jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Zhenghan Zhang | Cong Lin | Jian Li
Source: Small Methods (review, 2024-11-27)
Field: Chemistry — Inorganic Chemistry

Utilization of Three‐Dimensional Electron Diffraction for Structure Determination of Extra‐Large‐Pore Zeolites The development of extra-large-pore (ELP) zeolites is crucial for industries of petrochemical catalysis, notably in processes like diesel cracking and hydrocracking of multi-carbon hydrocarbon substrates. The catalytic performance and selectivity of these zeolites depend heavily on their specific porous structures, making precise structure determination highly essential for understanding their properties and functionalities. However, the complex structures of ELP zeolites pose significant challenges for characterization. Three-dimensional electron diffraction (3DED) has emerged as a leading technique for studying zeolites as it does not require large crystals or pure samples. This review provides an overview of the development and application of 3DED for elucidating ELP zeolite structures. It begins with a summary of zeolites and their structural determination methods, followed by a detailed discussion of the principles and benefits of 3DED, the ELP zeolites discovered to date, and the specific applications and findings by 3DED. Additionally, the review anticipates that combining 3DED with other advanced techniques will enhance the understanding of ELP zeolites, including aspects like heteroatom doping, host-guest interactions, framework flexibility, and detailed structural characterization. This integration is expected to lead to innovations in the development and application of ELP zeolites. Characterization (materials science) ; Zeolite ; Heteroatom ; Nanotechnology ; Materials science ; Fluid catalytic cracking ; Petrochemical ; Porosity ; Catalysis ; Cracking ; Chemical engineering ; Chemistry ; Organic chemistry ; Engineering Zeolite Catalysis and Synthesis ; Mesoporous Materials and Catalysis ; Metal-Organic Frameworks: Synthesis and Applications
Authors: Erendra Manandhar | Blake O. Day | Ke ́shay M. Sampson | Evelyn E. Schroeder | Aimee L. Ninahaza | Samantha T. Aragon | Camille J. Kwan | Franchesca C. Tinacba | J. Joshua | Rosanna Jees | Ram S. Bhatta | Peter J. Cragg
Source: Journal of Fluorescence (article, 2024-07-27)
Field: Chemistry — Spectroscopy

A 1,8-Naphthalimide-based Tripodal Fluorescent Chemosensor to Selectively Detect Copper Ions Chemistry ; Detection limit ; Acetonitrile ; Fluorophore ; Binding constant ; Fluorescence ; Copper ; Cycloaddition ; Metal ions in aqueous solution ; Ligand (biochemistry) ; Alkyne ; Click chemistry ; Photochemistry ; Azide ; Aqueous solution ; Stoichiometry ; Metal ; Combinatorial chemistry ; Physical chemistry ; Organic chemistry ; Binding site ; Catalysis Molecular Sensors and Ion Detection ; Advanced biosensing and bioanalysis techniques ; Click Chemistry and Applications
Authors: Jian‐Ge Zhou | Yinan Shu | Yuchen Wang | Jerzy Leszczyński | Oleg V. Prezhdo
Source: The Journal of Physical Chemistry Letters (article, 2024-02-09)
Field: Chemistry — Spectroscopy

Dissociation Time, Quantum Yield, and Dynamic Reaction Pathways in the Thermolysis of <i>trans</i>-3,4-Dimethyl-1,2-dioxetane The thermolysis of <i>trans</i>-3,4-dimethyl-1,2-dioxetane is studied by trajectory surface hopping. The significant difference between long and short dissociation times is rationalized by frustrated dissociations and the time spent in triplet states. If the C-C bond breaks through an excited state channel, then the trajectory passes over a ridge of the potential energy surface of that state. The calculated triplet quantum yields match the experimental results. The dissociation half-times and quantum yields follow the same ascending order as per the product states, justifying the conjecture that the longer dissociation time leads to a higher quantum yield, proposed in the context of the methylation effect. The populations of the molecular Coulomb Hamiltonian and diagonal states reach equilibrium, but the triplet populations with different S<sub><i>z</i></sub> components fluctuate indefinitely. Certain initial velocities, leading the trajectories to given product states, can be identified as the most characteristic features for sorting trajectories according to their product states. Dissociation (chemistry) ; Chemistry ; Quantum yield ; Excited state ; Potential energy surface ; Quantum ; Singlet state ; Triplet state ; Potential energy ; Atomic physics ; Hamiltonian (control theory) ; Quantum mechanics ; Physics ; Physical chemistry ; Molecule ; Mathematics ; Fluorescence Mass Spectrometry Techniques and Applications ; Photoreceptor and optogenetics research ; Hemoglobin structure and function
Authors: David Bowskill | Benjamin I. Tan | Adam C. Keates | Isaac J. Sugden | Claire S. Adjiman | Constantinos C. Pantelides
Source: Journal of Chemical Theory and Computation (article, 2024-11-12)
Field: Materials Science — Materials Chemistry

