve the predictive accuracy of microkinetic models. Thermochemistry ; A priori and a posteriori ; Gaussian process ; Density functional theory ; Bayesian probability ; Chemistry ; Statistical physics ; Bayesian optimization ; Computer science ; Gaussian ; Computational chemistry ; Machine learning ; Physics ; Physical chemistry ; Artificial intelligence Machine Learning in Materials Science ; Electrocatalysts for Energy Conversion ; nanoparticles nucleation surface interactions
Authors: Cheng Li | Yi‐Ting Wang | Yi-Ting Wang | Yu Chen | Yong Wang
Source: Analytical Chemistry (article, 2020-06-24)
Field: Materials Science — Materials Chemistry

Hyperbranched Poly(amido amine) Entrapped Tetraphenylethene as a Fluorescence Probe for Sequential Quadruple-Target Detection and Its Potential as a Chemical Logic Gate Fluorescence sensors exhibit great potential as molecular logic gates to perform computation on a nanometer scale. For achieving the more complex artificial intelligence activities, developing complex logic gates using multitarget sensing systems with multi-input characteristics is highly desirable. Herein, a water-soluble quadruple-target fluorescence sensor that embeds a small amount (4.1 wt %) of tetraphenylethene (TPE) units into hyperbranched poly(amido amine) (TPE-HPA) has been designed. The nonfluorescent TPE-HPA could experience the fluorescence "off-on-off-on-off" by sequential addition of sodium hexametaphosphate (SHMP), Fe<sup>3+</sup>, ascorbic acid (AA), and H<sub>2</sub>O<sub>2</sub>. The as-prepared quadruple-target sensor showed good sensitivity and selectivity to SHMP, Fe<sup>3+</sup>, AA, and H<sub>2</sub>O<sub>2</sub>, and the limit of detection values were 29 nM, 20 nM, 0.66 μM, and 0.78 μM, respectively. On the basis of the multitarget sensing nature of TPE-HPA, chemical or electrochemical-induced logic gates were constructed, including YES, NOT, OR, NOR, NAND, INHIBIT, IMP, and higher logic systems. Chemistry ; Amine gas treating ; Fluorescence ; Chemical sensor ; Combinatorial chemistry ; Photochemistry ; Nanotechnology ; Organic chemistry ; Physical chemistry Luminescence and Fluorescent Materials ; Molecular Sensors and Ion Detection ; Advanced biosensing and bioanalysis techniques
Authors: James Xiao | Yun Liu | Violette Steinmetz | Mustafa Çaǧlar | Jeffrey Mc Hugh | Tomi K. Baikie | Nicolas Gauriot | Małgorzata Nguyen | Edoardo Ruggeri | Zahra Andaji‐Garmaroudi | Samuel D. Stranks | Laurent Legrand | Thierry Barisien | Richard H. Friend | Neil C. Greenham | Akshay Rao | Raj Pandya
Source: ACS Nano (article, 2020-10-12)
Field: Materials Science — Materials Chemistry

Optical and Electronic Properties of Colloidal CdSe Quantum Rings Luminescent colloidal CdSe nanorings are a recently developed type of semiconductor structure that have attracted interest due to the potential for rich physics arising from their nontrivial toroidal shape. However, the exciton properties and dynamics of these materials with complex topology are not yet well understood. Here, we use a combination of femtosecond vibrational spectroscopy, temperature-resolved photoluminescence (PL), and single-particle measurements to study these materials. We find that on transformation of CdSe nanoplatelets to nanorings, by perforating the center of platelets, the emission lifetime decreases and the emission spectrum broadens due to ensemble variations in the ring size and thickness. The reduced PL quantum yield of nanorings (∼10%) compared to platelets (∼30%) is attributed to an enhanced coupling between (i) excitons and CdSe LO-phonons at 200 cm<sup>-1</sup> and (ii) negatively charged selenium-rich traps, which give nanorings a high surface charge (∼-50 mV). Population of these weakly emissive trap sites dominates the emission properties with an increased trap emission at low temperatures relative to excitonic emission. Our results provide a detailed picture of the nature of excitons in nanorings and the influence of phonons and surface charge in explaining the broad shape of the PL spectrum and the origin of PL quantum yield losses. Furthermore, they suggest that the excitonic properties of nanorings are not solely a consequence of the toroidal shape but also a result of traps introduced by puncturing the platelet center. Materials science ; Colloid ; Quantum dot ; Nanotechnology ; Quantum ; Optoelectronics ; Chemical physics ; Chemistry ; Physics ; Physical chemistry ; Quantum mechanics Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films ; Nonlinear Optical Materials Studies
Authors: Qingyu Yang | Pengfei Qiu | Xun Shi | Lidong Chen
Source: Journal of Inorganic Materials (article, 2020-10-19)
Field: Materials Science — Materials Chemistry

