jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: François Duprat | Jean-Luc Ploix | Gérard Dreyfus
Source: Molecules (article, 2024-07-01)
Field: Chemistry — Spectroscopy

Can Graph Machines Accurately Estimate 13C NMR Chemical Shifts of Benzenic Compounds? In the organic laboratory, the <sup>13</sup>C nuclear magnetic resonance (NMR) spectrum of a newly synthesized compound remains an essential step in elucidating its structure. For the chemist, the interpretation of such a spectrum, which is a set of chemical-shift values, is made easier if he/she has a tool capable of predicting with sufficient accuracy the carbon-shift values from the structure he/she intends to prepare. As there are few open-source methods for accurately estimating this property, we applied our graph-machine approach to build models capable of predicting the chemical shifts of carbons. For this study, we focused on benzene compounds, building an optimized model derived from training a database of 10,577 chemical shifts originating from 2026 structures that contain up to ten types of non-carbon atoms, namely H, O, N, S, P, Si, and halogens. It provides a training root-mean-squared relative error (RMSRE) of 0.5%, i.e., a root-mean-squared error (RMSE) of 0.6 ppm, and a mean absolute error (MAE) of 0.4 ppm for estimating the chemical shifts of the 10k carbons. The predictive capability of the graph-machine model is also compared with that of three commercial packages on a dataset of 171 original benzenic structures (1012 chemical shifts). The graph-machine model proves to be very efficient in predicting chemical shifts, with an RMSE of 0.9 ppm, and compares favorably with the RMSEs of 3.4, 1.8, and 1.9 ppm computed with the ChemDraw v. 23.1.1.3, ACD v. 11.01, and MestReNova v. 15.0.1-35756 packages respectively. Finally, a Docker-based tool is proposed to predict the carbon chemical shifts of benzenic compounds solely from their SMILES codes. Chemical shift ; Carbon-13 NMR ; Graph ; Computer science ; Chemistry ; Computational chemistry ; Physical chemistry ; Organic chemistry ; Theoretical computer science Molecular spectroscopy and chirality ; Metabolomics and Mass Spectrometry Studies ; Computational Drug Discovery Methods
Authors: Mourad Termoul | Salima Attouti | Mokhtar Benzekri Benallou | Anissa Zerhouni | Tuğba Uğur | Murat Tuna | N. Benderdouche | Benaouda Bestani
Source: STUDIES IN ENGINEERING AND EXACT SCIENCES (article, 2024-06-28)
Field: Chemistry — Organic Chemistry

Synthesis and characterization of ZnO/activated carbon nanocomposite for the removal of cationic dye from aqueous solutions In this work, we focused on the modification and characterization of activated carbon supported by ZnO nanoparticles. Our study was based on the modification process involving the synthesis of two types of modified activated carbon using metallic nanoparticles, each following different protocols. Secondly, we concentrated on characterization methods such as the methylene blue index, the iodine value, the determination of the point of zero charge, infrared analysis, and the application of adsorption for methylene blue. The adsorbent with the highest iodine number has the largest specific surface area; in this case, it is the ZnO-AC from protocol 2, with an iodine number of 1145.11 mg.g-1 for activated carbon modified with ZnO nanoparticles. The total amount of surface acidic groups of the modified activated carbon increased after modification, contrary to the commercial activated carbon. These results are confirmed by pHzpc and FT-IR analyses of the activated carbon studied. The pHzpc for all the activated carbons studied is lower than the pH of the aqueous solution, indicating they have more acidic surfaces. The adsorption results of methylene blue showed that the activated carbon modified in protocol two was the more efficient one but couldn’t exceed the commercial efficiency. The non-linear regression analysis method showed that the methylnene blue adsorption data followed Temkin's isothermal model rather than that of Langmuir and Freundlich.. The adsorption capacities for nanocomposite from protocol 1 and the Merck activated carbon are 610.23 mg.g-1 and 553.03 mg.g-1, respectively. These values indicate that our activated carbon produced in the laboratory has a strong adsorption of methylene blue on Merck and modified activated carbon is probably due to increased porosity. The study confirms that activated carbon doped with ZnO nanoparticles can be useful for eliminating methylene blue in aqueous solution. Cationic polymerization ; Nanocomposite ; Characterization (materials science) ; Aqueous solution ; Activated carbon ; Chemical engineering ; Materials science ; Chemistry ; Polymer chemistry ; Nanotechnology ; Organic chemistry ; Adsorption Synthesis of Tetrazole Derivatives ; Water Quality Monitoring and Analysis
Authors: Samriti Vaid | Varinder Kaur | Sanyog Sharma | Anupinder Singh | Bhavna Vaid | Raj Kumar Arya | George D. Verros
Source: Journal of Engineering (article, 2024-01-01)
Field: Materials Science — Biomaterials

