jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Nicholas Ballard | Nerea Jiménez | José M. Asua
Source: Particle & Particle Systems Characterization (article, 2024-09-10)
Field: Materials Science — Polymers and Plastics

Physical Crosslinking of Aqueous Polymer Dispersions: A Perspective Abstract Colloidal polymers, and in particular aqueous polymer dispersions, are widely used in commercial applications such as coatings and adhesives. Historically, the solvent resistance and mechanical properties of these systems have been improved by covalently crosslinking the polymer chains after drying. More recently, work has been directed toward replacing this covalent crosslinking, which typically involves highly reactive functional groups, by physical crosslinking through the use of supramolecular interactions. While conceptually similar to the use of covalent crosslinking, physical crosslinking has a unique influence on the rheology of the polymer, which leads to substantial differences in the development of mechanical strength during drying, as well as the mechanical properties of the final polymer film. In this perspective, the advantages and challenges of this approach are outlined, and an outlook for future research in this direction is provided. Aqueous solution ; Polymer ; Perspective (graphical) ; Chemical engineering ; Polymer science ; Materials science ; Polymer chemistry ; Chemistry ; Organic chemistry ; Composite material ; Computer science Polymer composites and self-healing ; Advanced Polymer Synthesis and Characterization ; Supramolecular Self-Assembly in Materials
Authors: Hachem Araji | Maria Nakhoul | Elio J. Challita | Nour Barmo | Brigitte Wex
Source: Physical Chemistry Chemical Physics (article, 2024-01-01)
Field: Chemistry — Organic Chemistry

Cross-over from pyrene to acene optical and electronic properties: a theoretical investigation of a series of pyrene derivatives fused with N-, S, and O-containing heterocycles Pyrene and acene derivatives are an important source of materials for optoelectronic device applications both as emitters and organic semiconductors. The mobility of major charge carriers is correlated with the coupling constants of the respective major charge carrier as well as the relaxation energies. Herein, we have applied range-separated density functionals for the estimation of said values. A series of five alkylated derivatives of pyrene laterally extended by heteroaromatic or phenyl groups were explored and contrasted to nascent pyrene, alkylated pyrene and tetracene. The ground state geometries along with absorption properties and relaxation energies are presented as well as a discussion of the suitability of the material toward hole and electron transport materials. Pyrene ; Tetracene ; Acene ; Alkylation ; Chemistry ; Photochemistry ; Computational chemistry ; Organic chemistry ; Anthracene ; Molecule Synthesis and Properties of Aromatic Compounds ; Photochemistry and Electron Transfer Studies ; Nonlinear Optical Materials Research
Authors: Yunhui Wu | Cong Luo | Huanyu Liu | Wen Li | Jun‐Wei Zha
Source: eXPRESS Polymer Letters (article, 2024-01-01)
Field: Chemistry — Inorganic Chemistry

Fabricating multifunctional PLA textiles with advanced respiratory detection and environmental safety Currently, polylactic acid (PLA) is an attractive alternative to polypropylene (PP) because of its biodegradability.This study introduces a novel modification strategy for PLA by creating a multifunctional ionization layer with ionic salts.This approach achieves humidity sensing, reliable antibacterial properties, and excellent degradability simultaneously.The modified PLA textile sensor exhibits high sensitivity to respiratory humidity (0.92 at 90% RH), with ultrafast response (0.12 s) and recovery times (0.16 s).Additionally, the textile demonstrates excellent antibacterial performance against both E. coli (99.9%) and S. aureus (99.9%) after 1 h of contact.It also shows notable biodegradability with a weight loss rate of 60.38% after 30 days.Also, the ionic salt mechanism is explained through dynamic ionization interactions attributed to the modified ionic salts, which feature both long-chain alkanes and active ions.This work presents a new method to enhance the respiratory detection and antibacterial performance of biodegradable masks. Materials science ; Environmental safety ; Nanotechnology ; Polymer science ; Medicine ; Environmental health ; Human health Pigment Synthesis and Properties ; biodegradable polymer synthesis and properties ; Microplastics and Plastic Pollution
Authors: Heguang Sun | Lin Zhou | Meiyan Shu | Jie Zhang | Ziheng Feng | Haikuan Feng | Xiaoyu Song | Jibo Yue | Wei Guo
Source: Agriculture (article, 2024-03-15)
Field: Chemistry — Analytical Chemistry