Application of Entropy Engineering in Thermoelectrics As the extension of high-entropy alloy, entropy engineering has been already extensively used in thermoelectrics because it can guide the optimization of thermoelectric (TE) performance from the aspects of both electrical and thermal transports. Due to the inherent material gene-like feature, entropy can be used as a performance indicator to rapidly screen new multicomponent TE materials. In this review, we first reveal the reason why entropy can be used as the performance indicator of TE materials. The physical mechanisms of enhanced structure symmetry, improved Seebeck coefficient, and suppressed lattice thermal conductivity as a result of the increased configurational entropy are discussed. Then, the applications of entropy engineering in typical TE materials, such as liquid-like materials and IV-VI semiconductors, are outlined, and the approach to screen and identify candidate multicomponent TE materials with high configurational entropy is introduced. Finally, the future directions for entropy engineering are highlighted. Materials science ; Thermoelectric materials ; Engineering physics ; Composite material ; Engineering ; Thermal conductivity Advanced Thermoelectric Materials and Devices ; Thermal properties of materials ; Advanced Thermodynamics and Statistical Mechanics
Authors: Edwin C. Constable | Catherine E. Housecroft
Source: Molecules (review, 2020-06-05)
Field: Chemistry — Physical and Theoretical Chemistry

Chemical Bonding: The Journey from Miniature Hooks to Density Functional Theory Our modern understanding of chemistry is predicated upon bonding interactions between atoms and ions resulting in the assembly of all of the forms of matter that we encounter in our daily life. It was not always so. This review article traces the development of our understanding of bonding from prehistory, through the debates in the 19th century C.E. bearing on valence, to modern quantum chemical models and beyond. Density functional theory ; Chemical bond ; Quantum chemical ; Valence bond theory ; Valence (chemistry) ; Chemical physics ; Prehistory ; Chemistry ; Nanotechnology ; Computational chemistry ; Materials science ; Molecule ; History ; Archaeology ; Organic chemistry ; Molecular orbital History and advancements in chemistry ; Various Chemistry Research Topics ; Chemistry and Chemical Engineering
Authors: Lingru Zheng | Maja Rücker | Tom Bultreys | Apostolos Georgiadis | Miranda M. Mooijer-van den Heuvel | Fernando Bresme | J. P. Martin Trusler | Erich A. Müller
Source: Energies (article, 2020-06-01)
Field: Materials Science — Surfaces, Coatings and Films

Surrogate Models for Studying the Wettability of Nanoscale Natural Rough Surfaces Using Molecular Dynamics A molecular modeling methodology is presented to analyze the wetting behavior of natural surfaces exhibiting roughness at the nanoscale. Using atomic force microscopy, the surface topology of a Ketton carbonate is measured with a nanometer resolution, and a mapped model is constructed with the aid of coarse-grained beads. A surrogate model is presented in which surfaces are represented by two-dimensional sinusoidal functions defined by both an amplitude and a wavelength. The wetting of the reconstructed surface by a fluid, obtained through equilibrium molecular dynamics simulations, is compared to that observed by the different realizations of the surrogate model. A least-squares fitting method is implemented to identify the apparent static contact angle, and the droplet curvature, relative to the effective plane of the solid surface. The apparent contact angle and curvature of the droplet are then used as wetting metrics. The nanoscale contact angle is seen to vary significantly with the surface roughness. In the particular case studied, a variation of over 65° is observed between the contact angle on a flat surface and on a highly spiked (Cassie–Baxter) limit. This work proposes a strategy for systematically studying the influence of nanoscale topography and, eventually, chemical heterogeneity on the wettability of surfaces. Wetting ; Contact angle ; Curvature ; Nanoscopic scale ; Surface roughness ; Surface finish ; Materials science ; Molecular dynamics ; Surface (topology) ; Wetting transition ; Nanotechnology ; Geometry ; Chemistry ; Composite material ; Mathematics Surface Modification and Superhydrophobicity ; Nanopore and Nanochannel Transport Studies ; nanoparticles nucleation surface interactions
Authors: Jing Zhang | Shui Hu | Yi Du | Ding Cao | Guirong Wang | Zhiqin Yuan
Source: Journal of Food and Drug Analysis (review, 2020-12-02)
Field: Chemistry — Analytical Chemistry

