jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Jan Elsner | Yucheng Xu | Elliot D. Goldberg | Filip Ivanovic | Aaron Dines | Samuele Giannini | Henning Sirringhaus | Jochen Blumberger
Source: Science Advances (article, 2024-10-23)
Field: Materials Science — Materials Chemistry

Thermoelectric transport in molecular crystals driven by gradients of thermal electronic disorder Thermoelectric materials convert a temperature gradient into a voltage. This phenomenon is relatively well understood for inorganic materials but much less so for organic semiconductors (OSs). These materials present a challenge because the strong thermal fluctuations of electronic coupling between the molecules result in partially delocalized charge carriers that cannot be treated with traditional theories for thermoelectricity. Here, we develop a quantum dynamical simulation approach revealing in atomistic detail how the charge carrier wave function moves along a temperature gradient in an organic molecular crystal. We find that the wave function propagates from hot to cold in agreement with the experiment, and we obtain a Seebeck coefficient in good agreement with experimental measurements that are also reported in this work. Detailed analysis reveals that gradients in thermal electronic disorder play an important role in determining the magnitude of the Seebeck coefficient, opening unexplored avenues for the design of OSs with improved Seebeck coefficients. Seebeck coefficient ; Thermoelectric effect ; Delocalized electron ; Temperature gradient ; Thermoelectric materials ; Condensed matter physics ; Materials science ; Thermal conductivity ; Charge carrier ; Semiconductor ; Thermal ; Work (physics) ; Coupling (piping) ; Charge (physics) ; Chemical physics ; Chemistry ; Physics ; Optoelectronics ; Thermodynamics ; Quantum mechanics Advanced Thermoelectric Materials and Devices ; Molecular Junctions and Nanostructures ; Thermal properties of materials
Authors: Timothy J. Giese | Şölen Ekesan | Erika McCarthy | Yujun Tao | Darrin M. York
Source: Journal of Chemical Theory and Computation (article, 2024-02-17)
Field: Materials Science — Materials Chemistry

Surface-Accelerated String Method for Locating Minimum Free Energy Paths We present a surface-accelerated string method (SASM) to efficiently optimize low-dimensional reaction pathways from the sampling performed with expensive quantum mechanical/molecular mechanical (QM/MM) Hamiltonians. The SASM accelerates the convergence of the path using the aggregate sampling obtained from the current and previous string iterations, whereas approaches like the string method in collective variables (SMCV) or the modified string method in collective variables (MSMCV) update the path only from the sampling obtained from the current iteration. Furthermore, the SASM decouples the number of images used to perform sampling from the number of synthetic images used to represent the path. The path is optimized on the current best estimate of the free energy surface obtained from all available sampling, and the proposed set of new simulations is not restricted to being located along the optimized path. Instead, the umbrella potential placement is chosen to extend the range of the free energy surface and improve the quality of the free energy estimates near the path. In this manner, the SASM is shown to improve the exploration for a minimum free energy pathway in regions where the free energy surface is relatively flat. Furthermore, it improves the quality of the free energy profile when the string is discretized with too few images. We compare the SASM, SMCV, and MSMCV using 3 QM/MM applications: a ribozyme methyltransferase reaction using 2 reaction coordinates, the 2'-<i>O</i>-transphosphorylation reaction of Hammerhead ribozyme using 3 reaction coordinates, and a tautomeric reaction in B-DNA using 5 reaction coordinates. We show that SASM converges the paths using roughly 3 times less sampling than the SMCV and MSMCV methods. All three algorithms have been implemented in the FE-ToolKit package made freely available. Umbrella sampling ; Sampling (signal processing) ; Path (computing) ; String (physics) ; Discretization ; Potential energy surface ; Energy (signal processing) ; Physics ; Range (aeronautics) ; Algorithm ; Computer science ; Mathematics ; Mathematical analysis ; Molecular dynamics ; Quantum mechanics ; Materials science ; Optics ; Molecule Machine Learning in Materials Science ; Protein Structure and Dynamics ; RNA and protein synthesis mechanisms
Authors: Gebru Tesfaye Sherka | Habte Dulla Berry
Source: Frontiers in Physics (article, 2024-08-16)
Field: Materials Science — Materials Chemistry