Estimation of Peanut Southern Blight Severity in Hyperspectral Data Using the Synthetic Minority Oversampling Technique and Fractional-Order Differentiation Southern blight significantly impacts peanut yield, and its severity is exacerbated by high-temperature and high-humidity conditions. The mycelium attached to the plant’s interior quickly proliferates, contributing to the challenges of early detection and data acquisition. In recent years, the integration of machine learning and remote sensing data has become a common approach for disease monitoring. However, the poor quality and imbalance of data samples can significantly impact the performance of machine learning algorithms. This study employed the Synthetic Minority Oversampling Technique (SMOTE) algorithm to generate samples with varying severity levels. Additionally, it utilized Fractional-Order Differentiation (FOD) to enhance spectral information. The validation and testing of the 1D-CNN, SVM, and KNN models were conducted using experimental data from two different locations. In conclusion, our results indicate that the SMOTE-FOD-1D-CNN model enhances the ability to monitor the severity of peanut white mold disease (validation OA = 88.81%, Kappa = 0.85; testing OA = 82.76%, Kappa = 0.75). Oversampling ; Hyperspectral imaging ; Blight ; Order (exchange) ; Estimation ; Mathematics ; Statistics ; Environmental science ; Computer science ; Botany ; Biology ; Artificial intelligence ; Engineering ; Economics ; Telecommunications Spectroscopy and Chemometric Analyses ; Remote-Sensing Image Classification ; Remote Sensing and Land Use
Authors: Thomas Berkemeier | Ulrich Pöschl
Source: Angewandte Chemie International Edition (article, 2024-10-24)
Field: Materials Science — Materials Chemistry

Carbon Nanoparticle Oxidation by NO<sub>2</sub> and O<sub>2</sub>: Chemical Kinetics and Reaction Pathways Carbon nanoparticle interactions with gases are central to many environmental and technical processes, but the underlying reaction kinetics and mechanisms are not well understood. Here, we investigate the oxidation and gasification of carbon nanoparticles by NO<sub>2</sub> and O<sub>2</sub> under combustion exhaust conditions. We build on a comprehensive experimental data set and use a kinetic multilayer model (KM-GAP-CARBON) to trace the uptake and release of gas molecules alongside the temporal evolution of particle size and surface composition. The experimental results are captured by a model mechanism that involves different types of carbon atoms (edge/plane-like) and the formation of a reactive oxygen intermediate (activated CO complex) as the rate-limiting step. A transition between distinct chemical regimes driven by NO<sub>2</sub> at lower temperatures and O<sub>2</sub> at higher temperatures is reflected by an increase in the observable activation energy from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:semantics><mml:mo>∼</mml:mo> <mml:annotation>${ \sim }$</mml:annotation> </mml:semantics> </mml:math> 60 kJ/mol to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:semantics><mml:mo>∼</mml:mo> <mml:annotation>${ \sim }$</mml:annotation> </mml:semantics> </mml:math> 130 kJ/mol. We derive energy profiles for three alternative reaction pathways that involve uni- or bimolecular decomposition of reactive oxygen intermediates. Kinetics ; Carbon fibers ; Chemical kinetics ; Chemistry ; Oxygen ; Reaction mechanism ; Combustion ; Nanoparticle ; Activation energy ; Chemical reaction ; Decomposition ; Chemical engineering ; Chemical physics ; Materials science ; Nanotechnology ; Physical chemistry ; Catalysis ; Organic chemistry Catalytic Processes in Materials Science ; Thermochemical Biomass Conversion Processes ; Atmospheric chemistry and aerosols
Authors: Chadha Mejri | Walid Oueslati
Source: Earth Sciences (review, 2024-12-11)
Field: Materials Science — Biomaterials

