jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Fancheng Meng | Yahui Liu | Lina Wang | Desheng Chen | Hongxin Zhao | Yulan Zhen | Jing Chen | Tao Qi
Source: Materials (article, 2021-04-27)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Vibrational Spectral Analysis of Natisite (Na2TiSiO5) and its Structure Evolution in Water and Sulfuric Acid Solutions Natisite (Na<sub>2</sub>TiSiO<sub>5</sub>) is a layered sodium titanosilicate containing TiO<sub>5</sub> square pyramids. The structure evolution of natisite in water and acid solutions is the basis for its potential applications. With Na<sub>2</sub>SiO<sub>3</sub> as the silicon source, natisite with the shape of the square sheet was selectively prepared from the hydrothermal method with 14.3 mol/L NaOH solution at 240 °C. Natisite has 20 Raman active modes and 22 infrared active modes from the first-principles calculations within density functional theory, and the calculated Raman and infrared spectra agree well with the experimental ones. The characteristic Raman peak at 844 cm<sup>-1</sup> is caused by the symmetric stretching of the apical Ti-O bond in the TiO<sub>5</sub> unit, assigning to <i>A</i><sub>1g</sub> and <i>B</i><sub>2g</sub> modes. Natisite remains relatively stable in water with a sodium leaching percentage of lower than 6%. When washing with sulfuric acid solutions, the interlayer spacing of natisite is reduced due to the extensive removal of sodium ions, and an intermediate composed of SiO<sub>4</sub> and newly formed TiO<sub>6</sub> units may be formed. Moreover, after washing with water and acid solutions, 95.5%, 63.4%, and 35.2% of Na, Si, and Ti in natisite can be leached in total, respectively, resulting in the structural disintegration of natisite. Sulfuric acid ; Raman spectroscopy ; Leaching (pedology) ; Density functional theory ; Infrared ; Sodium ; Hydrothermal circulation ; Chemistry ; Ion ; Infrared spectroscopy ; Materials science ; Inorganic chemistry ; Analytical Chemistry (journal) ; Chemical engineering ; Computational chemistry ; Organic chemistry ; Soil water ; Optics ; Geology ; Physics Crystal Structures and Properties ; Glass properties and applications ; Nuclear materials and radiation effects
Authors: Adriana Yazik | Nur Azira Tukiran
Source: Malaysian Journal of Science Health & Technology (review, 2021-10-01)
Field: Materials Science — Biomaterials

Characterization of Polyvinyl Alcohol (PVA) as Antimicrobial Biocomposite Film: A Review Packaging is a critical process in the food industry because it is used to prevent spoilage, extend shelf-life, and provide an attractive presentation of the food product. Plastic packaging is used all over the world, and its production is increasing year after year. It comes in a variety of colours and designs. However, it has caused serious environmental problems, particularly to the ocean that has become a place for discarded plastic packaging. To address this issue, biodegradable packaging was developed to replace the use of plastic packaging because it helps to reduce environmental impact and waste management costs. Biodegradable packaging is also known as environmentally friendly packaging because it can be degraded into carbon dioxide, water, inorganic compounds, and biomass by microorganisms, algae, fungi, as well as enzyme catalysts. Biodegradable biocomposite film such as starch, cellulose, chitosan, and polyvinyl alcohol (PVA) is required to produce biodegradable packaging. Therefore, this paper aims to characterize PVA as a biocomposite film in biodegradable packaging. PVA has excellent properties to form films, as well as biodegradable, abundant in the environment, and cost-effective. However, it has some limitations in terms of thickness and mechanical properties; thus, the incorporation of PVA with essential oils and fiber is required to improve its mechanical properties, thickness, and provide antimicrobial properties to the packaging. Biocomposite ; Food packaging ; Materials science ; Polyvinyl alcohol ; Environmentally friendly ; Active packaging ; Polylactic acid ; Biodegradation ; Waste management ; Pulp and paper industry ; Composite material ; Food science ; Chemistry ; Polymer ; Composite number ; Organic chemistry ; Engineering Nanocomposite Films for Food Packaging ; biodegradable polymer synthesis and properties ; Microplastics and Plastic Pollution
Authors: Łukasz Hetmańczyk | E. A. Goremychkin | J. Waliszewski | Mikhail V. Vener | Paweł Lipkowski | Peter M. Tolstoy | Aleksander Filarowski
Source: Molecules (article, 2021-08-20)
Field: Chemistry — Spectroscopy