Utilizing Local Waste: Sustainable Adsorption of Reactive Blue 235 on Surfactant‐Modified Bamboo Fibers In this research endeavor, we sought to enhance the efficacy of bamboo fibers through modification with the surfactant cetyltrimethylammonium bromide (CTAB) for the purpose of removing Reactive Blue 235 from effluent. Our investigation encompassed a comprehensive exploration of the impact of crucial parameters, namely, adsorbent dosage (0.25 g–1.25 g), contact time (10–80 min), pH (2–12), initial dye concentration (20–100 mg/L), and temperature (298 K, 308 K, and 318 K) on the dynamics of dye removal. The optimum dye removal efficiency of 94% for Reactive Blue 235 was obtained at an adsorbent dosage of 0.5 g/50 ml of dye solution, initial dye concentration of 40 mg/L, pH of 6, and contact time of 40 min. The experimental framework included the anticipation of data aligned with various isothermal and kinetic models, facilitating a nuanced understanding of the adsorption process. Our findings unveiled that the kinetics of adsorption adhered to a second‐order model, while the Langmuir isotherm model aptly described the adsorption behavior. Particularly noteworthy was the monolayer’s adsorption capacity, quantified at an impressive 7.39 mg·g −1 at a temperature of 318 K. The value of Freundlich’s constant, K F , increases with an increase in temperature indicating the endothermic nature of adsorption. The magnitude of E obtained from Dubinin–Radushkevich isotherm varying from 3.92 to 4.66 kJ/mol on increasing temperature from 298 K to 318 K suggests that adsorption of RB235 on BAT is a physisorption (value of E is between 1 and 8 kJ/mol). Delving into the thermodynamic aspects of the process, we calculated Δ H and Δ S to be 54.88 kJ/mol and 184.54 J/mol/K, respectively. The consistently negative values of Δ G (between −0.183 kJ/mol and −3.884 kJ/mol) at all temperatures underscored the feasibility, spontaneity, and entropy‐driven nature of the adsorption of RB235 on CTAB‐treated bamboo fiber (BAT). What sets our study apart is the deliberate utilization of bamboo fibers sourced from local waste streams, embodying a commitment to sustainable practices. Beyond its effectiveness in effluent treatment, our approach aligns with eco‐friendly principles by repurposing indigenous waste materials, contributing to a more sustainable and environmentally responsible future. Bamboo ; Adsorption ; Pulmonary surfactant ; Reactive dye ; Chemical engineering ; Waste management ; Chemistry ; Pulp and paper industry ; Materials science ; Composite material ; Organic chemistry ; Dyeing ; Engineering Advanced Cellulose Research Studies ; Adsorption and biosorption for pollutant removal
Authors: Karthik Sankaranarayanan | Klavs F. Jensen
Source: Chemical Science (article, 2024-01-01)
Field: Chemistry — Spectroscopy

