jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Mohammed Awad | Thomas A. Duever | Ramdhane Dhib
Source:  (preprint, 2023-07-19)
Field: Chemistry — Organic Chemistry

Experimental Investigation of Methyl Methacrylate in Stirred Batch Emulsion Reactor: AGET ATRP Approach &lt;p&gt;This study examines the ab initio emulsion atom transfer radical polymerization (ATRP) initiated by an eco-friendly reducing agent to produce poly(methyl methacrylate) (PMMA) polymer with controlled characteristics in a 2 L stirred batch reactor. The effect of the reaction temperature, surfactant concentration, monomer to water ratio, and stirring speed was thoroughly investigated. The results showed that PMMA coagulation becomes quite severe at a certain temperature threshold. However, the coagulation could be avoided at mild reaction temperature, since the outcomes showed that loading more surfactant to the system under high mixing speed has balanced the polymer mixture and yielded high monomer conversion. The PMMA product was analyzed by gravimetry and GPC measurements and after 5 h of polymerization at a reaction temperature of 50 degrees C, monomer conversion of 64.1% was obtained, and PMMA polymer samples produced had an average molar mass of 4.5 kg/mol and a polydispersity index of 1.17. The structure of the PMMA polymer was successfully proved by FTIR and nuclear magnetic resonance (NMR) spectroscopy. The results confirm the living feature of MMA AGET ATRP in emulsion medium and recommend further investigation for other types of surfactant.&lt;/p&gt; &lt;p&gt; &lt;/p&gt; Methyl methacrylate ; Dispersity ; Monomer ; Emulsion polymerization ; Polymer ; Materials science ; Polymer chemistry ; Polymerization ; Atom-transfer radical-polymerization ; Chemical engineering ; Molar mass ; Composite material Advanced Polymer Synthesis and Characterization
Authors: N. Kamalashri | B. V. Nagesh | K. N. Prathibha | R. Hari Krishna
Source: Journal of Mines Metals and Fuels (article, 2023-12-20)
Field: Materials Science — Materials Chemistry

Luminescence Spectroscopic Investigation of Eu&lt;sup&gt;3+&lt;/sup&gt; Doped Oxides: Review Given their potential utility in a variety of fields, including solid-state lighting, flat-panel displays, solar energy converters, optical amplifiers, and more, phosphors and glasses driven by Rare Earth (RE) ions and emitting multiple colors have attracted a lot of interest. Full-spectrum lighting, high-efficiency near-infrared emission, and wide colour gamut display are the primary difficulties for these emerging RE doped phosphors, which are dependent on the emission characteristics of the phosphors utilized. The various methods of synthesis for Eu3+ activated red emitting phosphors are discussed, with an emphasis on the aspects that contribute to improved luminous performance. This luminescence analysis is used in investing the Crystal structure and defects in metal oxides from which it provides information on the chemical and mechanical behavior of metal oxides during mining and processing operations. In this description, we outline the research findings and talk about the luminescence theory of the Eu3+ doped glasses and oxides for the red emission. Luminescence ; Doping ; Materials science ; Persistent luminescence ; Chemistry ; Optoelectronics ; Thermoluminescence Luminescence Properties of Advanced Materials ; Catalytic Processes in Materials Science ; Nuclear materials and radiation effects
Authors: Amira Bencherif | Monique Tie | Richard Martel | Delphine Bouilly
Source: ChemRxiv (preprint, 2023-11-15)
Field: Materials Science — Materials Chemistry

Automated and Parallel Transfer of Arrays of Oriented Graphene Ribbons The transfer of two-dimensional materials from their growth substrate onto application wafers is a critical bottleneck in scaling-up devices based on such nanomaterials. Here, we present an innovative approach to achieve the automated and simultaneous transfer of arrays of graphene ribbons, with precise control over their orientation and alignment onto patterned wafers. The transfer is executed in a simple, yet efficient apparatus consisting of an array of glass columns, strategically shaped to control ribbon orientation and arranged to match the destination wafer, coupled to a dual inflow/outflow pumping system. This apparatus enables the transfer of a custom array of parallel graphene ribbons in a fraction of the time required with traditional methods. The quality of the transferred graphene was evaluated using optical imaging, scanning electron microscopy, hyperspectral Raman imaging, and electrical transport: all consistently indicating that the transferred graphene exhibits excellent quality, comparable to a manual transfer by an expert user. The proposed apparatus offers several competitive advantages, including ease of use, high transfer throughput, and reduced nanomaterial consumption. Moreover, it can be used repeatedly on the same wafer to assemble arrays of overlayed materials with controlled relative orientations. This approach thus opens promising opportunities for the large scale fabrication of various heterostructures and devices based on vertical assemblies of 2D nanomaterials. Wafer ; Graphene ; Materials science ; Nanotechnology ; Nanomaterials ; Substrate (aquarium) ; Optoelectronics Graphene research and applications ; Advanced Memory and Neural Computing ; Quantum and electron transport phenomena
Authors: Djordje Došenović | Kanishka Sharma | Samuel Dechamps | Jean‐Luc Rouvière | Ying‐Bo Lu | A. Mordant | M. den Hertog | Luigi Genovese | Simon M.‐M. Dubois | Jean‐Christophe Charlier | Matthieu Jamet | A. Marty | Hanako Okuno
Source: arXiv (Cornell University) (preprint, 2023-10-13)
Field: Materials Science — Materials Chemistry

