jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Ana Puente-Santamaría | Francisco Ortega | Armando Maestro | Ramón G. Rubio | Eduardo Guzmán
Source: Current Opinion in Colloid & Interface Science (review, 2024-04-04)
Field: Chemistry — Organic Chemistry

Non-equilibrium states in polyelectrolyte-surfactant systems at fluid interfaces: A critical review Over the last two decades, a significant body of research has been developed trying to understand the association and properties of mixtures formed by oppositely charged polyelectrolytes and surfactants. Particular emphasis has been given to their interfacial properties and the intriguing formation of nonequilibrium states. The synergy between these components at interfaces has attracted considerable attention due to its relevance in various industrial and biological applications. The combination of oppositely charged entities leads to complex interactions that influence the stability and behavior of interfaces. This review critically examines recent advances toward understanding the interfacial behavior when polyelectrolytes and surfactants coexist. Emphasis is placed on the existence of nonequilibrium states, shedding light on transient phenomena and kinetic aspects that play a crucial role in the overall system behavior. This will provide insights into the mechanisms governing the interfacial phenomena in these mixed systems. In summary, this review will contribute to the fundamental understanding of colloidal and interfacial science, offering a valuable perspective on designing and optimizing materials with tailored properties. Polyelectrolyte ; Pulmonary surfactant ; Thermodynamics ; Materials science ; Chemistry ; Physics ; Polymer ; Organic chemistry Surfactants and Colloidal Systems ; Electrostatics and Colloid Interactions ; Polymer Surface Interaction Studies
Authors: Le‐Wei Miao | Peng Chen | Meng-Xue Hu | Jin Yin | Hongying Du | Yijun Jiang
Source: Advanced Synthesis & Catalysis (article, 2024-03-22)
Field: Chemistry — Organic Chemistry

Divergent Synthesis of <i>Di</i>‐ and <i>Mono</i>‐Alkylated Indoles <i>via</i> Tunable Iron‐Catalyzed Hydroarylation of Styrenes Abstract We report an iron‐catalyzed divergent synthesis of alkylated indoles based on precise control of the activation sites on indoles through the selection of catalysts. Using indoles and styrenes as starting materials, 3,5‐ di ‐alkylated indoles could be prepared selectively and directly for the first time by treating with a catalytic amount of Fe(OTf) 3 and 3‐alkylated indoles were achieved exclusively by adding a catalytic amount of γ ‐cyclodextrin as the cocatalyst with Fe(OTf) 3 . This simple method was demonstrated with 52 examples with high yields and broad functional group compatibilities. Alkylation ; Chemistry ; Catalysis ; Combinatorial chemistry ; Organic chemistry ; Reaction conditions Catalytic C–H Functionalization Methods ; Asymmetric Hydrogenation and Catalysis ; Synthesis and Catalytic Reactions
Authors: Zan Lamberger | Vivien Priebe | Matthias Ryma | Gregor Lang
Source: Small Methods (article, 2024-12-17)
Field: Materials Science — Biomaterials

