jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Yinxiang Xu | Zhufeng Hu | Zhongbin Liu | Huajian Zhu | Yishu Yan | Junbo Xu | Chao Yang
Source: ACS Applied Nano Materials (article, 2021-02-04)
Field: Materials Science — Materials Chemistry

Molecular Simulations on Tuning the Interlayer Spacing of Graphene Nanoslits for C<sub>4</sub>H<sub>6</sub>/C<sub>4</sub>H<sub>10</sub> Separation There are great challenges in developing efficient membranes to replace the currently energy-intensive cryogenic distillation processes for purifying C4H6 from C4H6/C4H10 mixtures due to their similar physical and chemical properties. Here, we investigated the performance of graphene slits with different interlayer spacings for C4H6/C4H10 separation via molecular simulations. The results demonstrate that the 3.4-Å-interlayer-spacing graphene slit only allows the penetration of C4H6 due to the size sieving effect and the permeance of C4H6 is up to 2.09 × 106 GPU. When the interlayer spacing increases to 3.6–6.8 Å, the graphene slits still exhibit the preferential penetration for C4H6 over C4H10 due to the π–π adsorption interaction between graphene sheets and C4H6. Surprisingly, the graphene slits (>10.2 Å) exhibit the preferential penetration for C4H10 over C4H6 owing to the diffusivity of C4H10 being much larger than that of C4H6 under confined conditions. In conclusion, by fine-tuning the interlayer spacing of graphene slits, the dominant separation mechanism is switched in the order of size sieving, thermodynamic adsorption, and dynamic diffusion, thereby achieving the controllable regulation of the preferential permeation from C4H6 to C4H10. C4H10-selective membranes are of great significance for energy saving. The tuning strategy is expected to be applied in different paraffin/olefin separation scenarios such as high-content and low-content olefin feedstocks. Graphene ; Permeance ; Materials science ; Adsorption ; Membrane ; Distillation ; Olefin fiber ; Penetration (warfare) ; Chemical engineering ; Thermal diffusivity ; Chemical physics ; Permeation ; Nanotechnology ; Composite material ; Chemistry ; Chromatography ; Thermodynamics ; Organic chemistry ; Polymer Graphene research and applications ; Membrane Separation Technologies ; Membrane Separation and Gas Transport
Authors: A. G. Kunjomana | J. Bibin | S. Varadharajaperumal | M. Teena
Source: Vacuum (article, 2021-06-16)
Field: Materials Science — Materials Chemistry

Control of physical vapor deposition and architecture of stoichiometric SnSe heterojunction structures for solar cells Materials science ; X-ray photoelectron spectroscopy ; Crystallinity ; Heterojunction ; Crystallite ; Raman spectroscopy ; Band gap ; Chemical engineering ; Chemical vapor deposition ; Stoichiometry ; Solar cell ; Chemical bath deposition ; Nanotechnology ; Analytical Chemistry (journal) ; Optoelectronics ; Chemistry ; Composite material ; Optics Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films ; Copper-based nanomaterials and applications
Authors: Shengxia Zhang | Peipei Hu | Lijun Xu | Hailong Chen | Maaz Khan | Pengfei Zhai | Zongzhen Li | Li Liu | Wensi Ai | Jian Zeng | Jie Liu
Source: The Journal of Physical Chemistry C (article, 2021-09-10)
Field: Materials Science — Materials Chemistry

Exciton Transitions in Monolayer WS<sub>2</sub> Activated by Swift Heavy Ion Irradiation The emergence of monolayer transition metal dichalcogenides (TMDCs) has provided a favorable platform for exploring a broad range of novel optoelectronic device applications and quantum phenomena due to their remarkable physical and chemical characteristics. Understanding the transition and motion of excitons in TMDCs is of fundamental interest for their optoelectronic devices. Here, we demonstrate the exciton transition in monolayer WS2 that can be fine-tuned by swift heavy ion (SHI) irradiation. The dependence of trion and exciton emissions on SHI irradiation in the as-transferred and as-grown monolayer WS2 was investigated by micro photoluminescence (PL) spectra where different PL responses were monitored. The trion-to-exciton transition in the as-transferred WS2 monolayer was ascribed to SHI irradiation that resulted in charge localization and pre-existing defect annealing, whereas the exciton-to-trion transition in the as-grown WS2 monolayer was attributed to the competition of charge localization and charge transfer caused by SHI irradiation. Femtosecond transient absorption measurements were performed to study the exciton relaxation dynamics in SHI-irradiated WS2, and it was shown that defect-assisted recombination dominates the exciton relaxation process for SHI-irradiated WS2. These results open up new opportunities to manipulate and tune the optical properties of two-dimensional TMDCs, which are of special importance for the development of optoelectronic and valleytronic devices. Trion ; Exciton ; Monolayer ; Photoluminescence ; Irradiation ; Swift heavy ion ; Materials science ; Femtosecond ; Charge carrier ; Relaxation (psychology) ; Heterojunction ; Ion ; Optoelectronics ; Condensed matter physics ; Chemistry ; Nanotechnology ; Physics ; Optics ; Fluence ; Laser 2D Materials and Applications ; Perovskite Materials and Applications ; Advanced biosensing and bioanalysis techniques
Authors: J. A. Sekhar
Source: Entropy (article, 2021-08-22)
Field: Materials Science — Materials Chemistry