Spectroscopic Identification of Hydrogen Bond Vibrations and Quasi-Isostructural Polymorphism in N-Salicylideneaniline The <i>ortho</i>-hydroxy aryl <i>Schiff</i> base 2-[(E)-(phenylimino)methyl]phenol and its deutero-derivative have been studied by the inelastic incoherent neutron scattering (IINS), infrared (IR) and Raman experimental methods, as well as by Density Functional Theory (DFT) and Density-Functional Perturbation Theory (DFPT) simulations. The assignments of vibrational modes within the 3500-50 cm<sup>-1</sup> spectral region made it possible to state that the strong hydrogen bond in the studied compound can be classified as the so-called quasi-aromatic bond. The isotopic substitution supplemented by the results of DFT calculations allowed us to identify vibrational bands associated with all five major hydrogen bond vibrations. Quasi-isostructural polymorphism of 2-[(E)-(phenylimino)methyl]phenol (<b>SA</b>) and 2-[(E)-(phenyl-D<sub>5</sub>-imino)methyl]phenol (<b>SA-C<sub>6</sub>D<sub>5</sub></b>) has been studied by powder X-ray diffraction in the 20-320 K temperature range. Isostructural ; Chemistry ; Density functional theory ; Hydrogen bond ; Crystallography ; Raman spectroscopy ; Schiff base ; Infrared spectroscopy ; Inelastic neutron scattering ; Ground state ; Computational chemistry ; Crystal structure ; Inelastic scattering ; Molecule ; Scattering ; Atomic physics ; Physics ; Organic chemistry Molecular Spectroscopy and Structure ; Crystallography and molecular interactions ; Nonlinear Optical Materials Research
Authors: Iveta Vilímová | Karolı́na Šišková
Source: Nanomaterials (article, 2021-08-26)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Distinctly Different Morphologies of Bimetallic Au-Ag Nanostructures and Their Application in Submicromolar SERS-Detection of Free Base Porphyrin Core-shell Au-Ag nanostructures (Au-AgNSs) are prepared by a seed-meditated growth, i.e., by a two-step process. The synthetic parameters greatly influence the morphologies of the final bimetallic Au-AgNSs, their stability and application potential as surface-enhanced Raman scattering (SERS) substrates. Direct comparison of several types of Au NPs possessing different surface species and serving as seeds in Au-AgNSs synthesis is the main objective of this paper. Borohydride-reduced (with varying stages of borohydride hydrolysis) and citrate-reduced Au NPs were prepared and used as seeds in Au-AgNSs generation. The order of reactants in seed-mediated growth procedure represents another key factor influencing the final Au-AgNSs characteristics. Electronic absorption spectra, dynamic light scattering, zeta potential measurements, energy dispersive spectroscopy and transmission electron microscopy were employed for Au-AgNSs characterization. Subsequently, possibilities and limitations of SERS-detection of unperturbed cationic porphyrin, 5,10,15,20-tetrakis(1-methyl-4-pyridyl)21H,23H-porphine (TMPyP), were investigated by using these Au-AgNSs. Only the free base (unperturbed) SERS spectral form of TMPyP is detected in all types of Au-AgNSs. It reports about a well-developed envelope of organic molecules around each Au-AgNSs which prevents metalation from occuring. TMPyP, attached via ionic interaction, was successfully detected in 10 nM concentration due to Au-AgNSs. Porphyrin ; Cationic polymerization ; Sodium borohydride ; Raman scattering ; Materials science ; Nanostructure ; Zeta potential ; Ionic bonding ; Bimetallic strip ; Borohydride ; Raman spectroscopy ; Free base ; Transmission electron microscopy ; Absorption spectroscopy ; Chemical engineering ; Nanoparticle ; Photochemistry ; Chemistry ; Nanotechnology ; Physical chemistry ; Organic chemistry ; Polymer chemistry ; Metal ; Catalysis ; Ion Gold and Silver Nanoparticles Synthesis and Applications ; Electrochemical Analysis and Applications ; Nanocluster Synthesis and Applications
Authors: George Antonaropoulos | Marianna Vasilakaki | K. N. Trohidou | Vincenzo Iannotti | G. Ausanio | Milinda Abeykoon | Emil S. Božin | Alexandros Lappas
Source: Nanoscale (article, 2021-11-30)
Field: Materials Science — Materials Chemistry