A Critical Review of Clay Minerals for Groundwater Protection and Treatment Beneath the Earth’s surface lies a hidden realm of immense environmental and ecological significance—groundwater. This vital resource is faced with increasing threats from a myriad of contaminants, both natural and anthropogenic. Clay minerals, often overlooked components of geological formations, serve as nature’s heroes in protecting and remediating groundwater. This chapter highlights the remarkable role of clay minerals, particularly montmorillonite, in safeguarding groundwater. Their unique physico-chemical properties enable them to function as natural filters, adsorbents, and barriers against pollutants, with exceptional efficiency in ammonium removal through interlayer sites and cation exchange mechanisms. The chapter details how clay minerals manage harmful substances, preventing their spread into aquifers, and examines engineered clay solutions in groundwater remediation, emphasizing advancements in nanotechnology and material science. The chapter also addresses the challenges and limitations of clay minerals in different geological contexts and contamination scenarios, providing a balanced perspective on their role in groundwater protection. By shedding light on these ‘unsung heroes’, we aim to foster a deeper appreciation for the intricate natural systems that help maintain groundwater quality and inspire innovative approaches to water resource management and environmental remediation. Groundwater ; Environmental remediation ; Natural (archaeology) ; Aquifer ; Clay minerals ; Safeguarding ; Environmental science ; Groundwater remediation ; Earth science ; Environmental engineering ; Geology ; Contamination ; Geochemistry ; Ecology ; Geotechnical engineering Clay minerals and soil interactions ; Therapeutic Uses of Natural Elements ; Groundwater and Isotope Geochemistry
Authors: Wonjun Shin | Dong Hyun Lee | Raksan Ko | Ryun‐Han Koo | Hocheon Yoo | Sung‐Tae Lee
Source: Discover Nano (article, 2024-11-19)
Field: Materials Science — Materials Chemistry

Low-frequency noise of MoTe2 transistor: effects on ambipolar carrier transport and CYTOP doping Low-frequency noise (LFN) characteristics of semiconductor devices pose a significant importance for understanding their working principle, particularly concerning material imperfections. Accordingly, substantial research endeavors have focused on characterizing the LFN of devices. However, the LFN characteristics of the ambipolar transistors have been rarely demonstrated. Herein, we investigate the effects of ambipolar carrier transport and CYTOP-induced p-type doping on low-frequency noise characteristics of MoTe<sub>2</sub> transistors. The source of the 1/f noise differs between the n-type (electron transport) and p-type (hole transport) modes. Notably, the influence of contact resistance is more pronounced in the n-type mode. CYTOP doping suppresses the n-type mode by introducing hole doping effects. Furthermore, CYTOP doping mitigates the impact of contact resistance on excess noise. Ambipolar diffusion ; Doping ; Noise (video) ; Materials science ; Infrasound ; Optoelectronics ; Transistor ; Low frequency ; Semiconductor ; Electron ; Electrical engineering ; Physics ; Acoustics ; Computer science ; Engineering ; Telecommunications 2D Materials and Applications ; Semiconductor materials and devices ; Ferroelectric and Negative Capacitance Devices
Authors: B H Shivayogi | T. Manjunatha | Maruthi Prashanth B H | Sandeepkumar Gowda | Asif Iqbal Mulla | Divijesh Puninchathaya P
Source: Engineering Research Express (article, 2024-12-01)
Field: Materials Science — Polymers and Plastics

Assessment of fiber loading effects on mechanical properties and prediction of mechanical properties via artificial neural networks of hybrid jute /sheep wool epoxy composites Abstract The primary purpose of this study is to realize the effect of fibre loading on mechanical properties like tensile, bending, impact, interlaminar shear strength and fracture toughness of hybrid composites made of alkaline treated jute and sheep wool hybrid fibres and epoxy. A series of composite laminates were prepared with varying fibre (30%, 40%, 50% and 60%) loadings using hand layup technique. The findings indicated that hybrid composite with equal amount of fiber and resin (JW50) showed a higher strength of 40 MPa against tensile load, maximum strength of 99 MPa against bending load, superior interlaminar shear strength (ILSS) of 3.09 MPa, and a maximum fracture toughness of 72 MPa.m 1/2 compared to other fibre loadings. In terms of impact test, JW50 displayed the highest impact strength of 85.98 J/m, underscoring its exceptional capacity to absorb energy compared to other composites. The mechanical strengths of these composites were also predicted using an Artificial Neural Network (ANN) model, which generated accuracy of 87.46% for tensile strength, 86.31% for flexural strength, and 83.52% for impact strength. The absolute percentage errors were found to be 12.53%, 13.68%, and 16.47%, respectively, demonstrating the model’s reliability in estimating composite properties based on fibre content and composition. SEM images of fractured samples under tensile load reveal that higher resin content reduces fibre-matrix bonding, while a balanced fibre-to-resin ratio improves load transfer, but too much fibre leads to debonding due to inadequate resin justifying the experimental results. Epoxy ; Composite material ; Materials science ; Wool ; Fiber ; Natural fiber ; Artificial neural network ; Computer science ; Machine learning Textile materials and evaluations ; Natural Fiber Reinforced Composites ; Mechanical Engineering and Vibrations Research
Authors: Christopher M. Sims | Jeffrey Fagan
Source: The Journal of Physical Chemistry C (article, 2024-07-31)
Field: Materials Science — Materials Chemistry