Self-Organization, Entropy Generation Rate, and Boundary Defects: A Control Volume Approach Self-organization that leads to the discontinuous emergence of optimized new patterns is related to entropy generation and the export of entropy. Compared to the original pattern that the new, self-organized pattern replaces, the new features could involve an abrupt change in the pattern-volume. There is no clear principle of pathway selection for self-organization that is known for triggering a particular new self-organization pattern. The new pattern displays different types of boundary-defects necessary for stabilizing the new order. Boundary-defects can contain high entropy regions of concentrated chemical species. On the other hand, the reorganization (or refinement) of an established pattern is a more kinetically tractable process, where the entropy generation rate varies continuously with the imposed variables that enable and sustain the pattern features. The maximum entropy production rate (MEPR) principle is one possibility that may have predictive capability for self-organization. The scale of shapes that form or evolve during self-organization and reorganization are influenced by the export of specific defects from the control volume of study. The control volume (CV) approach must include the texture patterns to be located inside the CV for the MEPR analysis to be applicable. These hypotheses were examined for patterns that are well-characterized for solidification and wear processes. We tested the governing equations for bifurcations (the onset of new patterns) and for reorganization (the fine tuning of existing patterns) with published experimental data, across the range of solidification morphologies and nonequilibrium phases, for metallic glass and featureless crystalline solids. The self-assembling features of surface-texture patterns for friction and wear conditions were also modeled with the entropy generation (MEPR) principle, including defect production (wear debris). We found that surface texture and entropy generation in the control volume could be predictive for self-organization. The main results of this study provide support to the hypothesis that self-organized patterns are a consequence of the maximum entropy production rate per volume principle. Patterns at any scale optimize a certain outcome and have utility. We discuss some similarities between the self-organization behavior of both inanimate and living systems, with ideas regarding the optimizing features of self-organized pattern features that impact functionality, beauty, and consciousness. Statistical physics ; Configuration entropy ; Entropy (arrow of time) ; Self-organization ; Pattern formation ; Entropy rate ; Non-equilibrium thermodynamics ; Computer science ; Materials science ; Principle of maximum entropy ; Thermodynamics ; Physics ; Artificial intelligence ; Joint quantum entropy Material Dynamics and Properties ; Adhesion, Friction, and Surface Interactions ; Theoretical and Computational Physics
Authors: Ilona Pyszka | Zdzisław Kucybała | Beata Jędrzejewska
Source: Materials (article, 2021-06-04)
Field: Chemistry — Organic Chemistry

Effective Singlet Oxygen Sensitizers Based on the Phenazine Skeleton as Efficient Light Absorbers in Dye Photoinitiating Systems for Radical Polymerization of Acrylates A series of dyes based on the phenazine skeleton were synthesized. They differed in the number of conjugated double bonds, the arrangement of aromatic rings (linear and/or angular system), as well as the number and position of nitrogen atoms in the molecule. These compounds were investigated as potential singlet oxygen sensitizers and visible light absorbers in dye photoinitiating systems for radical polymerization. The quantum yield of the singlet oxygen formation was determined by the comparative method based on the <sup>1</sup>H NMR spectra recorded for the tested dyes in the presence of 2,3-diphenyl-<i>p</i>-dioxene before and after irradiation. The quantum yield of the triplet state formation was estimated based on the transient absorption spectra recorded using the nanosecond flash photolysis technique. The effectiveness of the dye photoinitiating system was characterized by the initial rate of trimethylolpropane triacrylate (<i>TMPTA</i>) polymerization. In the investigated photoinitiating systems, the sensitizer was an electron acceptor, whereas the co-initiator was an electron donor. The effectiveness of TMPTA photoinitiated polymerization clearly depended on the arrangement of aromatic rings and the number of nitrogen atoms in the modified phenazine structure as well as the quantum yield of the triplet state formation of the photosensitizer in the visible light region. Photochemistry ; TMPTA ; Singlet oxygen ; Polymerization ; Quantum yield ; Triplet state ; Chemistry ; Photosensitizer ; Flash photolysis ; Photopolymer ; Materials science ; Photoinitiator ; Molecule ; Oxygen ; Fluorescence ; Organic chemistry ; Reaction rate constant ; Monomer ; Polymer ; Kinetics Photopolymerization techniques and applications ; Photodynamic Therapy Research Studies ; TiO2 Photocatalysis and Solar Cells
Authors: Mariam Y. Al-Enezi | Elizabeth John | Yehia A. Ibrahim | Nouria A. Al‐Awadi
Source: RSC Advances (article, 2021-01-01)
Field: Chemistry — Organic Chemistry

