jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Christos Kannas | Amol Thakkar | Esben Jannik Bjerrum | Samuel Genheden
Source: ChemRxiv (preprint, 2022-08-19)
Field: Chemistry — Spectroscopy

rxnutils – A Cheminformatics Python Library for Manipulating Chemical Reaction Data We introduce the Python package rxnutils that can be used to manipulate chemical reactions, reaction templates and reaction datasets. The package is built entirely on open-source software such as RDKit and is designed with robustness, extendibility, and reproducibility in mind. Currently, it consists of three sub-packages one for working with chemical entities, one provides pipelining capabilities, and one provides an end-to-end pipeline for preparing the US patent reaction dataset for modelling. In this software research note we discuss the design of the package and provide some code examples. The project is open-source with a Apache 2.0 license and available at GitHub: https://github.com/MolecularAI/reaction_utils Python (programming language) ; Computer science ; Cheminformatics ; Open source ; Template ; Source code ; Software ; MIT License ; License ; Programming language ; Software engineering ; Open source software ; Robustness (evolution) ; Database ; Computational science ; Operating system ; Chemistry Analytical Chemistry and Chromatography
Authors: Xiangxiang Gao | Haiyang Liu | Jincheng Zhang | Jian Zhu | Jingjing Chang | Yue Hao
Source: Micromachines (article, 2022-06-16)
Field: Materials Science — Materials Chemistry

Thin-Film Transistors from Electrochemically Exfoliated In2Se3 Nanosheets The wafer-scale fabrication of two-dimensional (2D) semiconductor thin films is the key to the preparation of large-area electronic devices. Although chemical vapor deposition (CVD) solves this problem to a certain extent, complex processes are required to realize the transfer of thin films from the growth substrate to the device substrate, not to mention its harsh reaction conditions. The solution-based synthesis and assembly of 2D semiconductors could realize the large-scale preparation of 2D semiconductor thin films economically. In this work, indium selenide (In2Se3) nanosheets with uniform sizes and thicknesses were prepared by the electrochemical intercalation of quaternary ammonium ions into bulk crystals. Layer-by-layer (LbL) assembly was used to fabricate scalable and uniform In2Se3 thin films by coordinating In2Se3 with poly(diallyldimethylammonium chloride) (PDDA). Field-effect transistors (FETs) made from a single In2Se3 flake and In2Se3 thin films showed mobilities of 12.8 cm2·V−1·s−1 and 0.4 cm2·V−1·s−1, respectively, and on/off ratios of >103. The solution self-assembled In2Se3 thin films enriches the research on wafer-scale 2D semiconductor thin films for electronics and optoelectronics and has broad prospects in high-performance and large-area flexible electronics. Materials science ; Thin film ; Semiconductor ; Nanotechnology ; Substrate (aquarium) ; Wafer ; Thin-film transistor ; Chemical vapor deposition ; Flexible electronics ; Indium ; Selenide ; Phosphorene ; Layer (electronics) ; Optoelectronics ; Graphene 2D Materials and Applications ; Perovskite Materials and Applications ; Quantum Dots Synthesis And Properties
Authors: Sheila Hernandez | Lydia Garcia | Martin Perez-Estebañez | William Cheuquepán | Aránzazu Heras | Álvaro Colina
Source: Journal of Electroanalytical Chemistry (article, 2022-06-06)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Multiamperometric-SERS detection of melamine on gold screen-printed electrodes A new, simple and fast protocol to generate gold-based SERS substrates is presented in this work. Melamine is a compound widely used in the industry that can be toxic for humans if consumed even in low concentrations. EC-SERS is an excellent alternative to classical methods to detect and quantify this compound because Raman spectroscopy provides a fingerprint of the molecules, providing very good sensitivity. In this work, time-resolved Raman spectroelectrochemistry is employed to generate a SERS substrate and to detect melamine, all in a single experiment. The dynamic character of this technique provides valuable information about the interaction of the molecule with the generated substrate. An optimization of the spectroelectrochemical method based on a multi-pulse amperometric detection has been performed. The new protocol presented in this work shows significant figures of merit in a very short experiment time, just 25 s. Melamine ; Chemistry ; Substrate (aquarium) ; Raman spectroscopy ; Electrode ; Amperometry ; Figure of merit ; Fingerprint (computing) ; Nanotechnology ; Molecule ; Analytical Chemistry (journal) ; Combinatorial chemistry ; Electrochemistry ; Optoelectronics ; Chromatography ; Materials science ; Organic chemistry ; Optics ; Computer science ; Physical chemistry Gold and Silver Nanoparticles Synthesis and Applications ; Melamine detection and toxicity ; Identification and Quantification in Food
Authors: Alexander N. Bugrov | Yu. E. Gorshkova | Е. М. Иванькова | Г. П. Копица | Alina A. Pavlova | Е. Н. Попова | V. E. Smirnova | R. Yu. Smyslov | В. М. Светличный | Gleb Vaganov | Б.В. Васильев
Source: Polymers (article, 2022-10-03)
Field: Materials Science — Polymers and Plastics