Orthogonal Determination of Competing Surfactant Adsorption onto Single-Wall Carbon Nanotubes During Aqueous Two-Polymer Phase Extraction via Fluorescence Spectroscopy and Analytical Ultracentrifugation A combination of analytical ultracentrifugation (AUC) and fluorescence spectroscopy are utilized to orthogonally probe compositions of adsorbed surfactant layers on the surface of (7,5) species single-wall carbon nanotubes (SWCNTs) under conditions known to achieve differential partitioning in aqueous two-phase extraction (ATPE) separations. Fluorescence emission intensity and AUC anhydrous particle density measurements independently probe and can discriminate between adsorbed surfactant layers on a (7,5) nanotube comprised of either of two common nanotube dispersants, the anionic surfactants sodium deoxycholate and sodium dodecyl sulfate. Measurements on dispersions containing mixtures of both surfactants indicate near total direct exchange of the dominant surfactant species adsorbed to the carbon nanotube at a critical concentration ratio consistent with the ratio leading to partitioning change in the ATPE separation. By conducting these orthogonal measurements in a complex environment reflective of an ATPE separation, including multiple surfactant and polymer solution components, the results provide direct evidence for the hypothesis that it is the nature of the adsorbed surfactant layer that primarily controls partitioning behavior in selective ATPE separations of SWCNTs. Pulmonary surfactant ; Carbon nanotube ; Adsorption ; Sodium dodecyl sulfate ; Aqueous solution ; Chemistry ; Chemical engineering ; Fluorescence spectroscopy ; Polymer ; Dispersant ; Phase (matter) ; Aqueous two-phase system ; Extraction (chemistry) ; Chromatography ; Analytical Chemistry (journal) ; Fluorescence ; Organic chemistry ; Dispersion (optics) Carbon Nanotubes in Composites ; Nanopore and Nanochannel Transport Studies ; Electrochemical Analysis and Applications
Authors: Nils van Staalduinen | Christoph Bannwarth
Source: ChemRxiv (preprint, 2024-06-30)
Field: Chemistry — Spectroscopy

MolBar: A Molecular Identifier for Inorganic and Organic Molecules with Full Support of Stereoisomerism Before a new molecular structure is registered to a chemical structure database, a duplicate check is essential to ensure the integrity of the database. The Simplified Molecular Input Line Entry Specification (SMILES) and the IUPAC International Chemical Identifier (InChI) stand out as widely used molecular identifiers for these checks. Notable limitations arise when dealing with molecules from inorganic chemistry or structures characterized by non-central stereochemistry. When the stereoinformation needs to be assigned to a group of atoms, widely used identifiers cannot describe axial and planar chirality due to the atom-centered description of a molecule. To address this limitation, we introduce a novel chemical identifier called the Molecular Barcode (MolBar). Motivated by the field of theoretical chemistry, a fragment-based approach is used in addition to the conventional atomistic description. In this approach, the 3D structure of fragments are normalized using a specialized force field and characterized by physically inspired matrices derived solely from atomic positions. The resulting permutation-invariant representation is constructed from the eigenvalue spectra, providing comprehensive information on both bonding and stereochemistry. The robustness of MolBar is demonstrated through duplication and permutation invariance tests on the Molecule3D dataset of 3.9 million molecules. A Python implementation is available as open source and can be installed via pip install molbar. Identifier ; Organic molecules ; Molecule ; Chemistry ; Stereoisomerism ; Combinatorial chemistry ; Computational biology ; Computer science ; Organic chemistry ; Biology ; Programming language Analytical Chemistry and Chromatography ; Various Chemistry Research Topics ; Molecular spectroscopy and chirality
Authors: Dthenifer Cordeiro Santana | Rafael Felippe Ratke | F. L. Zanatta | Cid Naudi Silva Campos | Ana Carina da Silva Cândido Seron | Larissa Pereira Ribeiro Teodoro | Natielly Pereira da Silva | Gabriela Souza Oliveira | Regimar Garcia dos Santos | Rita de Cássia Félix Alvarez | Carlos Antônio da Silva | Matildes Blanco | Paulo Eduardo Teodoro
Source: AgriEngineering (article, 2024-11-26)
Field: Chemistry — Analytical Chemistry