Large-Scale Parameter Estimation for Crystal Structure Prediction. Part 1: Dataset, Methodology, and Implementation Crystal structure prediction (CSP) seeks to identify all thermodynamically accessible solid forms of a given compound and, crucially, to establish the relative thermodynamic stability between different polymorphs. The conventional hierarchical CSP workflow suggests that no single energy model can fulfill the needs of all stages in the workflow, and energy models across a spectrum of fidelities and computational costs are required. Hybrid <i>ab initio</i>/empirical force-field (HAIEFF) models have demonstrated a good balance of these two factors, but the force-field component presents a major bottleneck for model accuracy. Existing parameter estimation tools for fitting this empirical component are inefficient and have severe limitations on the manageable problem size. This, combined with a lack of reliable reference data for parameter fitting, has resulted in development in the force-field component of HAIEFF models having mostly stagnated. In this work, we address these barriers to progress. First, we introduce a curated database of 755 organic crystal structures, obtained using high quality, solid-state DFT-D calculations, which provide a complete set of geometry and energy data. Comparisons to various theoretical and experimental data sources indicate that this database provides suitable diversity for parameter fitting. In tandem, we also put forward a new parameter estimation algorithm implemented as the CrystalEstimator program. Our tests demonstrate that CrystalEstimator is capable of efficiently handling large-scale parameter estimation problems, simultaneously fitting as many as 62 model parameters based on data from 445 structures. This problem size far exceeds any previously reported works related to CSP force-field parametrization. These developments form a strong foundation for all future work involving parameter estimation of transferable or tailor-made force-fields for HAIEFF models. This ultimately opens the way for significant improvements in the accuracy achieved by the HAIEFF models. Scale (ratio) ; Computer science ; Estimation ; Data mining ; Crystal structure prediction ; Crystal structure ; Cartography ; Systems engineering ; Engineering ; Geography ; Chemistry ; Crystallography X-ray Diffraction in Crystallography ; Crystallization and Solubility Studies ; Machine Learning in Materials Science
Authors: F. Esposito | Matteo Bosi | G. Attolini | Francesca Rossi | R. Fornari | Filippo Fabbri | L. Seravalli
Source: Nanomaterials (article, 2024-10-31)
Field: Materials Science — Materials Chemistry

Influence of the Carrier Gas Flow in the CVD Synthesis of 2-Dimensional MoS2 Based on the Spin-Coating of Liquid Molybdenum Precursors Atomically thin molybdenum disulfide (MoS<sub>2</sub>) is a two-dimensional semiconductor with versatile applications. The recent adoption of liquid molybdenum precursors in chemical vapor deposition has contributed significantly to the reproducible wafer-scale synthesis of MoS<sub>2</sub> monolayer and few-layer films. In this work, we study the effects of the carrier gas flow rate on the properties of two-dimensional molybdenum disulfide grown by liquid-precursor-intermediate chemical vapor deposition on SiO<sub>2</sub>/Si substrates. We characterized the samples using Optical Microscopy, Scanning Electron Microscopy, Raman spectroscopy, and Photoluminescence spectroscopy. We analyzed samples grown with different nitrogen carrier flows, ranging from 150 to 300 sccm, and discussed the effect of carrier gas flows on their properties. We found a correlation between MoS<sub>2</sub> flake lateral size, shape, and number of layers, and we present a qualitative growth model based on changes in sulfur provision caused by different carrier flows. We show how the use of liquid precursors can allow for the synthesis of homogeneous, single-layer flakes up to 100 µm in lateral size by optimizing the gas flow rate. These results are essential for gaining a deeper understanding of the growth process of MoS<sub>2</sub>. Molybdenum ; Materials science ; Coating ; Flow (mathematics) ; Chemical engineering ; Spin coating ; Spin (aerodynamics) ; Nanotechnology ; Metallurgy ; Mechanics ; Physics ; Thermodynamics ; Engineering 2D Materials and Applications ; MXene and MAX Phase Materials ; Ferroelectric and Negative Capacitance Devices
Authors: Anu Vashishtha | Anthony Phimphachanh | Thomas Gaillard | Julien Schmitt | Corine Gérardin | Gaulthier Rydzek | Tangi Aubert
Source: ACS Nano (article, 2024-10-13)
Field: Materials Science — Materials Chemistry