Domain Structure, Thermal and Mechanical Properties of Polycaprolactone-Based Multiblock Polyurethane-Ureas under Control of Hard and Soft Segment Lengths A series of multiblock polyurethane-ureas (PUU) based on polycaprolactone diol (PCL) with a molecular mass of 530 or 2000 g/mol, as well as hard segments of different lengths and structures, were synthesized by the step-growth polymerization method. The chemical structure of the synthesized multiblock copolymers was confirmed by IR- and NMR-spectroscopy. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were used to determine the relaxation and phase transition temperatures for the entire series of the obtained PUU. The X-ray diffraction (XRD) method made it possible to identify PUU compositions in which the crystallizability of soft segments (SS) is manifested due to their sufficient length for self-organization and structuring. Visualization of the crystal structure and disordering of the stacking of SS with an increase in their molecular mobility during heating are shown using optical microscopy. The change in the size of the hard phase domains and the value of the interdomain distance depending on the PCL molecular mass, as well as the length and structure of the hard block in the synthesized PUU, were analyzed using small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS). The evolution of the domain structure upon passing through the melting and crystallization temperatures of PUU soft blocks was studied using SANS. The studies carried out made it possible to reveal the main correlations between the chemical structure of the synthesized PUU and their supramolecular organization as well as thermal and mechanical properties. Small-angle X-ray scattering ; Differential scanning calorimetry ; Materials science ; Glass transition ; Polycaprolactone ; Crystallography ; Thermoplastic polyurethane ; Crystallization ; Phase (matter) ; Chemical engineering ; Polymer chemistry ; Scattering ; Composite material ; Polymer ; Chemistry ; Organic chemistry ; Thermodynamics ; Optics ; Elastomer Polymer composites and self-healing ; Carbon dioxide utilization in catalysis ; Synthesis and properties of polymers
Authors: Yoliria Vázquez‐Martínez | Claudia Angélica Ramírez‐Herrera | Margarita Mondragón | Alex Elı́as-Zúñiga | Luis E. Elizalde
Source: Polymers (article, 2022-12-28)
Field: Materials Science — Materials Chemistry

Effect of Single-Walled Carbon Nanotubes on the Cross-Linking Process in Natural Rubber Vulcanization In this study, the effect of single-walled carbon nanotubes (SWCNTs) on the cross-linking of natural rubber (NR) using organic peroxides was investigated. NR-SWCNTs nanocomposites were prepared in an open two-roller mill followed by vulcanization with the compression molding process. Three different organic peroxides, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane (T29), dicumyl peroxide (DCP), and 2,5-bis(tert-butylperoxy)-2,5-dimethyl-3-hexyne (T145), were used as vulcanizing agents. SWCNTs promote a remarkable reduction in the vulcanization time and increase the degree of cross-linking of vulcanized rubber when compared with neat or natural rubber-carbon-black composites; the same tendency was obtained in the NR-SWCNTs vulcanized with sulfur. Additionally, the mechanical performance of the NR-SWCNTs composites was significantly improved up to 75, 83, 27, and 10% for tensile strength, moduli, tear strength, and hardness. Raman spectroscopy studies evidence the occurrence of reaction between nanotube walls and free radicals generated from using organic peroxides during the vulcanization process. These results demonstrate that the incorporation of SWCNTs in combination with the use of organic peroxides for the NR vulcanization represents a potential alternative for the improvement of the physicochemical properties of NR composites. Vulcanization ; Carbon nanotube ; Materials science ; Natural rubber ; Natural (archaeology) ; Composite material ; Chemical engineering ; Polymer science ; Nanotechnology ; Engineering Carbon Nanotubes in Composites ; Polymer Nanocomposites and Properties ; Tribology and Wear Analysis
Authors: Zhikang Wu | Feifei Li | Xiya Li | Yang Yang | Xiao Huang | Hai Li
Source: Nanomaterials (article, 2022-05-06)
Field: Materials Science — Materials Chemistry