Insight into impact of size and shape on optoelectronic properties of InX (X = As, Sb, and P) semiconductor nanoparticles: a theoretical study Because of their quantum confinement effects and adjustable features, semiconductor nanoparticles have attracted a lot of attention for their various uses in optoelectronic devices. This study investigates how size and shape variations affect the optoelectronic properties of semiconductor nanoparticles InX (X = As, Sb, and P). Using unified thermodynamics modeling, it explores the effects of these nanoparticles’ diameters on their electronic band structures, optical properties, and charge carrier dynamics. The inquiry focuses on InX nanoparticles with different sizes and nanostructure morphologies. By examining electronic band structures, the density of states, and optical absorption spectra, the size-dependent quantum confinement processes that govern the optical band gap transitions and excitonic behaviors in these semiconductor nanoparticles were made clear. Also, the influence of the shape of the nanoparticles on carrier mobility and electronic band alignment is investigated, offering insights into the possibility of controlling the morphology to customize optoelectronic capabilities. This theoretical analysis indicates that altering the optoelectronic properties of InX semiconductor nanoparticles is mostly dependent on their size and shape. Smaller nanoparticles show stronger quantum size effects, which lead to improved exciton confinement and blue shifts in the optical absorption spectra. Shape-dependent differences in the density of states and electronic band structures indicate the impact of morphology on the dynamics and recombination of charge carriers in the nanoparticles. In conclusion, this work provides important insights for the design and optimization of semiconductor nanomaterials for photovoltaic, sensing, and light-emitting applications by thoroughly examining the impact of size and shape on the optoelectronic properties of InX semiconductor nanoparticles. Semiconductor ; Materials science ; Optoelectronics ; Nanoparticle ; Nanotechnology Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films ; Advanced Semiconductor Detectors and Materials
Authors: Esther Pinilla-Peñalver | Darío Cantero | Amaya Romero | L. Sánchez-Silva
Source: Gels (article, 2024-03-20)
Field: Chemistry — Spectroscopy

Exploring the Impact of the Synthesis Variables Involved in the Polyurethane Aerogels-like Materials Design This research presents a novel approach to synthesising polyurethane (PUR)-based aerogels at the pilot scale, optimizing synthesis variables such as the gelation solvent, solids content, chain extender/isocyanate ratio, and dispersion mode. The solids content (2-11 wt.%) is the parameter with the most influence on the density of the aerogels, with a clear decrease in this property as the solids content decreases. On the other hand, it was demonstrated that minimizing the excess of ethylenediamine (used as chain extender) in relation to the isocyanate is a valuable consideration to improve the thermal conductivity of the aerogel. Related to the chain extender/isocyanate ratio, a compromise situation where the initial isocyanate reacts almost completely is crucial. Fourier-transform infrared spectroscopy was used to conduct such monitoring during the reaction. Once the conditions were optimised, the aerogel showing improved properties was synthesised using ethyl acetate as the gelling solvent, a 3.7 wt.% solids content, an ethylenediamine/isocyanate ratio of 0.20, and sonication as the dispersion mode, attaining a thermal conductivity of 0.030 W m<sup>-1</sup> K<sup>-1</sup> and a density of 0.046 g cm<sup>-3</sup>. Therefore, the synthesized aerogel emerges as a promising candidate for use in the construction and automotive industries. Isocyanate ; Aerogel ; Materials science ; Polyurethane ; Chemical engineering ; Solvent ; Extender ; Fourier transform infrared spectroscopy ; Dispersion (optics) ; Ethylenediamine ; Composite material ; Organic chemistry ; Chemistry Aerogels and thermal insulation ; Advanced Sensor and Energy Harvesting Materials ; Surface Modification and Superhydrophobicity
Authors: Ke Xu | Regina Huang | Xuan Li | Lijian Jin | Chung-Nga Ko | Min Li | Hai Ming Wong | Ken Cham‐Fai Leung
Source: Nanoscale (review, 2024-12-06)
Field: Materials Science — Materials Chemistry