Highly efficient Ru(<scp>ii</scp>)–alkylidene based Hoveyda–Grubbs catalysts for ring-closing metathesis reactions Three novel phosphine-free Ru-alkylidenes (7a-7c) have been synthesized and utilized as efficient catalysts for ring closing metathesis (RCM) reaction. Spectroscopic data, <i>i.e.</i> NMR and HRMS, along with single crystal X-ray diffraction analysis, were used to confirm their chemical structures. The tosylated carbenoid 7b showed the highest efficiency in cyclizing different acyclic diene substrates. RCM of various (un)substituted <i>N</i>,<i>N</i>-diallylaniline derivatives and stereoselective RCM of different macromolecular dienes were well tolerated using only a catalytic amount (0.5-2.0 mol%) of the additive catalyst (7b) as compared to the well-known Grubbs (II) and Hoveyda-Grubbs (II) catalysts. Catalysis ; Metathesis ; Chemistry ; Salt metathesis reaction ; Ring-closing metathesis ; Phosphine ; Diene ; Carbenoid ; Medicinal chemistry ; Combinatorial chemistry ; Stereochemistry ; Organic chemistry ; Polymerization ; Rhodium Synthetic Organic Chemistry Methods ; Cyclopropane Reaction Mechanisms ; Chemical Synthesis and Analysis
Authors: Irini Gerges | Margherita Tamplenizza | Federico Martello | Stefano Koman | Giulia Chincarini | Camilla Recordati | Mariacaterina Tamplenizza | Scott A. Guelcher | Maurizio Crestani | Alessandro Tocchio
Source: Scientific Reports (article, 2021-06-25)
Field: Materials Science — Biomaterials

Conditioning the microenvironment for soft tissue regeneration in a cell free scaffold The use of cell-free scaffolds for the regeneration of clinically relevant volumes of soft tissue has been challenged, particularly in the case of synthetic biomaterials, by the difficulty of reconciling the manufacturing and biological performance requirements. Here, we investigated in vivo the importance of biomechanical and biochemical cues for conditioning the 3D regenerative microenvironment towards soft tissue formation. In particular, we evaluated the adipogenesis changes related to 3D mechanical properties by creating a gradient of 3D microenvironments with different stiffnesses using 3D Poly(Urethane-Ester-ether) PUEt scaffolds. Our results showed a significant increase in adipose tissue proportions while decreasing the stiffness of the 3D mechanical microenvironment. This mechanical conditioning effect was also compared with biochemical manipulation by loading extracellular matrices (ECMs) with a PPAR-γ activating molecule. Notably, results showed mechanical and biochemical conditioning equivalency in promoting adipose tissue formation in the conditions tested, suggesting that adequate mechanical signaling could be sufficient to boost adipogenesis by influencing tissue remodeling. Overall, this work could open a new avenue in the design of synthetic 3D scaffolds for microenvironment conditioning towards the regeneration of large volumes of soft and adipose tissue, with practical and direct implications in reconstructive and cosmetic surgery. Scaffold ; Regeneration (biology) ; Adipogenesis ; Adipose tissue ; Tissue engineering ; Soft tissue ; Conditioning ; Biomedical engineering ; Cell biology ; Extracellular matrix ; Chemistry ; Regenerative medicine ; Cell ; Biology ; Biochemistry ; Pathology ; Medicine Electrospun Nanofibers in Biomedical Applications ; Tissue Engineering and Regenerative Medicine ; 3D Printing in Biomedical Research
Authors: Brandon Andrade‐Gagnon | Marilyne Bélanger‐Bouliga | Phuong Nguyen | Thi Hong Diep Nguyen | Steve Bourgault | Ali Nazemi
Source: Nanomaterials (article, 2021-01-10)
Field: Materials Science — Surfaces, Coatings and Films