Hybrid Silica Cage-Type Nanostructures Made from Triply Hydrophilic Block Copolymers Single Micelles Controlling the structure and functionality of porous silica nanoparticles has been a continuous source of innovation with important potential for advanced biomedical applications. Their synthesis, however, usually involves passive surfactants or amphiphilic copolymers that do not add value to the material after synthesis. In contrast, polyion complex (PIC) micelles based on hydrophilic block copolymers allow for the direct synthesis of intrinsically functional hybrid materials. While most previous studies have focused on bulk materials made from double-hydrophilic block copolymers (DHBC), in this work we have synthesized a triple-hydrophilic block copolymer (THBC) and demonstrated both its PIC micellization and its potential for hybrid mesoporous silica nanomaterials. Introducing this THBC has allowed to direct the transition from bulk three-dimensional (3D) materials to zero-dimensional (0D) nanomaterials with cage-type structures. The stabilization and isolation of these nanostructures formed around discrete individual micelles has been made possible by the careful design of the three different blocks that each play a key role. These nanostructures could also be synthesized from hybrid PIC micelles based on THBC-multivalent metal ions complexes, offering a direct route to metal/silica composite nanoparticles. This class of THBC polymers therefore creates significant opportunities for the synthesis of nanostructures with complex and functional architectures. Micelle ; Materials science ; Copolymer ; Nanomaterials ; Nanostructure ; Template ; Nanoparticle ; Amphiphile ; Nanotechnology ; Hybrid material ; Polymer ; Self-assembly ; Mesoporous material ; Chemical engineering ; Chemistry ; Organic chemistry ; Composite material Mesoporous Materials and Catalysis ; Polyoxometalates: Synthesis and Applications ; Nanoparticle-Based Drug Delivery
Authors: Xin Liu | Yufeng Lin | Yu Li | Nian Liu
Source: Materials (article, 2024-02-08)
Field: Materials Science — Materials Chemistry

Effect of Bi on the Performance of Al-Ga-In Sacrificial Anodes Cathodic protection is widely used for metal corrosion protection. To improve their performance, it is necessary and urgent to study the influence of metal oxides on the microstructure and performance of aluminum alloy sacrificial anodes. Taking an Al-Ga-In sacrificial anode as the research object, the dissolution morphology and current efficiency characteristics were studied by means of electrochemical testing and microstructural observation, and the influence of varying Pb and Bi contents on the performance of an aluminum alloy sacrificial anode was investigated. The test results reveal that: (1) The Al-Ga-In sacrificial anode with 4% Pb and 1% Bi contents exhibits the best sacrificial anode performance. (2) The inclusion of an appropriate Bi element content shifts the open-circuit potential in a negative direction and promotes activation dissolution. Conversely, excessive Bi content leads to uneven dissolution, resulting in the shedding of anode grains and greatly reducing the current efficiency. (3) During the activation dissolution of the aluminum alloy, the second phase preferentially dissolves, and the activation point destroys the oxide film, resulting in the dissolution of the exposed aluminum matrix. Consequently, the concentration of dissolved metal ions is reduced and deposited back on the surface of the anode sample, promoting the continuous dissolution of the anode. Materials science ; Anode ; Dissolution ; Galvanic anode ; Alloy ; Oxide ; Metallurgy ; Microstructure ; Cathodic protection ; Aluminium ; Corrosion ; Electrochemistry ; Chemical engineering ; Electrode ; Chemistry Corrosion Behavior and Inhibition ; Recycling and Waste Management Techniques ; Concrete Corrosion and Durability
Authors: Uzma Arshad | Nusrat Shafiq | Shagufta Parveen | Maryam Rashid
Source: Future Medicinal Chemistry (article, 2024-09-12)
Field: Chemistry — Organic Chemistry