Nanomaterial-based synergistic strategies for combating dental caries: progress and perspectives Dental caries, as the predominant global oral disease, remains a critical public health issue worldwide, particularly in socioeconomically disadvantaged communities. However, common caries prevention approaches (<i>e.g.</i>, oral health education, mechanical plaque removal, and delivery of fluoride agents) are still insufficient for optimal caries management, and therefore, alternative regimens that can supplement existing strategies are highly warranted. Nanomaterials exhibit considerable potential in combating cariogenic pathogens and biofilms owing to their promising antimicrobial capacity, improved penetration into biofilms, targeted precision delivery, and versatile physicochemical properties. As unifunctional materials are limited in caries management, this review underscores the latest advancement in multifunctional anti-caries nanomaterials/nanomedicines. It highlights the cutting-edge materials developed or engineered to (i) incorporate diagnostic capabilities to prevent caries at an early stage, thus enhancing treatment efficiency, (ii) integrate mechanical "brushing" with anti-caries approaches to mechanochemically eradicate biofilms, (iii) exert antimicrobial/antibiofilm effects while preserving dental hard tissue. The current work also outlines future directions for optimizing nanosystems in the management of dental caries while emphasizing the need for innovative solutions to improve preventive and therapeutic efficacies. Nanomaterials ; Nanotechnology ; Materials science Advanced Nanomaterials in Catalysis
Authors: Luis Rangel DaCosta | Katherine Sytwu | Catherine Groschner | Mary Scott
Source: npj Computational Materials (article, 2024-07-29)
Field: Materials Science — Materials Chemistry

A robust synthetic data generation framework for machine learning in high-resolution transmission electron microscopy (HRTEM) Abstract Machine learning techniques are attractive options for developing highly-accurate analysis tools for nanomaterials characterization, including high-resolution transmission electron microscopy (HRTEM). However, successfully implementing such machine learning tools can be difficult due to the challenges in procuring sufficiently large, high-quality training datasets from experiments. In this work, we introduce Construction Zone, a Python package for rapid generation of complex nanoscale atomic structures which enables fast, systematic sampling of realistic nanomaterial structures and can be used as a random structure generator for large, diverse synthetic datasets. Using Construction Zone, we develop an end-to-end machine learning workflow for training neural network models to analyze experimental atomic resolution HRTEM images on the task of nanoparticle image segmentation purely with simulated databases. Further, we study the data curation process to understand how various aspects of the curated simulated data—including simulation fidelity, the distribution of atomic structures, and the distribution of imaging conditions—affect model performance across three benchmark experimental HRTEM image datasets. Using our workflow, we are able to achieve state-of-the-art segmentation performance on these experimental benchmarks and, further, we discuss robust strategies for consistently achieving high performance with machine learning in experimental settings using purely synthetic data. Construction Zone and its documentation are available at https://github.com/lerandc/construction_zone . Computer science ; Workflow ; Machine learning ; Artificial intelligence ; High-resolution transmission electron microscopy ; Python (programming language) ; Segmentation ; Benchmark (surveying) ; Nanotechnology ; Materials science ; Transmission electron microscopy ; Database Machine Learning in Materials Science ; Advanced Electron Microscopy Techniques and Applications ; Electron and X-Ray Spectroscopy Techniques
Authors: Vivek Patel | Pravin Omprakash Sharma | Amit Tiwari | Himanshu Vasnani
Source: Global Journal of Engineering and Technology Advances (article, 2024-10-27)
Field: Materials Science — Biomaterials

Magnesium alloys in the automotive industry: Alloying elements and their impact on material performance This study aims to systematically review and evaluate the application of magnesium (Mg) within the automotive sector, with a focus on enhancing fuel efficiency and supporting environmental sustainability. The review emphasizes the latest advancements in cast magnesium alloys, wrought magnesium alloys, and functional magnesium materials, including the development of novel Mg-based materials. The environmental impact of utilizing magnesium in automotive components is also critically analyzed. Recent innovations, particularly in the fields of nanocomposites and alloying, have significantly enhanced the mechanical properties of magnesium alloys, such as increased strength and improved grain refinement, making them suitable for high-temperature applications. The findings suggest that the competitive pricing and enhanced properties of magnesium and its alloys are key drivers for their widespread adoption in automotive manufacturing. The paper provides a detailed discussion on the current trends in magnesium alloy applications, with particular focus on the role of alloying elements and strategies to address associated challenges. This comprehensive review outlines the recent technological advancements in magnesium materials and their relevance to modern engineering applications in the automotive industry. Automotive industry ; Metallurgy ; Materials science ; Magnesium ; Manufacturing engineering ; Engineering Magnesium Alloys: Properties and Applications ; Material Properties and Applications ; Aluminum Alloys Composites Properties
Authors: Huali Hao | Runan Qin | Cheuk Lun Chow | Denvid Lau
Source: Computer-Aided Civil and Infrastructure Engineering (article, 2024-03-07)
Field: Materials Science — Polymers and Plastics