Atomic scale imaging of the negative charge induced by a single vanadium dopant atom in monolayer WSe$_2$ using 4D-STEM There has been extensive activity exploring the doping of semiconducting two-dimensional (2D) transition metal dichalcogenides in order to tune their electronic and magnetic properties. The outcome of doping depends on various factors, including the intrinsic properties of the host material, the nature of the dopants used, their spatial distribution as well as their interactions with other types of defects. A thorough atomic-level analysis is essential to fully understand these mechanisms. In this work, vanadium doped WSe$_2$ monolayer grown by molecular beam epitaxy is investigated using four-dimensional scanning transmission electron microscopy (4D-STEM). Through center of mass-based reconstruction, atomic scale maps are produced, allowing the visualization of both the electric field and the electrostatic potential around individual V atoms. To provide quantitative insights, these results are successfully compared with multislice image simulations based on ab initio calculations, accounting for lens aberrations. Finally, a negative charge around the V dopants is detected as a drop in the electrostatic potential, unambiguously demonstrating that 4D-STEM can be used to detect and to accurately analyze single dopant charge states in semiconducting 2D materials. Dopant ; Scanning transmission electron microscopy ; Materials science ; Doping ; Atomic units ; Vanadium ; Monolayer ; Kelvin probe force microscope ; Atom (system on chip) ; Condensed matter physics ; Chemical physics ; Nanotechnology ; Optoelectronics ; Chemistry ; Transmission electron microscopy ; Physics 2D Materials and Applications ; Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films
Authors: László Hegedűs | Zoltán Hell
Source: Periodica Polytechnica Chemical Engineering (article, 2023-09-21)
Field: Chemistry — Organic Chemistry

Applying Heterogeneous Catalytic Reactions for Organic Chemical Syntheses In this review the most important results achieved in the recent 12–15 years are summarized focusing on the heterogenous catalytic hydrogenations over transition metals (Pd, Pt, Ru, Rh, La), as well as the application of palladium, copper and other metals on a molecular sieve (4A) support in several organic chemical syntheses in liquid phase. Catalysis ; Molecular sieve ; Palladium ; Transition metal ; Copper ; Chemistry ; Liquid phase ; Organic synthesis ; Fine chemical ; Organic chemistry ; Combinatorial chemistry ; Thermodynamics Nanomaterials for catalytic reactions ; Asymmetric Hydrogenation and Catalysis ; Catalysis for Biomass Conversion
Authors: Naba Abuhafez
Source: theses.fr (ABES) (article, 2023-12-01)
Field: Materials Science — Materials Chemistry

Chimie durable à partir des catalyseurs supramoléculaires L’étude des procédés durables concernant la catalyse avec des métaux de transition est importante pour le futur de notre société. Dans cette thèse, de nouveaux systèmes catalytiques à base de cobalt pour l’oxydation des oléfines en cétones, une réaction généralement réalisée avec du palladium, ont été développés. Le système fonctionne à pression et température ambiantes avec une activité et une sélectivité remarquables, dépassant même dans certains cas les catalyseurs au fer de pointe. Ce procédé catalysé par le cobalt est compatible avec l’utilisation de polyméthylhydrosiloxane, lequel est un déchet chimique de l’industrie du silicium et il était utilisé comme source d'hydrogène en présence d'oxygène pour la catalyse au cobalt. La réaction s’est déroulée via un cycle catalytique original. Afin de développer des catalyseurs comportant des sites de reconnaissance moléculaire dans la 2ème sphère de coordination, comme le font les enzymes, un catalyseur supramoléculaire au palladium comprenant une porphyrine de zinc pour la reconnaissance des substrats a été étudié en catalyse de type Heck. Des interactions faibles Zn...N entre le site de reconnaissance et les dérivés de la pyridine ont joué un rôle clé même à haute température pour améliorer l’activité du catalyseur au palladium. Des études de diffraction des rayons X ont permis d’évoquer l'éventuelle complexité associée au mode d’action de ces catalyseurs. Enfin, des complexes de ruthénium se sont révélés être d’excellents catalyseurs pour le couplage croisé oxydatif de dérivés vinyliques conduisant à des précurseurs du nylon après hydrogenation in situ. Catalysis ; Cobalt ; Transition metal ; Zinc Mesoporous Materials and Catalysis ; Catalysis and Hydrodesulfurization Studies ; Surface Chemistry and Catalysis
Authors: Bohan Hu | Zitong Bao | Rixing Jiang | Yuhan Zhang
Source: Applied and Computational Engineering (article, 2023-07-21)
Field: Chemistry — Spectroscopy