Tailoring defects and nanocrystal transformation for optimal heating power in bimagnetic Co<sub><i>y</i></sub>Fe<sub>1−<i>y</i></sub>O@Co<sub><i>x</i></sub>Fe<sub>3−<i>x</i></sub>O<sub>4</sub>particles The effects of cobalt incorporation in spherical heterostructured iron oxide nanocrystals (NCs) of sub-critical size have been explored by colloidal chemistry methods. Synchrotron X-ray total scattering methods suggest that cobalt (Co) substitution in rock salt iron oxide NCs tends to remedy their vacant iron sites, offering a higher degree of resistance to oxidative conversion. Self-passivation still creates a spinel-like shell, but with a higher volume fraction of the rock salt Co-containing phase in the core. The higher divalent metal stoichiometry in the rock salt phase, with increasing Co content, results in a population of unoccupied tetrahedral metal sites in the spinel part, likely through oxidative shell creation, involving an ordered defect-clustering mechanism, directly correlated to core stabilization. To shed light on the effects of Co-substitution and atomic-scale defects (vacant sites), Monte Carlo simulations suggest that the designed NCs, with desirable, enhanced magnetic properties (<i>cf.</i> exchange bias and coercivity), are developed with magnetocrystalline anisotropy which increases due to a relatively low content of Co ions in the lattice. The growth of optimally performing candidates combines also a strongly exchange-coupled system, secured through a high volumetric ratio rock salt phase, interfaced by a not so defective spinel shell. In view of these requirements, specific absorption rate (SAR) calculations demonstrate that the rock salt core sufficiently protected from oxidation and the heterostructure preserved over time, play a key role in magnetically mediated heating efficacies, for potential use of such NCs in magnetic hyperthermia applications. Nanocrystal ; Materials science ; Transformation (genetics) ; Crystallography ; Nanotechnology ; Chemistry Magnetic Properties and Synthesis of Ferrites ; Magnetic properties of thin films ; Iron oxide chemistry and applications
Authors: Sabrina Spiller | Tom Wippold | Kathrin Bellmann‐Sickert | Sandra Franz | Anja Saalbach | Ulf Anderegg | Annette G. Beck‐Sickinger
Source: Pharmaceutics (article, 2021-10-01)
Field: Materials Science — Biomaterials

Protease-Triggered Release of Stabilized CXCL12 from Coated Scaffolds in an Ex Vivo Wound Model Biomaterials are designed to improve impaired healing of injured tissue. To accomplish better cell integration, we suggest to coat biomaterial surfaces with bio-functional proteins. Here, a mussel-derived surface-binding peptide is used and coupled to CXCL12 (stromal cell-derived factor 1α), a chemokine that activates CXCR4 and consequently recruits tissue-specific stem and progenitor cells. CXCL12 variants with either non-releasable or protease-mediated-release properties were designed and compared. Whereas CXCL12 was stabilized at the N-terminus for protease resistance, a C-terminal linker was designed that allowed for specific cleavage-mediated release by matrix metalloproteinase 9 and 2, since both enzymes are frequently found in wound fluid. These surface adhesive CXCL12 derivatives were produced by expressed protein ligation. Functionality of the modified chemokines was assessed by inositol phosphate accumulation and cell migration assays. Increased migration of keratinocytes and primary mesenchymal stem cells was demonstrated. Immobilization and release were studied for bioresorbable PCL-<i>co</i>-LC scaffolds, and accelerated wound closure was demonstrated in an ex vivo wound healing assay on porcine skin grafts. After 24 h, a significantly improved CXCL12-specific growth stimulation of the epithelial tips was already observed. The presented data display a successful application of protein-coated biomaterials for skin regeneration. Wound healing ; Homing (biology) ; Ex vivo ; Chemistry ; Protease ; Mesenchymal stem cell ; Cell biology ; Stromal cell ; In vivo ; Regeneration (biology) ; Extracellular matrix ; Progenitor cell ; Chemokine ; Stem cell ; In vitro ; Biochemistry ; Biology ; Enzyme ; Immunology ; Receptor ; Cancer research Silk-based biomaterials and applications ; Antimicrobial Peptides and Activities ; Wound Healing and Treatments
Authors: Juhae Park | Abelardo Ramírez-Hernández | Vikram Thapar | Su‐Mi Hur
Source: Polymers (article, 2021-03-19)
Field: Materials Science — Materials Chemistry