Similarity based functionalization for enumeration of synthetically plausible chemical libraries surrounding a target Functionalization of lead compounds to create analogs is a challenging step in discovering new molecules with desired properties and it is conducted throughout the chemical industry, including pharmaceuticals and agrochemicals. The process can be time-consuming and expensive, requiring expert intuition and experience. To help address synthesis planning challenges in late-stage functionalization, we have developed a molecular similarity approach that proposes single-step functionalization reactions based on analogy to precedent reactions. The developed approach mimics reaction strategies and suggests co-reactants defined implicitly by a corpus of known reactions. Using <i>ca.</i> 348 k reactions from the patent literature as a knowledge base, the recorded products or close analogs are among the top 20 proposed products in 74% of ∼44 k test reactions. The combinatorial growth inherent in recursive applications of the tool allows the enumeration of chemical libraries surrounding a target compound of interest. Moreover, each step of the resulting library synthesis leverages common chemical transformations reported in the literature accessible to most chemists. Enumeration ; Similarity (geometry) ; Surface modification ; Computer science ; Artificial intelligence ; Combinatorial chemistry ; Chemistry ; Mathematics ; Combinatorics Analytical Chemistry and Chromatography ; Computational Drug Discovery Methods ; Chemical Synthesis and Analysis
Authors: A. C. Trindade
Source: Polymers (review, 2024-06-27)
Field: Materials Science — Materials Chemistry

Controlled Surface Textures of Elastomeric Polyurethane Janus Particles: A Comprehensive Review Colloidal particle research has witnessed significant advancements in the past century, resulting in a plethora of studies, novel applications, and beneficial products. This review article presents a cost-effective and low-tech method for producing Janus elastomeric particles of varied geometries, including planar films, spherical particles, and cylindrical fibers, utilizing a single elastomeric material and easily accessible chemicals. Different surface textures are attained through strain application or solvent-induced swelling, featuring well-defined wavelengths ranging from sub-microns to millimeters and offering easy adjustability. Such versatility renders these particles potentially invaluable for medical applications, especially in bacterial adhesion studies. The coexistence of "young" regions (smooth, with a small surface area) and "old" regions (wrinkled, with a large surface area) within the same material opens up avenues for biomimetic materials endowed with additional functionalities; for example, a Janus micromanipulator where micro- or nano-sized objects are grasped and transported by an array of wrinkled particles, facilitating precise release at designated locations through wrinkle pattern adjustments. This article underscores the versatility and potential applications of Janus elastomeric particles while highlighting the intriguing prospects of biomimetic materials with controlled surface textures. Janus ; Polyurethane ; Materials science ; Elastomer ; Composite material ; Polymer science ; Surface (topology) ; Nanotechnology ; Mathematics Pickering emulsions and particle stabilization ; Advanced Polymer Synthesis and Characterization ; Polymer composites and self-healing
Authors: Giorgio Domenichini
Source: The Journal of Chemical Physics (article, 2024-03-25)
Field: Materials Science — Materials Chemistry