A multiscale model for wood combustion Understanding wood combustion has become increasingly critical as fire safety engineering moves toward a performance-based approach to building design. Although different kinetic models have been developed for wood burning, chemical kinetics remains a significant challenge for accurate prediction. This work has developed a novel multiscale model by implementing kinetic parameters calculated from molecular dynamics simulations using reactive forcefield into a kinetic model of wood burning. The calculated kinetic parameters of the main components in wood, namely, cellulose, hemicellulose, and lignin, are first utilized to model microscale thermogravimetric experiments for validation. Subsequently, the mesoscale and full-scale fire tests have been simulated by the multiscale model. Furthermore, the fire properties of various wood species at different heat fluxes have been predicted and compared with results from the cone calorimeter test. Our multiscale model outperforms existing kinetic models in predicting wood combustion and can effectively discern the influence of chemical components on fire properties. Microscale chemistry ; Combustion ; Hemicellulose ; Cone calorimeter ; Combustibility ; Kinetic energy ; Lignin ; Thermogravimetric analysis ; Environmental science ; Materials science ; Cellulose ; Chemical engineering ; Chemistry ; Engineering ; Physics Flame retardant materials and properties ; Fire dynamics and safety research ; Thermochemical Biomass Conversion Processes
Authors: С.А. Новиков | Hope A. Long | Aleksandra D. Valueva | Vladislav V. Klepov
Source: Journal of the American Chemical Society (article, 2024-12-10)
Field: Materials Science — Polymers and Plastics

Application of Voronoi Polyhedra for Analysis of Electronic Dimensionality in Emissive Halide Materials The synthesis of new hybrid halide materials is attracting increasing research interest due to their potential optoelectronic applications. However, general design principles that explain and predict their properties are still limited. In this work, we attempted to reveal the role of intermolecular interactions on the optical properties in a series of hybrid halides with an (Et<sub><i>n</i></sub>NH<sub>4-<i>n</i></sub>)<sub>2</sub>Sn<sub>1-<i>x</i></sub>Te<sub><i>x</i></sub>Cl<sub>6</sub> (<i>n</i> = 1-4) composition. DFT calculations showed that the dispersions of the bands involving the Te 5s orbital character gradually decrease as the size of the organic cation increases, indicating a reducing orbital overlap between neighboring TeCl<sub>6</sub><sup>2-</sup> complexes. We characterized the photoluminescence (PL) of the Sn/Te solid solutions in (Et<sub><i>n</i></sub>NH<sub>4-<i>n</i></sub>)<sub>2</sub>Sn<sub>1-<i>x</i></sub>Te<sub><i>x</i></sub>Cl<sub>6</sub> (<i>n</i> = 1-4) phases to correlate the electronic and optical properties. The PL response shows no concentration quenching effects in the (Et<sub>4</sub>N)<sub>2</sub>Sn<sub>1-<i>x</i></sub>Te<sub><i>x</i></sub>Cl<sub>6</sub> series, which demonstrated electronically isolated TeCl<sub>6</sub><sup>2-</sup> complexes. However, the series with smaller organic cations (<i>n</i> = 1-3) and higher electronic dimensionality show concentration quenching effects, which decrease as a function of the Te 5s band dispersions in these compounds. Similar trends can be revealed using a simple semiquantitative electronic dimensionality analysis method by means of Voronoi polyhedra. Since this approach relies only on structural data, it enables rapid characterization of orbital overlap between metal halide complexes in hybrid materials without DFT calculations. The present results allow us to conclude that electronic dimensionality plays an essential role in the photophysical properties of hybrid halide compounds and can be used to fine-tune their properties. Chemistry ; Polyhedron ; Halide ; Voronoi diagram ; Curse of dimensionality ; Chemical physics ; Inorganic chemistry ; Geometry ; Artificial intelligence Transition Metal Oxide Nanomaterials ; Ga2O3 and related materials ; Gas Sensing Nanomaterials and Sensors
Authors: Abosede A. Badeji | Modupe T. Omoniyi | Taofeek B. Ogunbayo | Segun D. Oladipo | Isaac Adebayo Akinbulu
Source: Discover Chemistry. (article, 2024-11-26)
Field: Chemistry — Analytical Chemistry