Direct Synthesis of MoS2 Nanosheets in Reduced Graphene Oxide Nanoscroll for Enhanced Photodetection Due to their unique tubular and spiral structure, graphene and graphene oxide nanoscrolls (GONS) have shown extensive applications in various fields. However, it is still a challenge to improve the optoelectronic application of graphene and GONS because of the zero bandgap of graphene. Herein, ammonium tetrathiomolybdate ((NH<sub>4</sub>)<sub>2</sub>MoS<sub>4</sub>) was firstly wrapped into the ((NH<sub>4</sub>)<sub>2</sub>MoS<sub>4</sub>@GONS) by molecular combing the mixture of (NH<sub>4</sub>)<sub>2</sub>MoS<sub>4</sub> and GO solution on hydrophobic substrate. After thermal annealing, the (NH<sub>4</sub>)<sub>2</sub>MoS<sub>4</sub> and GO were converted to MoS<sub>2</sub> nanosheets and reduced GO (RGO) simultaneously, and, thus, the MoS<sub>2</sub>@RGONS was obtained. Raman spectroscopy and high-resolution transmission electron microscopy were used to confirm the formation of MoS<sub>2</sub> nanosheets among the RGONS. The amount of MoS<sub>2</sub> wrapped in RGONS increased with the increasing height of GONS, which is confirmed by the atomic force microscopy and Raman spectroscopy. The as-prepared MoS<sub>2</sub>@RGONS showed much better photoresponse than the RGONS under visible light. The photocurrent-to-dark current ratios of photodetectors based on MoS<sub>2</sub>@RGONS are ~570, 360 and 140 under blue, red and green lasers, respectively, which are 81, 144 and 35 times of the photodetectors based on RGONS. Moreover, the MoS<sub>2</sub>@RGONS-based photodetector exhibited good power-dependent photoresponse. Our work indicates that the MoS<sub>2</sub>@RGONS is expected to be a promising material in the fields of optoelectronic devices and flexible electronics. Graphene ; Photodetection ; Materials science ; Raman spectroscopy ; Photocurrent ; Photodetector ; Optoelectronics ; Oxide ; Nanotechnology ; Band gap ; Transmission electron microscopy ; Nanosheet ; Optics Graphene research and applications ; 2D Materials and Applications ; Advanced Photocatalysis Techniques
Authors: Yi-Hsuan Liu | Sheng Zhang | Puhan Zhang | Ting-Kuo Lee | Gia-Wei Chern
Source: Physical review. B./Physical review. B (article, 2022-07-19)
Field: Materials Science — Materials Chemistry