Discovery of novel dihydro-pyrimidine hybrids: insight into the design, synthesis, biological evaluation and absorption, distribution, metabolism and excretion studies <b>Aim:</b> By keeping in aspects, the pharmacological potential of heterocyclic compounds, pyrimidine-based compounds were designed, synthesized and evaluated for α-amylase inhibitory potential.<b>Materials & methods:</b> Five new series 1a-l, 2a-d, 3a-d, 4a-d and 5a-d of 1,2,3,4-tetrahydroprimidine-5-carboxylate derivatives were designed by <i>de novo</i> method by taking Alogliptin as reference compound. Here in we describe synthesis and characterization of compounds as potential α-amylase inhibitor.<b>Results:</b> Structure activity relationship (SAR), <i>in vitro</i> analysis and molecular modelling approaches generate compounds <b>1 h, 1i, 1k</b> and <b>4c</b> as potential lead with good α-amylase inhibitory selection. However, compound <b>1k</b> failed the criteria of optimization as drug lead by ADME studies while all other compounds showed optimum range for all <i>in silico</i> ADME parameters.<b>Conclusion:</b> Therefore, these compounds can serve as potential lead candidate in developing anti-diabetic therapy. Pyrimidine ; Excretion ; Absorption (acoustics) ; ADME ; Chemistry ; Distribution (mathematics) ; Metabolism ; Biochemistry ; Pharmacology ; Biology ; Materials science ; In vitro ; Mathematics Synthesis and biological activity ; Biochemical and Molecular Research ; Quinazolinone synthesis and applications
Authors: Roberto Brighenti | Mattia Pancrazio Cosma | Silvia Monchetti
Source: European Journal of Mechanics - A/Solids (article, 2024-04-14)
Field: Chemistry — Organic Chemistry

Mechanics of polymers obtained by layered photopolymerization The photopolymerization process is a high-precision and efficient technology to obtain solid polymers starting from a photosensible liquid resin made of monomer units. This technology is widely used in additive manufacturing to produce objects whose size can fall within the range m. The outstanding potentialities of this technology can be harnessed to tailor the structure of a polymeric material by controlling how the light-induced polymerization process is performed, typically by operating on subsequent layers forming the final object. The present research illustrates the chemical-physics phenomena involved in the photopolymerization and presents a multi-physics framework and the related governing equations. Its implementation within a computational framework is developed and several simulations demonstrating the influence of the AM printing setup on the final microstructure of the obtained polymer are presented. It is shown that photopolymerization-based AM technology allows us to finely tune the mechanical properties distribution within the material domain, enabling the material’s architecture to be tailored to the application of interest. Photopolymer ; Polymer ; Polymerization ; Materials science ; Process (computing) ; Monomer ; Nanotechnology ; Computer science ; Polymer science ; Composite material Photopolymerization techniques and applications ; Additive Manufacturing and 3D Printing Technologies ; Advanced Polymer Synthesis and Characterization
Authors: Omar M. Atrooz | Makarem Al-Awaida | Wajdy Al‐Awaida | Hamzeh J. Al‐Ameer | Hamdi Uysal
Source: Advancements in Life Sciences (article, 2024-10-22)
Field: Materials Science — Biomaterials

Evaluating the Antioxidant Capacity, Phenolic Contents, and Anticancer Potential of Caralluma europaea Extracts Background: Caralluma europaea (C. europaea) is a genus of shrubs in the Apocynaceae family, endemic to the Mediterranean region. Assessing the anticancer properties, total phenolic and flavonoid content, and antioxidant activity of different C. europaea extracts were the aim of this study.Methods: To determine antioxidant activity, we used three free radical scavenging assays: DPPH (2,2-Diphenyl-1-picrylhydrazyl), hydrogen peroxide (H2O2), and nitric oxide (NO) assays. Total phenolic and flavonoid contents were measured using colorimetric methods. The anti-important activity was evaluated by MTT assay.Results: Our findings showed that the efficacy of the extract in MCF7 cells decreased in the system containing chloroform, methanol, ethyl acetate, and water. The strength of the extract for U87 cells decreased according to methanolic, chloroform and water, where ethyl acetate was the strongest. The highest total phenolic and flavonoid content was found in methanol extract. All extracts showed a high scavenging activity of DPPH. Methanol extract showed the highest antioxidant activity in the NO assay of the solution, followed by ethyl acetate, chloroform, and aqueous extract. In the H2O2-based antioxidant activity assay, the methanol extract again showed the highest activity, followed by ethyl acetate, chloroform, and aqueous extracts.Conclusions: Extracts of C. europaea have shown great potential as natural antioxidants and anticancer agents in this study, suggesting that they deserve further investigation into the food and pharmaceutical fields.Keywords: Phenolic content; Flavonoid content; Antioxidant activity; Anti-cancer activity Antioxidant capacity ; Antioxidant ; Traditional medicine ; Chemistry ; Botany ; Biology ; Biochemistry ; Medicine Phytochemistry and Bioactive Compounds ; Phytochemistry and Biological Activities ; Fungal Biology and Applications
Authors: Yvonne Achieng Ouma | Supriti Sundari Nayak | Harekrishna Panigrahi | Smrutirekha Mishra
Source: JOURNAL OF POLYMER MATERIALS (article, 2024-01-01)
Field: Materials Science — Biomaterials