Introduction to organic synthetic method retrosynthetic analysis Retrosynthesis is a method that uses the target molecule, which is a product, to predict the reactant, which is useful in organic synthesis and also a reverse way of synthesis. This paper introduces retrosynthetic analysis of organic compounds and helps new learners to have a brief understanding of what retrosynthetic analysis is, the disconnection methods, guidelines and real world applications of retrosynthesis based on an easy and basic explanation. Understanding retrosynthesis is helpful in industrial uses and manufacturing, as it can figure out the most efficient strategy by comparing different synthetic routine. Retrosynthetic analysis ; Disconnection ; Engineering ; Computer science ; Artificial intelligence ; Chemistry Analytical Chemistry and Chromatography ; Various Chemistry Research Topics ; Chemical Synthesis and Analysis
Authors: Aparna Joshi | G. Gnanarajan
Source: Journal for ReAttach Therapy and Developmental Diversities (article, 2023-06-01)
Field: Materials Science — Materials Chemistry

Exploring Cocrystals: Preparation Tactics, Advantages, And Formation Mechanisms The low solubility profile of drugs is one of the most demanding characteristics in drug dosage development, restraining the bioavailability of any drug. Based on solubility and permeability profiles, drugs are categorized into four different groups by the biopharmaceutical Classification system (BCS), which provides guidance optimization of dosage form for any drug. Many formulation methods for solubility enhancement of drugs having low solubility have been prepare. While they have shown fruitful results in enhancing drug bioavailability effectively, outcomes of these methods are based on certain physicochemical conditions of that molecule. Some of these methods have been discussed in this article. The preferred drug formulation for the majority of APIs continues to be oral dosage forms. Pharmaceutical co-crystals are a cutting-edge approach for increasing the bioavailability of low-solubility drugs in oral dosage form by boosting solubility, micrometric properties, dissolution rate, and stability. Co-crystals are the combination of an active pharmaceutical ingredient and one or more pharmaceutically accepted guest molecules called coformer in a stoichiometric ratio in a crystal lattice. In the current scenario, the solubility profile of drugs is a leading concern in drug development in pharma industry. This review paper offers a thorough examination of pharmaceutical cocrystals, encompassing preparation techniques, physicochemical characteristics, and practical uses. It serves as a valuable resource for improving the design and production of pharmaceutical cocrystals with specific physicochemical traits and intended applications, providing valuable insights for their efficient development Nanotechnology ; Computer science ; Chemistry ; Biochemical engineering ; Materials science ; Engineering Crystallization and Solubility Studies ; nanoparticles nucleation surface interactions ; Calcium Carbonate Crystallization and Inhibition
Authors: Shoaib Nazir
Source: Modern Concepts in Material Science (article, 2023-12-11)
Field: Materials Science — Materials Chemistry

Nanotechnology and 2D MXenes: A Promising Synergy for Advanced Materials Nanotechnology, with its ability to manipulate matter at the atomic and molecular scale, has significantly influenced the development of advanced materials.This mini-review explores the synergistic relationship between nanotechnology and 2D MXenes, a family of two-dimensional transition metal carbides, nitrides, and carbonitrides.The review encompasses the synthesis methods of 2D MXenes, emphasizing the role of nanotechnology in achieving precise control over material properties.The structural characteristics of MXenes at the nanoscale are elucidated, showcasing their unique electronic properties and the tools, such as scanning tunneling microscopy and atomic force microscopy, that enable their detailed investigation.The integration of nanotechnology in the manipulation of electronic properties is discussed, emphasizing the tunable conductivity of MXenes and their potential applications in electronic devices.The energy storage applications of MXenes, particularly in supercapacitors and batteries, are highlighted, showcasing how nanoscale engineering enhances their electrochemical performance.The catalytic and sensing capabilities of MXenes, augmented by nanotechnology, are explored, underscoring their potential in diverse chemical and sensing platforms.The review extends into the realm of biomedical applications, where the combination of nanotechnology and MXenes opens new possibilities in drug delivery, imaging, and theranostics.The challenges in the field, including scalability of synthesis methods and long-term stability of nanocomposites, are addressed. MXenes ; Nanotechnology ; Materials science ; Engineering ethics ; Engineering MXene and MAX Phase Materials ; Graphene research and applications ; Advanced Memory and Neural Computing
Authors: Tianyi Xi
Source: Applied and Computational Engineering (article, 2023-07-17)
Field: Materials Science — Materials Chemistry