Machine learning predictions for local electronic properties of disordered correlated electron systems We present a scalable machine learning (ML) model to predict local electronic properties such as on-site electron number and double occupation for disordered correlated electron systems. Our approach is based on the locality principle, or the nearsightedness nature, of many-electron systems, which means local electronic properties depend mainly on the immediate environment. A ML model is developed to encode this complex dependence of local quantities on the neighborhood. We demonstrate our approach using the square-lattice Anderson-Hubbard model, which is a paradigmatic system for studying the interplay between Mott transition and Anderson localization. We develop a lattice descriptor based on the group-theoretical method to represent the on-site random potentials within a finite region. The resultant feature variables are used as input to a multilayer fully connected neural network, which is trained from data sets of variational Monte Carlo (VMC) simulations on small systems. We show that the ML predictions agree reasonably well with the VMC data. Our work underscores the promising potential of ML methods for multiscale modeling of correlated electron systems. Statistical physics ; Hubbard model ; Strongly correlated material ; Monte Carlo method ; Electron ; Scalability ; Artificial neural network ; Lattice (music) ; Locality ; Square lattice ; Computer science ; Electronic structure ; Physics ; Anderson impurity model ; Electronic systems ; Condensed matter physics ; Artificial intelligence ; Mathematics ; Quantum mechanics ; Ising model Machine Learning in Materials Science ; Advanced Chemical Physics Studies ; X-ray Diffraction in Crystallography
Authors: Wenhao Zhang | Ming Lu | Lu Ren | Xiang Zhang | Peng Yang | Ang Li
Source: ChemRxiv (preprint, 2022-07-11)
Field: Chemistry — Organic Chemistry

Reprogramming of the biosynthetic network of Daphniphyllum alkaloids into a chemically synthetic network through generalized biomimetic strategies Biomimetic synthesis is a fundamental approach to the chemical synthesis of natural products, which, due to the intrinsic correlation between the biogenesis and the structure of natural products, offers many advantages. Conventional biomimetic strategies have evolved on a principle featuring “(essentially) the same substrates, similar reactions, and similar pathways”, which defines the pattern of biomimetic synthesis from the structural, mechanistic, and sequential perspectives. In practice, such highly imitative approaches have proved considerably feasible and efficient. However, applicability of this type of approach is also limited by the principle. To enhance the power of biomimetic synthesis, we envision generalized biomimetic strategies focusing on the key bond formation/cleavage sites implied by the biogenesis of natural products, which allow us to take full advantage of altered substrates, reactions, and pathways while retaining the inherent advantages of biomimetic synthesis. In this study, we showcased the utility of generalized biomimetic strategies in the synthesis of fourteen Daphniphyllum alkaloids from the macrodaphniphyllamine, calyciphylline A, daphnilongeranin A, and daphnicyclidin D subfamilies. The biosynthetic network of these alkaloids was reprogrammed into a powerful chemically synthetic network through substrate-, reaction-, and pathway-altering biomimetic strategies. Synthetic biology ; Biomimetic synthesis ; Biogenesis ; Biomimetic materials ; Reprogramming ; Biomimetics ; Nanotechnology ; Combinatorial chemistry ; Biochemical engineering ; Computer science ; Chemistry ; Computational biology ; Biology ; Materials science ; Stereochemistry ; Cell ; Biochemistry ; Engineering Advanced Synthetic Organic Chemistry ; Chemical synthesis and alkaloids ; Synthetic Organic Chemistry Methods
Authors: Ganesh Sivaraman | Gábor Cśanyi | Álvaro Vázquez‐Mayagoitia | Ian Foster | Stephen K. Wilke | Richárd Wéber | Chris J. Benmore
Source: Journal of the Physical Society of Japan (article, 2022-05-10)
Field: Materials Science — Materials Chemistry

A Combined Machine Learning and High-Energy X-ray Diffraction Approach to Understanding Liquid and Amorphous Metal Oxides Determining the structure-property relations of liquid and amorphous metal oxides is challenging, due to their variable short-range order and polyhedral connectivity. To predict chemically realistic structures, we have developed a Machine Learned, Gaussian Approximation Potential (GAP) for HfO2, with a focus on enhanced sampling of the training database and accurate density functional theory calculations. By using training datasets for the GAP model at the level of Density Functional Theory-Strongly Constrained and Appropriately Normed (DFT-SCAN) level of theory, our results show that the topology of both the low viscosity liquid and the amorphous form are dominated by edge-shared chains and small corner-shared rings of polyhedra. This topology is shown to be consistent with the structure of other liquid and amorphous transition metal oxides of variable ion size, such as TiO2 and ZrO2. Current limitations of the ML-GAP modeling method for obtaining glass structures and future perspectives are also discussed. Amorphous solid ; Density functional theory ; Materials science ; Gaussian ; Polyhedron ; Coordination number ; Topology (electrical circuits) ; Diffraction ; Amorphous metal ; Range (aeronautics) ; Statistical physics ; Chemical physics ; Computational chemistry ; Optics ; Crystallography ; Physics ; Ion ; Mathematics ; Geometry ; Quantum mechanics ; Chemistry Machine Learning in Materials Science ; X-ray Diffraction in Crystallography ; Theoretical and Computational Physics
Authors: Yachun Wang | Brandon Miller | Jason Harp | Daniele Salvato | Luca Capriotti | Tiankai Yao
Source: Journal of Nuclear Materials (article, 2022-09-07)
Field: Materials Science — Materials Chemistry