Quantum chemical investigation of the degradation of acid orange 7 by different oxidants Acid Orange 7 (AO7) is a common azo dye that have found useful application in textile and other industries. However, its toxic and recalcitrant nature presents significant environmental challenges, making it difficult to degrade in wastewater. This study investigates the degradation of AO7 using Density Functional Theory (DFT) calculations, focusing on the structural and electronic properties of AO7 and the effectiveness of different oxidants (H2O2, O3, •OH, SO4•−). Geometry optimization of AO7 was performed using various DFT methods (B3LYP, M06, wB97XD, mPW1PW91, and CAM-B3LYP) with 6-31G(d) and 6-311G(d,p) basis sets. Natural Population Analysis (NPA) revealed significant electron-withdrawing effects of the azo, carbonyl, and sulfonic groups. Additionally, frontier molecular orbital analysis and quantum chemical predictors indicated that O3 will interact well with AO7. However, the •OH was found to be the most effective oxidant, due to its high oxidation potential and low binding energy. The SO4•− also demonstrated strong potential due to its strong interaction and high oxidation potential. While •OH may facilitate faster degradation, oxidants like SO4•− may form more stable complexes with AO7 before initiating degradation. This study highlights the versatility of •OH in degradation processes, providing valuable insights into advanced oxidation processes for environmental remediation. Degradation (telecommunications) ; Quantum chemical ; Orange (colour) ; Chemistry ; Environmental chemistry ; Environmental science ; Organic chemistry ; Computer science ; Molecule ; Telecommunications Dye analysis and toxicity ; Water Quality Monitoring and Analysis ; Electrochemical sensors and biosensors
Authors: Liliya Gimadutdinova | Guzel Ziyatdinova | R. R. Davletshin
Source: Sensors (article, 2024-01-31)
Field: Chemistry — Analytical Chemistry

Voltammetric Sensor Based on the Combination of Tin and Cerium Dioxide Nanoparticles with Surfactants for Quantification of Sunset Yellow FCF Sunset Yellow FCF (SY FCF) is one of the widely used synthetic azo dyes in the food industry whose content has to be controlled for safety reasons. Electrochemical sensors are a promising tool for this type of task. A voltammetric sensor based on a combination of tin and cerium dioxide nanoparticles (SnO<sub>2</sub>-CeO<sub>2</sub> NPs) with surfactants has been developed for SY FCF determination. The synergetic effect of both types of NPs has been confirmed. Surfactants of various natures (sodium lauryl sulfate (SLS), Brij<sup>®</sup> 35, and hexadecylpyridinium bromide (HDPB)) have been tested as dispersive media. The best effects, i.e., the highest oxidation currents of SY FCF, have been observed in the case of HDPB. The sensor demonstrates a 4.5-fold-higher electroactive surface area and a 38-fold-higher electron transfer rate compared to the bare glassy carbon electrode (GCE). The electrooxidation of SY FCF is an irreversible, two-electron, diffusion-driven process involving proton transfer. In differential pulse mode in Britton-Robinson buffer (BRB) pH 2.0, the sensor gives a linear response to SY FCF from 0.010 to 1.0 μM and from 1.0 to 100 μM with an 8.0 nM detection limit. The absence of an interferent effect from other typical food components and colorants has been shown. The sensor has been tested on soft drinks and validated with the standard chromatographic method. Cerium ; Chemistry ; Detection limit ; Electrochemistry ; Electrochemical gas sensor ; Differential pulse voltammetry ; Tin dioxide ; Bromide ; Voltammetry ; Electron transfer ; Bromate ; Nanoparticle ; Antimony ; Nuclear chemistry ; Electrode ; Inorganic chemistry ; Cyclic voltammetry ; Chromatography ; Nanotechnology ; Organic chemistry ; Materials science ; Physical chemistry Dye analysis and toxicity ; Electrochemical Analysis and Applications ; Electrochemical sensors and biosensors