Current synthesis routine of Mxene and its applications 2D transition metal carbides or nitrides are called Mxene, which can be treated as a promising inorganic material which is made up of a few atomic layers of transition metal carbide or nitrides. The properties of Mxene can be determined by the surface groups and the number of layers in the films. The Mxene can be made by top-down strategies which involves HF etching, salt etching, and electrochemical etching. Also, the bottom-up approach is available by using the CVD method. Some typical uses from the wide range of applications of Mxene are included in the article, which include energy storage, gas sensing, and optoelectronic use. Etching (microfabrication) ; Nitride ; Materials science ; Carbide ; Nanotechnology ; Transition metal ; Electrochemistry ; Optoelectronics ; Metallurgy ; Chemistry ; Catalysis ; Layer (electronics) ; Electrode MXene and MAX Phase Materials ; Advanced Memory and Neural Computing ; Boron and Carbon Nanomaterials Research
Authors: Antonio Maggiore | Yangyang Qu | Piotr Pander | Fernando B. Dias | Gilles Clavier | Régis Guillot | Pierre Audebert | Fabien Miomandre
Source: ChemRxiv (preprint, 2023-04-05)
Field: Materials Science — Materials Chemistry

Sonocrystallization Induced Thermally Activated Delayed Fluorescence via Distortion of Molecular Geometry In this work we present three donor-acceptor thermally activated delayed fluorescence (TADF) molecules comprising a 2,3,5,6-tetrafluorobenzonitrile acceptor with various electron donor units: phenoxazine (Phx-BzN), phenothiazine (Pht-BzN), and carbazole (Cz-BzN). These molecules have been studied using steady-state and time-resolved photophysical techniques in solution, film and in crystal state. While Cz-BzN displays TADF in solution and PMMA films, Phx-BzN and Pht-BzN are non-emissive in solution and somewhat emissive in polymer films. More interestingly, while Pht-BzN remains virtually non-emissive in all studied solvents, it exhibits strong photoluminescence and TADF in crystal state, attributed to Crystallization Induced Emission (CIE). We demonstrate through computational studies that the CIE properties arise due to intermolecular interactions in the crystal structure that result in locking the ground state molecular geometry and blocking relaxation in the excited state. As a result, the oscillator strength in the crystal form is enhanced leading to a highly luminescent behaviour, while in solution it equals nearly zero due to the molecule adopting a perfectly orthogonal D-A orientation in the excited state. Excited state ; Intermolecular force ; Carbazole ; Acceptor ; Intersystem crossing ; Fluorescence ; Photoluminescence ; Molecule ; Phenoxazine ; Crystal (programming language) ; Materials science ; Photochemistry ; Relaxation (psychology) ; Chemistry ; Crystallography ; Phenothiazine ; Singlet state ; Optoelectronics ; Optics ; Atomic physics ; Physics ; Organic chemistry Luminescence and Fluorescent Materials ; Organic Light-Emitting Diodes Research ; Photochemistry and Electron Transfer Studies
Authors: T.E. Seisembekova | А.К. Aimukhanov | B.R. Ilyassov | Damir Valiev | A.K. Zeinidenov | A.M. Zhakhanova
Source: Bulletin of the Karaganda University Physics Series (article, 2023-06-30)
Field: Materials Science — Polymers and Plastics