A Versatile Method to Produce Monomodal Nano‐ to Micro‐Fiber Fragments as Fillers for Biofabrication A key goal of biofabrication is the production of 3D tissue models with biomimetic properties. In natural tissues, fibrils-mainly composed of collagen-play a critical role in stabilizing and spatially organizing the extracellular matrix. To use biomimetic fibers for reinforcing bioinks in 3D printing, fiber fragmentation is necessary to prevent nozzle clogging. However, existing fragmentation methods are often material-specific, poorly scalable, and provide limited control over fragment size and shape. A novel workflow is introduced for producing fiber fragments applicable to various materials and fabrication techniques such as electrospinning, melt-electrowriting, fused deposition modeling, wet spinning, and microfluidic spinning. The method uses a sacrificial membrane as a substrate for precise cryo-sectioning of fibers. A significant advantage is that no additional handling steps, such as fiber detachment or transfer, are needed, resulting in highly reproducible fiber sectioning with a quasi-monodisperse length distribution. The membrane can be rolled before cutting, preventing fibers from sticking together and significantly increasing production efficiency. This method is also versatile, applicable to multiple fiber types and materials without re-parameterization. Cell culture experiments demonstrate that the fibers maintain key properties necessary for cell-fiber interactions, making them suitable for systematic screenings in the development of anisotropic 3D tissue models. Biofabrication ; Materials science ; Electrospinning ; Nanotechnology ; Fiber ; Spinning ; Tissue engineering ; Microfluidics ; Polymer ; Composite material ; Biomedical engineering Electrospun Nanofibers in Biomedical Applications ; 3D Printing in Biomedical Research ; Tissue Engineering and Regenerative Medicine
Authors: Qingqing Ma | Xue‐Jing Zhai | Jia‐Hong Huang | Yubing Si | Xi‐Yan Dong | Shuang‐Quan Zang | Thomas C. W. Mak
Source: Nanoscale (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Construction of novel Ag(0)-containing silver nanoclusters by regulating auxiliary phosphine ligands Controlled synthesis of metal clusters through minor changes in surface ligands holds significant interest because the corresponding entities serve as ideal models for investigating the ligand environment's stereochemical and electronic contributions that impact the corresponding structures and properties of metal clusters. In this work, we obtained two Ag(0)-containing nanoclusters (Ag17 and Ag32) with near-infrared emissions by regulating phosphine auxiliary ligands. Ag17 and Ag32 bear similar shells wherein Ag17 features a trigonal bipyramid Ag<sub>5</sub> kernel while Ag32 has a bi-icosahedral interpenetrating an Ag<sub>20</sub> kernel. Ag17 and Ag32 showed a near-infrared emission (NIR) of around 830 nm. Benefiting from the rigid structure, Ag17 displayed a more intense near-infrared emission than Ag32. This work provides new insight into the construction of novel superatomic silver nanoclusters by regulating phosphine ligands. Nanoclusters ; Phosphine ; Materials science ; Nanotechnology ; Combinatorial chemistry ; Chemistry ; Organic chemistry ; Catalysis Nanocluster Synthesis and Applications ; Gold and Silver Nanoparticles Synthesis and Applications ; Random Matrices and Applications
Authors: Binghao Zhang | Pengye Guo | Xinye Sun | Yanzhe Shang | Yuanchan Luo | Hui Wu
Source: Bioresources and Bioprocessing (article, 2024-09-19)
Field: Materials Science — Biomaterials

Enhancement of lactate fraction in poly(lactate-co-3-hydroxybutyrate) biosynthesized by metabolically engineered E. coli Poly(lactate-co-3-hydroxybutyrate) [P(LA-co-3HB)] is a high-molecular-weight biomaterial with excellent biocompatibility and biodegradability. In this study, the properties of P(LA-co-3HB) were examined and found to be affected by its lactate fraction. The efficiency of lactyl-CoA biosynthesis from intracellular lactate significantly affected the microbial synthesis of P(LA-co-3HB). Two CoA transferases from Anaerotignum lactatifermentans and Bacillota bacterium were selected for use in copolymer biosynthesis from 11 candidates. We found that cot<sub>Al</sub> enhanced the lactate fraction by 31.56% compared to that of the frequently used modified form of propionyl-CoA transferase from Anaerotignum propionicum. In addition, utilizing xylose as a favorable carbon source and blocking the lactate degradation pathway further enhanced the lactate fraction to 30.42 mol% and 52.84 mol%, respectively. Furthermore, when a 5 L bioreactor was used for fermentation utilizing xylose as a carbon source, the engineered strain produced 60.60 wt% P(46.40 mol% LA-co-3HB), which was similar to the results of our flask experiments. Our results indicate that the application of new CoA transferases has great potential for the biosynthesis of other lactate-based copolymers. Biocompatibility ; Xylose ; Chemistry ; Biosynthesis ; Polyhydroxyalkanoates ; Fermentation ; Biochemistry ; Industrial and production engineering ; Bioreactor ; Biomaterial ; Biodegradation ; Nuclear chemistry ; Chromatography ; Bacteria ; Organic chemistry ; Enzyme ; Biology biodegradable polymer synthesis and properties ; Microbial Metabolic Engineering and Bioproduction ; Biofuel production and bioconversion
Authors: Mohd Ishtiyak | Spencer R. Watts | Bhushan Thipe | F. Womack | P. W. Adams | Xiaojian Bai | David P. Young | Svilen Bobev | Sviatoslav Baranets
Source: Inorganic Chemistry (article, 2024-06-21)
Field: Materials Science — Materials Chemistry