Bio-Nanocomposites Based on Polyvinyl Alcohol and Fuller Earth Nanoclay: Preparation, Properties and Its Application in Food Packaging Fuller earth (FE) nanoclay is a naturally occurring mineral with a high surface area, is highly abundant, and has a low purchasing cost, making it an excellent candidate for nanocomposite production. The study highlights the ... | Find, read and cite all the research you need on Tech Science Press Polyvinyl alcohol ; Nanocomposite ; Materials science ; Food packaging ; Nanotechnology ; Composite material ; Chemistry ; Food science biodegradable polymer synthesis and properties
Authors: Ghada Tagorti | Burçin Yalçın | Merve Güneş | Ayşen Yağmur Burgazlı | Tuğçe Kuruca | Neslihan Cihanoğlu | Esin Akarsu | Nuray Kaya | Ricard Marcos | Bülent Kaya
Source: Journal of Hazardous Materials (article, 2024-01-10)
Field: Chemistry — Organic Chemistry

Alcohol-free synthesis, biological assessment, in vivo toxicological evaluation, and in silico analysis of novel silane quaternary ammonium compounds differing in structure and chain length as promising disinfectants Quaternary ammonium compounds (QACs) are commonly used as disinfectants for industrial, medical, and residential applications. However, adverse health outcomes have been reported. Therefore, biocompatible disinfectants must be developed to reduce these adverse effects. In this context, QACs with various alkyl chain lengths (C12-C18) were synthesized by reacting QACs with the counterion silane. The antimicrobial activities of the novel compounds against four strains of microorganisms were assessed. Several in vivo assays were conducted on Drosophila melanogaster to determine the toxicological outcomes of Si-QACs, followed by computational analyses (molecular docking, simulation, and prediction of skin sensitization). The in vivo results were combined using a cheminformatics approach to understand the descriptors responsible for the safety of Si-QAC. Si-QAC-2 was active against all tested bacteria, with minimal inhibitory concentrations ranging from 13.65 to 436.74 ppm. Drosophila exposed to Si-QAC-2 have moderate-to-low toxicological outcomes. The molecular weight, hydrophobicity/lipophilicity, and electron diffraction properties were identified as crucial descriptors for ensuring the safety of the Si-QACs. Furthermore, Si-QAC-2 exhibited good stability and notable antiviral potential with no signs of skin sensitization. Overall, Si-QAC-2 (C14) has the potential to be a novel disinfectant. In silico ; Chemistry ; Silane ; Ammonium ; In vivo ; Alcohol ; Organic chemistry ; Biotechnology ; Biochemistry ; Biology Antimicrobial agents and applications ; Biopolymer Synthesis and Applications ; Chemical Analysis and Environmental Impact
Authors: Radost Herboth | Alexander P. Lyubartsev
Source: ACS Omega (article, 2024-08-15)
Field: Materials Science — Materials Chemistry

Exploring Carbamazepine Polymorph Crystal Growth in Water by Enhanced Sampling Simulations In this work, the polymorphism of the active pharmaceutical ingredient carbamazepine (CBZ) was investigated by using molecular dynamics simulations with an enhanced sampling scheme. A single molecule of CBZ attaching to flat surfaces of different polymorphs was used as a model for secondary nucleation in water. A novel approach was developed to compute the free energy profile characterizing the adsorption of molecules with orientation aligned with the crystal structure of the surface. The distribution of states that showed alignment was used to rescale the adsorption free energy to include only the contribution that is consistent with crystal growth. The resulting free energy surfaces showed favorable thermodynamics for the most stable form, Form III and the second most stable form, Form I. The primary crystallization product, a dihydrate, was found to be less favorable, implying a nonclassical crystallization pathway. We suggest that a major contribution determining the energetics is the hydrophobicity of the surface. This thermodynamic ranking provides valuable information about the molecular pathways of polymorph growth and will further contribute to the understanding of the crystallization process of CBZ, which is imperative since polymorph formation can alter the physical properties of a drug significantly. Crystallization ; Nucleation ; Polymorphism (computer science) ; Molecule ; Adsorption ; Molecular dynamics ; Crystal (programming language) ; Crystal growth ; Thermodynamics ; Umbrella sampling ; Chemical physics ; Chemistry ; Surface energy ; Crystallography ; Materials science ; Computational chemistry ; Physical chemistry ; Organic chemistry Crystallization and Solubility Studies ; Analytical Chemistry and Chromatography ; Surfactants and Colloidal Systems