Extending the definition of atomic basis sets to atoms with fractional nuclear charge Alchemical transformations showed that perturbation theory can be applied also to changes in the atomic nuclear charges of a molecule. The alchemical path that connects two different chemical species involves the conceptualization of a non-physical system in which an atom possess a non-integer nuclear charge. A correct quantum mechanical treatment of these systems is limited by the fact that finite size atomic basis sets do not define exponents and contraction coefficients for fractional charge atoms. This paper proposes a solution to this problem and shows that a smooth interpolation of the atomic orbital coefficients and exponents across the periodic table is a convenient way to produce accurate alchemical predictions, even using small size basis sets. Effective nuclear charge ; Basis (linear algebra) ; Atom (system on chip) ; Atoms in molecules ; Charge (physics) ; Physics ; Quantum mechanics ; Mathematics ; Statistical physics ; Atomic physics ; Theoretical physics ; Molecule ; Computer science ; Ion ; Geometry Machine Learning in Materials Science ; Advanced Chemical Physics Studies ; Crystallography and molecular interactions
Authors: Tiago M. Souza | Lucas B. Pena | Juarez L. F. Da Silva | Breno R. L. Galvão
Source: Physical Chemistry Chemical Physics (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Data-driven stabilization of Ni<sub><i>m</i></sub>Pd<sub><i>n</i>–<i>m</i></sub> nanoalloys: a study using density functional theory and data mining approaches Green hydrogen, generated through the electrolysis of water, is a viable alternative to fossil fuels, although its adoption is hindered by the high costs associated with the catalysts. Among a wide variety of potential materials, binary nickel-palladium (NiPd) systems have garnered significant attention, particularly at the nanoscale, for their efficacious roles in catalyzing hydrogen and oxygen evolution reactions. However, our atom-level understanding of the descriptors that drive their energetic stability at the nanoscale remains largely incomplete. Here, we investigate by density functional theory calculations the descriptors that drives the stability of the Ni<sub><i>m</i></sub>Pd<sub><i>n</i>-<i>m</i></sub> clusters for different sizes (<i>n</i> = 13, 27, 41) and compositions. To achieve our goals, a large number of trial configurations were generated and selected using data mining algorithms (<i>k</i>-means, t-SNE) and genetic algorithms, while the most important physical-chemical descriptors were identified using Spearman correlation analysis. We have found that core-shell formation, with the smaller Ni atoms lying in the center of the particle, plays a major role in the stabilization of the nanoalloys, and this effect causes the alloys to assume a icosahedral-fragment configuration (as the unary nickel cluster) instead of a fcc fragment (as the unary palladium cluster). However, the core-shell formation in this alloy is unique in that Pd poor compositions exhibit scattered Pd atoms on the surface. As the palladium content increases, this gives rise to the complete Pd shell. This stabilization mechanism is quantitatively supported by the different correlations observed in the number of Ni-Ni and Pd-Pd bonds with energy, in which the latter tends to decrease alloy stability. Furthermore, a notable trend is the correlation between the coordination number of Ni atoms with alloy stabilization, while the coordination of Pd atoms shows an inverse correlation. Density functional theory ; Computer science ; Data mining ; Chemistry ; Computational chemistry Machine Learning in Materials Science ; nanoparticles nucleation surface interactions ; Electrocatalysts for Energy Conversion
Authors: Chitransh Dixit | Kanchan Lata Dixit | Chandra Kumar Dixit | Praveen Kumar Pandey | Shavej Ali Siddiqui
Source: International journal of modern achievement in science, engineering and technology. (article, 2024-12-22)
Field: Chemistry — Organic Chemistry

Exploring Nanomaterials for Enhanced Catalysis in Chemical Reactions The study Nanotechnology has emerged as a ground-breaking frontier in the field of catalysis, offering promising avenues for revolutionizing chemical reactions. This abstract provides a concise overview of recent developments in harnessing nanomaterials to enhance catalytic processes. Nanomaterials, with their unique size-dependent properties and high surface area-to-volume ratios, have exhibited remarkable catalytic efficiency, selectivity, and stability. This abstract highlight key aspects of the research conducted to harness these advantages, including the synthesis and characterization of various nanomaterials such as nanoparticles, nanowires, and Nano sheets. These materials are tailored to optimize their catalytic performance by precisely controlling their size, shape, and composition. The discussion the diverse range of catalytic applications that benefit from nanomaterials, including green energy production, environmental remediation, and pharmaceutical synthesis. The enhanced catalytic activities facilitated by nanomaterials have the potential to reduce reaction times, lower energy consumption, and minimize waste products, contributing to more sustainable and efficient chemical processes and touches upon the challenges and future prospects of nanomaterial-based catalysis, emphasizing the need for further research to fully understand the underlying mechanisms and potential environmental and safety concerns. Collaborative efforts among chemists, material scientists, and engineers are essential to unlock the full potential of nanomaterials in catalysis and pave the way for innovative solutions to complex global challenges. Nanomaterials ; Nanotechnology ; Catalysis ; Biochemical engineering ; Characterization (materials science) ; Materials science ; Chemistry ; Engineering Nanomaterials for catalytic reactions
Authors: Muzamir Isa | M. N. Afnan Uda | Mohd Irfan | U. Hashim | Subash C. B. Gopinath | Hafiza Shukor | MRM Huzaifah | Maimunah Mohd Ali | Naimah Ibrahim | Muaz Mohd Zaini Makhtar | Qi Hwa Ng | M. K. R. Hashim | Z.A. Arsat | N. A. Parmin | Iyana Ahmad Sofri | Mahfuz Affif Mohd Ruslan | Tijjani Adam
Source: International Journal of Nanoelectronics and Materials (IJNeaM) (article, 2024-06-12)
Field: Materials Science — Materials Chemistry