Effect of ZnO in various alcohols on photoelectric characteristics of OSC The paper presents the results of a study of the effect of alcohols on the electron transport of the ETL layer of a ZnO polymer solar cell with an inverted structure. To obtain films, zinc acetate was dissolved under the same experimental conditions in isopropanol, butanol and ethanol. According to the SEM data, it was found that the use of various alcohol solvents in the synthesis of the film shows a change in the morphology of the surface. The observed changes in the interface of the surface of the films are associated with the formation of ZnO aggregates depending on the polarity used of the alcohols. It is shown that the optical width of the ZnO band gap also depends on alcohol solvents. It is shown that the aggregation of ZnO has an effect on the electron transport and efficiency of the polymer solar cell. The voltage characteristics of the solar cells FTO/ ZnO/P3HT: IC60MA/PEDOT: PSS/Ag were measured. It is shown that the smallest aggregation of ZnO is observed in Isopropanol, in which the organic cell showed the highest efficiency of converting solar energy into electrical energy. The polymer solar cell has been the efficiency 2.5 %. From the obtained ETL impedance measurement data, the ZnO based layer obtained in Ethanol has the lowest electron transport parameters. This is due to the high degree of aggregation of ZnO, as a result of which the resistance to increases of the interface ZnO/FTO. The solar cells based ZnO in Ethanol demonstrated an efficiency value of 0.9 % compared to ZnO in Butanol with an efficiency of 1.6 %. PEDOT:PSS ; Materials science ; Solar cell ; Band gap ; Chemical engineering ; Zinc ; Polymer ; Organic solar cell ; Butanol ; Polyvinyl alcohol ; Photoelectric effect ; Alcohol ; Ethanol ; Chemistry ; Optoelectronics ; Organic chemistry ; Composite material Conducting polymers and applications ; Organic Electronics and Photovoltaics ; Polymer Nanocomposite Synthesis and Irradiation
Authors: Oksana V. Nesterova | Svitlana R. Petrusenko | Brian W. Skelton | Dmytro S. Nesterov
Source: Molecules (article, 2023-11-18)
Field: Chemistry — Inorganic Chemistry

Halogen-Dependent Diversity and Weak Interactions in the Heterometallic Ni/Cd Complex Solids: Structural and Theoretical Investigation Three novel heterometallic Ni/Cd coordination compounds [Ni(en)<sub>3</sub>][CdCl<sub>4</sub>]∙3dmso (<b>1</b>), [Ni(en)<sub>2</sub>(dmf)<sub>2</sub>][CdBr<sub>4</sub>] (<b>2</b>), and [Ni(en)<sub>3</sub>]<sub>2</sub>[CdI<sub>4</sub>](I)<sub>2</sub> (<b>3</b>) have been synthesized through the self-assembly process in a one-pot reaction of cadmium oxide, nickel salt (or nickel powder), NH<sub>4</sub>X (X = Cl, Br, I), and ethylenediamine in non-aqueous solvents dmso (for <b>1</b>) or dmf (for <b>2</b> and <b>3</b>). Formation of the one- (<b>1</b>) or three-dimensional (<b>2</b> and <b>3</b>) hydrogen-bonded frameworks has been observed depending on the nature of the [CdX<sub>4</sub>]<sup>2-</sup> counter-anion, as well as on the nature of the solvent. The electronic structures of [Ni(en)<sub>3</sub>]<sup>2+</sup> and [Ni(en)<sub>2</sub>(dmf)<sub>2</sub>]<sup>2+</sup> cations were studied at the DFT and CASSCF levels, including the ab initio ligand field theory (AILFT) calculations. The non-covalent intermolecular contacts between the cationic nickel and anionic cadmium blocks in the solid state were investigated by the QTAIM analysis. The mechanism of ligand substitution at the nickel center in [Ni(en)<sub>2</sub>(dmf)<sub>2</sub>]<sup>2+</sup> was theoretically investigated at the ωB97X-D4/ma-def2-TZVP//DLPNO-CCSD(T)/ma-def2-TZVPP level. The results demonstrate that thermodynamic factors are structure-determining ones due to low energy barriers of the rotation of dmf ligands in [Ni(en)<sub>2</sub>(dmf)<sub>2</sub>]<sup>2+</sup> (below 3 kcal mol<sup>-1</sup>) and the reversible transformation of [Ni(en)<sub>2</sub>(dmf)<sub>2</sub>]<sup>2+</sup> into [Ni(en)<sub>3</sub>]<sup>2+</sup> (below 20 kcal mol<sup>-1</sup>). Nickel ; Chemistry ; Crystallography ; Intermolecular force ; Ligand (biochemistry) ; Ethylenediamine ; Hydrogen bond ; Halogen bond ; Solvent ; Halogen ; Ab initio ; Cationic polymerization ; Physical chemistry ; Inorganic chemistry ; Computational chemistry ; Molecule ; Polymer chemistry ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Organic and Molecular Conductors Research ; Crystallography and molecular interactions