Transmission electron microscopy characterization of the fuel-cladding chemical interactions in HT9 cladded U-10Zr fuel Cladding (metalworking) ; Materials science ; Microstructure ; Grain boundary ; Transmission electron microscopy ; Burnup ; Corrosion ; Metallurgy ; Composite material ; Nuclear engineering ; Nanotechnology Nuclear Materials and Properties ; Nuclear reactor physics and engineering ; Fusion materials and technologies
Authors: Narsimhulu Pittala | Emmelyne Cuza | Dawid Pinkowicz | Michał Magott | Mathieu Marchivie | Kamel Boukheddaden | Smaı̈l Triki
Source: Inorganic Chemistry Frontiers (article, 2022-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Antagonist elastic interactions tuning spin crossover and LIESST behaviours in Fe<sup>II</sup> trinuclear-based one-dimensional chains A new 1-D spin SCO coordination polymer based on Fe II trinuclear units covalently linked by a flexible coligand has been reported as an unusual platform and model system for experimental study on the origin of the step-like feature in 1-D systems. Spin crossover ; Covalent bond ; Crystallography ; Crossover ; Spin (aerodynamics) ; Polymer ; Chemistry ; Materials science ; Condensed matter physics ; Physics ; Nuclear magnetic resonance ; Thermodynamics ; Computer science Magnetism in coordination complexes ; Electron Spin Resonance Studies ; Organic and Molecular Conductors Research
Authors: Samuel Verdú | José Manuel Barat Baviera | Raúl Grau
Source: Journal of Food Engineering (article, 2022-07-09)
Field: Chemistry — Analytical Chemistry

Laser scattering imaging combined with CNNs to model the textural variability in a vegetable food tissue Convolutional neural network ; RGB color model ; Artificial intelligence ; Texture (cosmology) ; Biological system ; Multivariate statistics ; Pattern recognition (psychology) ; Statistical model ; Mathematics ; Food science ; Computer science ; Statistics ; Chemistry ; Image (mathematics) ; Biology Spectroscopy and Chemometric Analyses ; Smart Agriculture and AI ; Meat and Animal Product Quality
Authors: Alistair J. Sterling | Russell C. Smith | Edward A. Anderson | Fernanda Duarte
Source: ChemRxiv (preprint, 2022-03-03)
Field: Chemistry — Organic Chemistry

Beyond strain release: Delocalisation-enabled organic reactivity The release of strain energy is a fundamental driving force for organic reactions. However, strain release alone is an insufficient predictor of reactivity, as seen in the equivalent strain energies but disparate reactivity of cyclopropane and cyclobutane. Here we show that bond delocalisation is a key factor that operates alongside strain release to boost and even dominate reactivity, significantly lowering the energy required for bond-breaking in cyclopropanes and cycloalkynes. Thermodynamic and delocalisation parameters explain the relative reaction rates of molecules containing these functional groups, leading to a ‘rule-of-thumb’ that accurately predicts activation barriers. These principles are demonstrated in the context of the reactions of strained building blocks commonly encountered in organic synthesis, medicinal chemistry, polymer science and bioconjugation. By introducing delocalisation as a means to control reactivity profiles, these findings will transform the use of strain as a design concept in synthesis. Reactivity (psychology) ; Strain (injury) ; Context (archaeology) ; Cyclobutane ; Cyclopropane ; Chemistry ; Computational chemistry ; Organic synthesis ; Combinatorial chemistry ; Organic chemistry ; Catalysis Cyclopropane Reaction Mechanisms ; Synthetic Organic Chemistry Methods ; Catalytic Alkyne Reactions