Arthropods-mediated Green Synthesis of Zinc Oxide Nanoparticles using Cellar Spider Extract: A Biocompatible Remediation for Environmental Approach This study presents an eco-friendly approach to synthesizing zinc oxide nanoparticles (ZnO NPs) using extracts from cellar spiders, addressing environmental and health concerns associated with conventional methods. The spider extract efficiently reduced zinc acetate dihydrate, and the synthesized ZnO NPs underwent comprehensive quantitative characterization, including size, shape, morphology, surface chemistry, thermal stability, and optical properties using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), zeta potential measurements, thermogravimetric analysis (TGA), and UV-vis spectroscopy. The nanoparticles exhibited intended characteristics, and their adsorption capability for methylene blue (MB) was quantitatively assessed using the Freundlich isotherm model and pseudo-second-order kinetic model, providing numerical insights into MB removal efficiency. The study demonstrates the potential of these green-synthesized ZnO NPs for applications in environmental remediation, wastewater treatment, and antibacterial therapies, contributing to both sustainable nanomaterial development and quantitative understanding of their functional properties. Thermogravimetric analysis ; Zinc ; Nanomaterials ; Nanoparticle ; Fourier transform infrared spectroscopy ; Zeta potential ; Freundlich equation ; Chemical engineering ; Materials science ; Green chemistry ; Nuclear chemistry ; Environmental remediation ; Thermal stability ; Adsorption ; Chemistry ; Nanotechnology ; Organic chemistry ; Contamination Nanoparticles: synthesis and applications ; Laser-Ablation Synthesis of Nanoparticles ; Magnesium Oxide Properties and Applications
Authors: Isabel Desgagné‐Penix | Basanta Lamichhane | Sarah‐Eve Gélinas | Natacha Mérindol | Manoj Koirala | Karen Cristine Gonçalves dos Santos | Hugo Germain
Source: Research Square (preprint, 2024-09-09)
Field: Chemistry — Organic Chemistry

Elucidating the enzyme network driving Amaryllidaceae Alkaloids Biosynthesis Lycorine ; Biosynthesis ; Enzyme ; Nicotiana benthamiana ; Biochemistry ; Amaryllidaceae Alkaloids ; O-methyltransferase ; Chemistry ; Alkaloid ; Biology ; Stereochemistry ; Methyltransferase ; Methylation ; Gene Chemical synthesis and alkaloids ; Psychedelics and Drug Studies ; Alkaloids: synthesis and pharmacology
Authors: Е. Н. Муратова | A. A. Ponomareva | A. A. Shemukhin | Yuriy V. Balakshin | Aleksandr Evseev | В. А. Мошников | Anton Zhilenkov | Olga Yu. Kichigina
Source: Metals (article, 2024-05-30)
Field: Materials Science — Materials Chemistry

The Influence of the Structural Parameters of Nanoporous Alumina Matrices on Optical Properties In this work, two types of nanoporous alumina membranes were prepared and tested. Structural features of the samples obtained by using different acids were investigated by scanning electron microscopy (SEM). And further SEM-images were analyzed by different types of fractal dimension estimation methods. The transmission and scattering of accelerated He+ ions were studied in experiments on the ion irradiation of dielectric channels based on porous alumina. An ion accelerator was used as a source of the He+ beam with an energy of 1.7 MeV. Ion scattering was studied by Rutherford backscattering spectrometry. Helium transition through nanoporous alumina at various angles between the normal to the sample and the beam direction were observed. It is shown that the porous structure of anodic aluminum oxide is excellent as a dielectric matrix of nanocapillaries. Owing to the small angle scattering, it allows for the transportation of the accelerated charged particles through the dielectric capillaries, and, as a result, the localization of high energy ion irradiation effects. Additionally, according to the transmission of UV–V is spectra, the energy gaps of samples obtained were calculated. Nanoporous ; Materials science ; Scanning electron microscope ; Scattering ; Transmission electron microscopy ; Dielectric ; Rutherford backscattering spectrometry ; Ion ; Analytical Chemistry (journal) ; Irradiation ; Ion beam ; Optics ; Composite material ; Chemistry ; Optoelectronics ; Nanotechnology ; Thin film Anodic Oxide Films and Nanostructures ; Nanopore and Nanochannel Transport Studies ; Semiconductor materials and devices