Advancing Heteroanionicity in Zintl Phases: Crystal Structures, Thermoelectric and Magnetic Properties of Two Quaternary Semiconducting Arsenide Oxides, Eu<sub>8</sub>Zn<sub>2</sub>As<sub>6</sub>O and Eu<sub>14</sub>Zn<sub>5</sub>As<sub>12</sub>O Two novel quaternary oxyarsenides, Eu<sub>8</sub>Zn<sub>2</sub>As<sub>6</sub>O and Eu<sub>14</sub>Zn<sub>5</sub>As<sub>12</sub>O, were synthesized through metal flux reactions, and their crystal structures were established by single-crystal X-ray diffraction methods. Eu<sub>8</sub>Zn<sub>2</sub>As<sub>6</sub>O crystallizes in the orthorhombic space group <i>Pbca</i>, featuring polyanionic ribbons composed of corner-shared triangular [ZnAs<sub>3</sub>] units, running along the [100] direction. The structure of Eu<sub>14</sub>Zn<sub>5</sub>As<sub>12</sub>O crystallizes in the monoclinic space group <i>P</i>2/<i>m</i> and its anionic substructure can be described as an infinite "ribbonlike" chain comprised of [ZnAs<sub>3</sub>] trigonal-planar units, although the structural complexity here is greater and also amplified by disorder on multiple crystallographic positions. In both structures, the O<sup>2-</sup> anion occupies an octahedral void with six neighboring Eu<sup>2+</sup> cations. Formal electron counting, electronic structure calculations, and transport properties reveal the charge-balanced semiconducting nature of these heteroanionic Zintl phases. High-temperature thermoelectric transport properties measurements on Eu<sub>14</sub>Zn<sub>5</sub>As<sub>12</sub>O reveal relatively high resistivity (<i>ρ</i><sub>500K</sub> = 8 Ω·cm) and Seebeck coefficient values (<i>S</i><sub>500K</sub> = 220 μV K<sup>-1</sup>), along with a low concentration and mobility of holes as the dominant charge-carriers (<i>n</i><sub>500K</sub> = 8.0 × 10<sup>17</sup> cm<sup>-3</sup>, <i>μ</i><sub>500K</sub> = 6.4 cm<sup>2</sup>/V s). Magnetic studies indicate the presence of divalent Eu<sup>2+</sup> species in Eu<sub>14</sub>Zn<sub>5</sub>As<sub>12</sub>O and complex magnetic ordering, with two transitions observed at <i>T</i><sub>1</sub> = 21.6 K and <i>T</i><sub>2</sub> = 9 K. Chemistry ; Crystallography ; Orthorhombic crystal system ; Zintl phase ; Crystal structure ; Seebeck coefficient ; Monoclinic crystal system ; Arsenide ; Thermoelectric effect ; Isostructural ; Condensed matter physics ; Gallium arsenide Advanced Thermoelectric Materials and Devices ; Iron-based superconductors research ; Rare-earth and actinide compounds
Authors: Areti Zindrou | Pavlos Psathas | Yiannis Deligiannakis
Source: Nanomaterials (article, 2024-02-11)
Field: Materials Science — Materials Chemistry