Caffeine Content Prediction in Coffee Beans Using Hyperspectral Reflectance and Machine Learning The application of hyperspectral data in machine learning models can contribute to the rapid and accurate determination of caffeine content in coffee beans. This study aimed to identify the machine learning algorithm with the best performance for predicting caffeine content and to find input data for these models that can improve the accuracy of these algorithms. The coffee beans were harvested one year after the seedlings were planted. The fresh beans were taken to the spectroscopy laboratory (Laspec) at the Federal University of Mato Grosso do Sul, Chapadão do Sul campus, for spectral evaluation using a spectroradiometer. For the analysis, the dried coffee beans were ground and sieved for the quantification of caffeine, which was carried out using a liquid chromatograph on the Waters Acquity 1100 series UPLC system, with an automatic sample injector. The spectral data of the beans, as well as the spectral data of the roasted and ground coffee, were analyzed using machine learning (ML) algorithms to predict caffeine content. Four databases were used as input: the spectral information of the bean (CG), the spectral information of the bean with additional clone information (CG+C), the spectral information of the bean after roasting and grinding (CGRG) and the spectral information of the bean after roasting and grinding with additional clone information (CGRG+C). The caffeine content was used as an output to be predicted. Each database was subjected to different machine learning models: artificial neural networks (ANNs), decision tree (DT), linear regression (LR), M5P, and random forest (RF) algorithms. Pearson’s correlation coefficient, mean absolute error, and root mean square error were tested as model accuracy metrics. The support vector machine algorithm showed the best accuracy in predicting caffeine content when using hyperspectral data from roasted and ground coffee beans. This performance was significantly improved when clone information was included, allowing for an even more accurate analysis. Hyperspectral imaging ; Caffeine ; Reflectivity ; Content (measure theory) ; Remote sensing ; Artificial intelligence ; Environmental science ; Computer science ; Mathematics ; Geography ; Biology ; Optics ; Physics Spectroscopy and Chemometric Analyses
Authors: Ingrid Hagarová | Vasiľ Andruch
Source: Toxics (review, 2024-10-26)
Field: Materials Science — Materials Chemistry

Enhancing Analytical Potential for Ultratrace Analysis of Inorganic Oxyanions Using Extraction Procedures with Layered Double Hydroxides This article provides an overview of the use of layered double hydroxides (LDHs) as effective sorbents in various extraction methods, including column-based solid-phase extraction (SPE), dispersive solid-phase extraction (DSPE), and magnetic solid-phase extraction (MSPE), for the separation and preconcentration of inorganic oxyanions of chromium, arsenic, and selenium. The primary focus is on enhancing the analytical performance of spectrometric detection techniques, particularly in terms of sensitivity and selectivity when analyzing low concentrations of target analytes in complex matrices. LDHs, which can be readily prepared and structurally modified with various substances, offer promising potential for the development of novel analytical methods. When used in analytical extraction procedures and following careful optimization of experimental conditions, the developed methods have yielded satisfactory results, as documented by studies reviewed in this paper. This review is intended to assist analytical chemists in scientific laboratories involved in developing new extraction procedures. Layered double hydroxides ; Solid phase extraction ; Extraction (chemistry) ; Analyte ; Chemistry ; Inorganic arsenic ; Analytical procedures ; Complex matrix ; Arsenic ; Chromatography ; Inorganic chemistry Layered Double Hydroxides Synthesis and Applications ; Arsenic contamination and mitigation ; Lanthanide and Transition Metal Complexes