Degradable Spirocyclic Polyacetal-Based Core-Amphiphilic Assemblies for Encapsulation and Release of Hydrophobic Cargo Polymeric nanomaterials that degrade in acidic environments have gained considerable attention in nanomedicine for intracellular drug delivery and cancer therapy. Among various acid-degradable linkages, spirocyclic acetals have rarely been used to fabricate such vehicles. In addition to acid sensitivity, they benefit from conformational rigidity that is otherwise not attainable by their non-spirocyclic analogs. Herein, amphiphilic spirocyclic polyacetals are synthesized by Cu-catalyzed alkyne-azide "click" polymerization. Unlike conventional block copolymers, which often form core-shell structures, these polymers self-assemble to form core amphiphilic assemblies capable of encapsulating Nile red as a hydrophobic model drug. In vitro experiments show that while release from these materials can occur at neutral pH with preservation of their integrity, acidic pH accelerates efficient cargo release and leads to the complete degradation of assemblies. Moreover, cellular assays reveal that these materials are fully cytocompatible, interact with the plasma membrane, and can be internalized by cells, rendering them as potential candidates for cancer therapy and/or drug delivery. Amphiphile ; Encapsulation (networking) ; Materials science ; Polymer science ; Chemical engineering ; Polymer chemistry ; Chemistry ; Polymer ; Composite material ; Copolymer ; Computer science ; Engineering Surface Modification and Superhydrophobicity ; Advanced Polymer Synthesis and Characterization ; Electrospun Nanofibers in Biomedical Applications
Authors: Thomas Comerford | Eli Zysman‐Colman
Source: Small Science (article, 2021-06-04)
Field: Materials Science — Materials Chemistry

Supramolecular Assemblies Showing Thermally Activated Delayed Fluorescence Supramolecular assemblies based on luminescent components offer significant advantages over their discrete counterparts, including improved quantum yields, stability, and tunability. Following interest as advanced optoelectronic materials, thermally activated delayed fluorescence (TADF) emitters are incorporated into a range of supramolecular structures. Herein, a summary of the known examples of emissive supramolecular systems that operate via a TADF mechanism with comparisons, where possible, with their discrete counterparts is presented. While the types of supramolecular structures are diverse, there are limited examples shown for each class. With the increase in photophysical performance and/or emergence of new photochemical properties upon going from molecular to supramolecular, the potential that these systems hold becomes apparent. Supramolecular chemistry ; Fluorescence ; Luminescence ; Materials science ; Nanotechnology ; Supramolecular assembly ; Photochemistry ; Optoelectronics ; Chemistry ; Molecule ; Physics ; Organic chemistry ; Optics Luminescence and Fluorescent Materials ; Synthesis and Properties of Aromatic Compounds ; Organic Light-Emitting Diodes Research
Authors: Jacquelyn G. Egan | Glen Brodie | Daniel McDowall | Andrew J. Smith | Charlotte J. C. Edwards‐Gayle | Emily R. Draper
Source: Materials Advances (article, 2021-01-01)
Field: Materials Science — Biomaterials

Impact of subtle change in branched amino acid on the assembly and properties of perylene bisimides hydrogels We investigate how apparent slight changes to the chemical structure of amino acid-functionalised perylene bisimides (PBIs) affect the self-assembled aggregates formed and their resulting physical and optical properties. Perylene ; Self-healing hydrogels ; Chemistry ; Polymer chemistry ; Photochemistry ; Chemical engineering ; Materials science ; Molecule ; Organic chemistry Supramolecular Self-Assembly in Materials ; Polydiacetylene-based materials and applications ; Conducting polymers and applications
Authors: Anca‐Dana Bendrea | Luminita Cianga | Gabriela Liliana Ailiesei | Elena‐Laura Ursu | Demet Göen Colak | Ioan Cianga
Source: Polymers (article, 2021-08-14)
Field: Chemistry — Organic Chemistry