Flame Spray Pyrolysis Synthesis of Vo-Rich Nano-SrTiO3-x Engineering of oxygen vacancies (Vo) in nanomaterials allows diligent control of their physicochemical properties. SrTiO<sub>3</sub> possesses the typical ABO<sub>3</sub> structure and has attracted considerable attention among the titanates due to its chemical stability and its high conduction band energy. This has resulted in its extensive use in photocatalytic energy-related processes, among others. Herein, we introduce the use of Flame Spray Pyrolysis (FSP); an industrial and scalable process to produce Vo-rich SrTiO<sub>3</sub> perovskites. We present two types of Anoxic Flame Spray Pyrolysis (A-FSP) technologies using CH<sub>4</sub> gas as a reducing source: Radial A-FSP (RA-FSP); and Axial A-FSP (AA-FSP). These are used for the control engineering of oxygen vacancies in the SrTiO<sub>3-x</sub> nanolattice. Based on X-ray photoelectron spectroscopy, Raman and thermogravimetry-differential thermal analysis, we discuss the role and the amount of the Vos in the so-produced nano-SrTiO<sub>3-x</sub>, correlating the properties of the nanolattice and energy-band structure of the SrTiO<sub>3-x</sub>. The present work further corroborates the versatility of FSP as a synthetic process and the potential future application of this process to engineer photocatalysts with oxygen vacancies in quantities that can be measured in kilograms. Materials science ; Thermogravimetry ; X-ray photoelectron spectroscopy ; Pyrolysis ; Thermal spraying ; Nanomaterials ; Raman spectroscopy ; Chemical engineering ; Oxygen ; Thermal stability ; Nanotechnology ; Chemistry ; Organic chemistry Electronic and Structural Properties of Oxides ; Advanced Photocatalysis Techniques ; Catalytic Processes in Materials Science
Authors: Mochamad Januar | Chengyu Lu | Horng‐Chih Lin | Tsung-Yu Huang | Chia‐Ming Yang | Kuo‐Kang Liu | Kou‐Chen Liu
Source: Materials Advances (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Unveiling the nature of room-temperature-fabricated p-type SnO thin films: the critical role of intermediate phases, lattice disorder, and oxygen interstitials This study showcases the use of ion-beam-assisted deposition for fabricating p-type SnO thin films at room temperature, which reveals crucial links between Hall mobility and lattice disorder, and between hole concentration and the relative content of interstitial oxygen. Materials science ; Oxygen ; Thin film ; Lattice (music) ; Condensed matter physics ; Chemical engineering ; Chemical physics ; Crystallography ; Nanotechnology ; Chemistry ; Physics ZnO doping and properties ; Gas Sensing Nanomaterials and Sensors ; Transition Metal Oxide Nanomaterials
Authors: Abqaat Naseer | Manuel Evaristo | Mitjan Kalin | A. Cavaleiro
Source: Surface and Coatings Technology (article, 2024-12-02)
Field: Materials Science — Materials Chemistry