Improved food additive analysis by ever-increasing nanotechnology Improper use of food additives may lead to potential threat to human health, making it important to develop sensitive and selective method for their detection. Nanomaterials with unique chemical and electrochemical properties show extensive applications in the design of food additive sensing systems. In this review, we summarize the recently adopted electrochemical and optical analysis of food additives based on nanomaterials. Detection of typical food additives (colorants and preservatives) by using different sensing mechanisms and strategies are provided. In addition, determination of illegal food additives is also briefly introduced. Finally, this review highlights the challenges and future trend of nanomaterial-based food analysis system. Food additive ; Nanomaterials ; Nanotechnology ; Human health ; Biochemical engineering ; Food safety ; Food products ; Preservative ; Risk analysis (engineering) ; Materials science ; Chemistry ; Food science ; Business ; Medicine ; Environmental health ; Engineering Dye analysis and toxicity ; Advanced Chemical Sensor Technologies ; Biochemical Analysis and Sensing Techniques
Authors: Yong X. Gan | Jeremy B. Gan
Source: Journal of Composites Science (article, 2020-06-16)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Advances in Manufacturing Composite Carbon Nanofiber-Based Aerogels This article provides an overview on manufacturing composite carbon nanofiber-based aerogels through freeze casting technology. As known, freeze casting is a relatively new manufacturing technique for generating highly porous structures. During the process, deep cooling is used first to rapidly solidify a well-dispersed slurry. Then, vacuum drying is conducted to sublimate the solvent. This allows the creation of highly porous materials. Although the freeze casting technique was initially developed for porous ceramics processing, it has found various applications, especially for making aerogels. Aerogels are highly porous materials with extremely high volume of free spaces, which contributes to the characteristics of high porosity, ultralight, large specific surface area, huge interface area, and in addition, super low thermal conductivity. Recently, carbon nanofiber aerogels have been studied to achieve exceptional properties of high stiffness, flame-retardant and thermal-insulating. The freeze casting technology has been reported for preparing carbon nanofiber composite aerogels for energy storage, energy conversion, water purification, catalysis, fire prevention etc. This review deals with freeze casting carbon nanofiber composite materials consisting of functional nanoparticles with exceptional properties. The content of this review article is organized as follows. The first part will introduce the general freeze casting manufacturing technology of aerogels with the emphasis on how to use the technology to make nanoparticle-containing composite carbon nanofiber aerogels. Then, modeling and characterization of the freeze cast particle-containing carbon nanofibers will be presented with an emphasis on modeling the thermal conductivity and electrical conductivity of the carbon nanofiber network aerogels. After that, the applications of the carbon nanofiber aerogels will be described. Examples of energy converters, supercapacitors, secondary battery electrodes, dye absorbents, sensors, and catalysts made from composite carbon nanofiber aerogels will be shown. Finally, the perspectives to future work will be presented. Materials science ; Composite number ; Nanofiber ; Carbon nanofiber ; Casting ; Aerogel ; Composite material ; Porosity ; Carbon fibers ; Nanoparticle ; Thermal conductivity ; Ceramic ; Nanotechnology ; Carbon nanotube Supercapacitor Materials and Fabrication ; Aerogels and thermal insulation ; Fiber-reinforced polymer composites
Authors: Nina Mattila | Antti J. Karttunen
Source: Materials Research Express (article, 2020-07-01)
Field: Materials Science — Materials Chemistry

Lattice thermal conductivity of NaCoO<sub>2</sub> and LiCoO<sub>2</sub> intercalation materials studied by hybrid density functional theory Abstract We have studied the lattice dynamics and lattice thermal conductivity of NaCoO 2 intercalation material with first-principles hybrid density functional methods. The lattice thermal conductivity has been obtained using linearized Boltzmann transport theory and the contributions to the lattice thermal conductivity have been analyzed in detail. The results obtained for NaCoO 2 have been systematically compared with LiCoO 2 to shed light on the effect of the alkali metal atom. The room-temperature in-plane lattice thermal conductivities within relaxation time approximation are 78 Wm −1 K −1 and 46 Wm −1 K −1 for NaCoO 2 and LiCoO 2 , respectively. The respective room-temperature cross-plane lattice-thermal conductivities are 25.0Wm −1 K −1 and 6.6 Wm −1 K −1 . The predicted lattice thermal conductivities for fully alkali-occupied single crystals are clearly larger in comparison to the experimental values obtained for single-crystal NaCoO 2 and polycrystalline LiCoO 2 . Analysis of the lattice thermal conductivity reveals that the differences between NaCoO 2 and LiCoO 2 can be explained by significantly shorter phonon lifetimes in LiCoO 2 . Thermal conductivity ; Phonon ; Materials science ; Lattice (music) ; Condensed matter physics ; Crystallite ; Lattice plane ; Thermodynamics ; Reciprocal lattice ; Diffraction ; Composite material ; Physics ; Optics Advanced Thermoelectric Materials and Devices ; Thermal properties of materials ; Thermal Expansion and Ionic Conductivity