3,4-Ethylenedioxythiophene (EDOT) End-Group Functionalized Poly-ε-caprolactone (PCL): Self-Assembly in Organic Solvents and Its Coincidentally Observed Peculiar Behavior in Thin Film and Protonated Media End-group functionalization of homopolymers is a valuable way to produce high-fidelity nanostructured and functional soft materials when the structures obtained have the capacity for self-assembly (SA) encoded in their structural details. Herein, an end-functionalized PCL with a π-conjugated EDOT moiety, (<b>EDOT-PCL</b>), designed exclusively from hydrophobic domains, as a functional "hydrophobic amphiphile", was synthesized in the bulk ROP of ε-caprolactone. The experimental results obtained by spectroscopic methods, including NMR, UV-vis, and fluorescence, using DLS and by AFM, confirm that in solvents with extremely different polarities (chloroform and acetonitrile), <b>EDOT-PCL</b> presents an interaction- and structure-based bias, which is strong and selective enough to exert control over supramolecular packing, both in dispersions and in the film state. This leads to the diversity of SA structures, including spheroidal, straight, and helical rods, as well as orthorhombic single crystals, with solvent-dependent shapes and sizes, confirming that <b>EDOT-PCL</b> behaves as a "block-molecule". According to the results from AFM imaging, an unexpected transformation of micelle-type nanostructures into single 2D lamellar crystals, through breakout crystallization, took place by simple acetonitrile evaporation during the formation of the film on the mica support at room temperature. Moreover, <b>EDOT-PCL's</b> propensity for spontaneous oxidant-free oligomerization in acidic media was proposed as a presumptive answer for the unexpected appearance of blue color during its dissolution in CDCl<sub>3</sub> at a high concentration. FT-IR, UV-vis, and fluorescence techniques were used to support this claim. Besides being intriguing and unforeseen, the experimental findings concerning <b>EDOT-PCL</b> have raised new and interesting questions that deserve to be addressed in future research. Materials science ; Caprolactone ; Chemical engineering ; Protonation ; Polymer chemistry ; Poly(3,4-ethylenedioxythiophene) ; Thin film ; Group (periodic table) ; End-group ; Organic chemistry ; Nanotechnology ; Layer (electronics) ; Composite material ; Copolymer ; Polymer ; Chemistry ; PEDOT:PSS Advanced Polymer Synthesis and Characterization ; Supramolecular Self-Assembly in Materials ; Conducting polymers and applications
Authors: Márton Szabados | Adél Anna Ádám | Zsolt Kása | Kornélia Baán | Róbert Mucsi | András Sápi | Zoltán Kónya | Ákos Kukovecz | Pál Sipos
Source: Materials (article, 2021-08-27)
Field: Materials Science — Materials Chemistry

M(II)Al4 Type Layered Double Hydroxides—Preparation Using Mechanochemical Route, Structural Characterization and Catalytic Application The synthesis of the copper-poor and aluminum-rich layered double hydroxides (LDHs) of the CuAl<sub>4</sub> type was optimized in detail in this work, by applying an intense mechanochemical treatment to activate the gibbsite starting reagent. The phase-pure forms of these LDHs were prepared for the first time; using copper nitrate and perchlorate salts during the syntheses turned out to be the key to avoiding the formation of copper hydroxide sideproducts. Based on the use of the optimized syntheses parameters, the preparation of layered triple and multiple hydroxides was also attempted using Ni(II), Co(II), Zn(II) and even Mg(II) ions. These studies let us identify the relative positions of the incorporating cations in the well-known selectivity series as Ni<sup>2+</sup> >> Cu<sup>2+</sup> >> Zn<sup>2+</sup> > Co<sup>2+</sup> >> Mg<sup>2+</sup>. The solids formed were characterized by using powder X-ray diffractometry, UV-Vis diffuse reflectance spectroscopy, Fourier-transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. The catalytic potential of the samples was investigated in carbon monoxide oxidation reactions at atmospheric pressure, supported by an in situ diffuse reflectance infrared spectroscopy probe. All solids proved to be active and the combination of the nickel and cobalt incorporation (which resulted in a NiCoAl<sub>8</sub> layered triple hydroxide) brought outstanding benefits regarding low-temperature oxidation and increased carbon monoxide conversion values. Layered double hydroxides ; Hydroxide ; Diffuse reflectance infrared fourier transform ; Catalysis ; Copper ; Inorganic chemistry ; Carbon monoxide ; Nickel ; Reagent ; Fourier transform infrared spectroscopy ; Cobalt ; Infrared spectroscopy ; Chemistry ; Materials science ; Chemical engineering ; Organic chemistry ; Photocatalysis Layered Double Hydroxides Synthesis and Applications ; Magnesium Oxide Properties and Applications ; Inorganic Chemistry and Materials
Authors: Victorio Cadierno
Source: Catalysts (article, 2021-05-19)
Field: Chemistry — Organic Chemistry

Recent Advances in Organometallic Chemistry and Catalysis The use of organometallic compounds in organic chemistry is one of the cornerstones of the modern synthetic methodology for the activation and generation of new bonds in a molecule [...] Organometallic chemistry ; Chemistry ; Nanotechnology ; Organic chemistry ; Combinatorial chemistry ; Catalysis ; Materials science Synthetic Organic Chemistry Methods ; Asymmetric Synthesis and Catalysis ; Oxidative Organic Chemistry Reactions