Effect of silicon and oxygen co-doping on structure and properties of non‑hydrogenated amorphous carbon Introducing silicon and oxygen dopants into amorphous carbon (a-C) is known to improve its structural and functional properties, making it suitable for specialized applications. Yet, given the limited compositional control offered by the complex deposition methods, the relationship between dopant concentration and coating properties is not well understood. This study systematically investigates the effect of increasing silicon (0–30 at.%) and oxygen (0–20 at.%) content on structure, hardness, reduced modulus, and surface wettability of non‑hydrogenated a-C coatings, deposited by magnetron sputtering. The coating composition was controlled by adjusting the power applied to the silicon target and the oxygen gas flow rate during the sputtering process. Our results indicate that with increasing silicon content, the sp 3 /sp 2 fraction, hardness, reduced modulus, and surface energy progressively increased. Moreover, while high oxygen content, in general, promoted graphitization, leading to loss of mechanical properties, it also helped in reducing surface energy by terminating silicon bonds. Nonetheless, it was observed that the otherwise detrimental effect of oxygen doping on mechanical properties could be avoided by maintaining a low concentration of oxygen (~ 10 at.%), combined with high silicon content (> 18 at.%). This work establishes optimized doping conditions for tailoring the structure and properties of silicon and oxygen co-doped non‑hydrogenated a-C coatings, potentially extending their usage in protective and functional applications. • a-C:Si:O coatings with controlled stoichiometry were deposited via magnetron sputtering. • Increasing silicon concentration enhanced sp 3 /sp 2 fraction, hardness, and modulus. • High oxygen content (~20 at.%) reduced mechanical properties and surface energy. • A precise control of doping content enabled optimization of the structure, mechanical properties, and surface wettability. Amorphous silicon ; Materials science ; Doping ; Silicon ; Carbon fibers ; Oxygen ; Amorphous carbon ; Amorphous solid ; Chemical engineering ; Chemistry ; Optoelectronics ; Crystallography ; Crystalline silicon ; Composite material ; Organic chemistry ; Engineering Diamond and Carbon-based Materials Research ; Carbon Nanotubes in Composites ; Polymer Nanocomposite Synthesis and Irradiation
Authors: Shu‐Min Guo | Pengwei Xu | Armido Studer
Source: Angewandte Chemie (article, 2024-04-18)
Field: Chemistry — Organic Chemistry

<i>Meta</i>‐Selective Copper‐Catalyzed C−H Arylation of Pyridines and Isoquinolines through Dearomatized Intermediates Abstract C(sp 2 )−H functionalization offers an efficient strategy for the synthesis of various elaborated N ‐containing heteroarenes. Along these lines, oxazino pyridines that can be readily prepared from pyridines, have been introduced as powerful substrates in radical‐ and ionic‐mediated meta ‐C−H functionalization. However, the regioselective meta ‐C−H arylation of pyridines remains a great challenge. Herein, a copper‐catalyzed meta ‐selective C−H arylation of pyridines and isoquinolines through bench‐stable dearomatized intermediates is reported. Electrophilic aryl‐Cu(III) species, generated from readily accessible aryl I(III) reagents, enable the efficient meta ‐arylation of a broad range of pyridines and isoquinolines. The method also allows the meta ‐selective alkenylation of these heteroarenes using the corresponding alkenyl I(III)‐reagents. Late‐stage arylation of drug‐derived pyridines and larger‐scale experiments demonstrate the potential of this synthetic methodology. Catalysis ; Chemistry ; Copper ; Organic chemistry ; Combinatorial chemistry Catalytic C–H Functionalization Methods ; Asymmetric Hydrogenation and Catalysis ; Cyclopropane Reaction Mechanisms
Authors: Narendra Dinkar Kharat | Sushma Naharwal | Siva S. Panda | Kiran Bajaj | Rajeev Sakhuja
Source: Chemical Communications (article, 2024-01-01)
Field: Chemistry — Organic Chemistry

Iridium-catalyzed diacylmethylation of tyrosine and its peptides with sulfoxonium ylides Pyridyloxy-directed Ir(III)-catalyzed diacylmethylation of protected tyrosines was achieved with alkyl and (hetero)aryl sulfoxonium ylides, furnishing tyrosine-based unnatural amino acids in good yields. Furthermore, the late stage exemplification of the strategy was successfully accomplished in tyrosine-containing dipeptides, tripeptides and tetrapeptides in moderate yields. This methodology is distinguished by its site-selectivity, tolerance of sensitive functional groups, scalability, and retention of the chiral configuration for tyrosine motifs. Exemplification ; Catalysis ; Aryl ; Chemistry ; Alkyl ; Iridium ; Amino acid ; Tyrosine ; Combinatorial chemistry ; Pharmacophore ; Stereochemistry ; Organic chemistry ; Biochemistry Catalytic C–H Functionalization Methods ; Asymmetric Hydrogenation and Catalysis ; Chemical Synthesis and Analysis
Authors: Siyu Li | Leendert G.J. van der Ven | Santiago J. García | A. Catarina C. Esteves
Source: ACS Applied Polymer Materials (article, 2024-07-22)
Field: Materials Science — Polymers and Plastics

Healable Supracolloidal Nanocomposite Water-Borne Coatings Water-borne coatings often contain nanofillers to enhance their mechanical or optical properties. The aggregation of these fillers may, however, lead to undesired effects such as brittle and opaque coatings, reducing their performance and lifetime. By controlling the distribution and structural arrangement of the nanofillers in the coatings and inserting reversible chemical bonds, both the elasticity and strength of the coatings may be effectively improved, while healing properties, via the reversible chemistry, extend the coating's lifetime. Aqueous dispersions of polymer-core/silica-corona supracolloidal particles were used to prepare water-borne coatings. Polymer and silica nanoparticles were prefunctionalized with thiol/disulfide groups during the supracolloid assembly. Disulfide bridges were further established between a cross-linker and the supracolloids during drying and coating formation. The supracolloidal nanocomposite coatings were submitted to intentional (physical) damages, i.e., blunt and sharp surface scratches or cut through into two pieces, and subsequently UV irradiated to induce the recovery of the damage(s). The viscoelasticity and healing properties of the coatings were examined by dynamic, static, and surface mechanical analyses. The nanocomposite coatings showed a great extent of interfacial restoration of cut damage and surface scratches. The healing properties are strongly related to the coating's viscoelasticity and interfacial (re)activation of the disulfide bridges. Nanocomposite coatings with silica concentrations below their critical volume fraction show higher in situ healing efficiency, as compared to coatings with higher silica concentration. This work provides insights into the control of nanofillers distribution in water-borne coatings and strategies to increase the coating lifetime via mechanical damage recovery. Materials science ; Nanocomposite ; Coating ; Composite material ; Polymer ; Viscoelasticity ; Nanoparticle ; Brittleness ; Nanotechnology Polymer composites and self-healing ; Surface Modification and Superhydrophobicity ; Polymer Nanocomposites and Properties
Authors: Xiaotong Li | Lei Jiao | Ruimin Li | Xiangkun Jia | Chengjie Chen | Lijun Hu | Dongbo Yan | Yanling Zhai | Xiaoquan Lu
Source: Small (article, 2024-09-03)
Field: Chemistry — Organic Chemistry

Biomimetic Electronic Communication of Iodine Doped Single‐Atom Fe Site for Highly Active and Stable Dopamine Oxidation Rational design of highly active and stable catalysts for dopamine oxidation is still a great challenge. Herein, inspired by the catalytic pocket of natural enzymes, an iodine (I)-doped single Fe-site catalyst (I/Fe<sub>SA</sub>NC) is synthesized to mimic the catalytic center of heme enzymes in both geometrical and electronic structures, aiming to enhance dopamine (DA) oxidation. Experimental studies and theoretical calculations show that electronic communication between I and FeN<sub>5</sub> effectively modulates the electronic structure of the active site, greatly optimizing the overlap of Fe 3d and O 2p orbitals, thereby enhancing OH adsorption. In addition, the electronic communication induced by iodine doping attenuates the attack of proton hydrogen on the active center, thereby enhancing the stability of I/Fe<sub>SA</sub>NC. This work provides new insights into the design of highly active and stable single-atom catalysts and enhances the understanding of catalytic mechanisms for DA oxidation at the atomic scale. Active site ; Catalysis ; Active center ; Rational design ; Materials science ; Combinatorial chemistry ; Doping ; Atomic orbital ; Photochemistry ; Chemistry ; Nanotechnology ; Organic chemistry ; Physics ; Optoelectronics Nanomaterials for catalytic reactions ; Advanced Nanomaterials in Catalysis ; Electrocatalysts for Energy Conversion