Mesoscale Simulations of Polymer Solution Self-Assembly: Selection of Model Parameters within an Implicit Solvent Approximation Coarse-grained modeling is an outcome of scientific endeavors to address the broad spectrum of time and length scales encountered in polymer systems. However, providing a faithful structural and dynamic characterization/description is challenging for several reasons, particularly in the selection of appropriate model parameters. By using a hybrid particle- and field-based approach with a generalized energy functional expressed in terms of density fields, we explore model parameter spaces over a broad range and map the relation between parameter values with experimentally measurable quantities, such as single-chain scaling exponent, chain density, and interfacial and surface tension. The obtained parameter map allows us to successfully reproduce experimentally observed polymer solution assembly over a wide range of concentrations and solvent qualities. The approach is further applied to simulate structure and shape evolution in emulsified block copolymer droplets where concentration and domain shape change continuously during the process. Scaling ; Statistical physics ; Range (aeronautics) ; Surface tension ; Mesoscale meteorology ; Materials science ; Polymer ; Exponent ; Characterization (materials science) ; Thermodynamics ; Physics ; Nanotechnology ; Mathematics ; Geometry Block Copolymer Self-Assembly ; Advanced Polymer Synthesis and Characterization ; Polymer Surface Interaction Studies
Authors: Berta Casanovas | Oriol Porcar-Santos | Saskia Speed | Ramón Vicente | Mercè Font-Bardı́a | M.S. El Fallah
Source: Magnetochemistry (article, 2021-09-10)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Field-Induced SMM and Vis/NIR Luminescence on Mononuclear Lanthanide Complexes with 9-Anthracenecarboxylate and 2,2′:6,2″-Terpyridine Five new mononuclear lanthanide complexes are synthesized by adding the several lanthanide nitrate hexahydrate salts, which for lanthanide (Ln) are Eu, Tb, Dy, Er, and Yb, with 9-anthracenecarboxylic acid (9-Hanthc) and 2,2′:6,2″-terpyridine (TPY) in mixed solution of methanol and dimethylformamide (DMF). The general formula is [Eu(9-anthc)3(TPY)(DMF)]·H2O (1Eu) where Eu(III) is ennea-coordinated or [Ln(9-anthc)3(TPY)(H2O)]·H2O·DMF (Ln = Tb (2Tb), Dy (3Dy), Er (4Er), and Yb (5Yb)) where Ln(III) is octa-coordinated. For compounds 3Dy, 4Er, and 5Yb, the dynamic ac magnetic study indicated field-induced single molecule magnet (SMM) behavior. The photoluminescence studies in the solid state of these complexes show the sensitization of 4f-4f transitions for 4Er and 5Yb in the NIR region. Lanthanide ; Terpyridine ; Luminescence ; Chemistry ; Photoluminescence ; Crystallography ; Molecule ; Inorganic chemistry ; Materials science ; Metal ; Ion ; Organic chemistry Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes ; Metal complexes synthesis and properties
Authors: Varun Shenoy Gangoli | Chris J. Barnett | James McGettrick | Alvin Orbaek White | Andrew R. Barron
Source: C – Journal of Carbon Research (article, 2021-12-23)
Field: Materials Science — Materials Chemistry

Increased Electrical Conductivity of Carbon Nanotube Fibers by Thermal and Voltage Annealing We report the effect of annealing, both electrical and by applied voltage, on the electrical conductivity of fibers spun from carbon nanotubes (CNTs). Commercial CNT fibers were used as part of a larger goal to better understand the factors that go into making a better electrical conductor from CNT fibers. A study of thermal annealing in a vacuum up to 800 °C was performed on smaller fiber sections along with a separate analysis of voltage annealing up to 7 VDC; both exhibited a sweet spot in the process as determined by a combination of a two-point probe measurement with a nanoprobe, resonant Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Scaled-up tests were then performed in order to translate these results into bulk samples inside a tube furnace, with similar results that indicate the potential for an optimized method of achieving a better conductor sample made from CNT fibers. The results also help to determine the surface effects that need to be overcome in order to achieve this. Materials science ; X-ray photoelectron spectroscopy ; Raman spectroscopy ; Carbon nanotube ; Annealing (glass) ; Conductor ; Electrical resistivity and conductivity ; Composite material ; Conductivity ; Thermal conductivity ; Voltage ; Electrical conductor ; Nanotechnology ; Chemical engineering ; Optics ; Electrical engineering ; Chemistry Carbon Nanotubes in Composites ; Graphene research and applications ; Fiber-reinforced polymer composites
Authors: J.C. Rendón-Ángeles | Z. Matamoros-Veloza | José L. Rodríguez-Galicia | Gimyeong Seong | Kazumichi Yanagisawa | Aitana Tamayo | J. Rubio | Lluvia A. Anaya-Chavira
Source: Nanomaterials (article, 2021-02-18)
Field: Chemistry — Inorganic Chemistry

One-Pot Hydrothermal Synthesis of Victoria Green (Ca3Cr2Si3O12) Nanoparticles in Alkaline Fluids and Its Colour Hue Characterisation One-pot hydrothermal preparation of Ca<sub>3</sub>Cr<sub>2</sub>Si<sub>3</sub>O<sub>12</sub> uvarovite nanoparticles under alkaline conditions was investigated for the first time. The experimental parameters selected for the study considered the concentration of the KOH solvent solution (0.01 to 5.0 M), the agitation of the autoclave (50 rpm), and the nominal content of Si<sup>4+</sup> (2.2-3.0 mole). Fine uvarovite particles were synthesised at 200 °C after a 3 h interval in a highly concentrated 5.0 M KOH solution. The crystallisation of single-phase Ca<sub>3</sub>Cr<sub>2</sub>Si<sub>3</sub>O<sub>12</sub> particles proceeded free of by-products via a one-pot process involving a single-step reaction. KOH solutions below 2.5 M and water hindered the crystallisation of the Ca<sub>3</sub>Cr<sub>2</sub>Si<sub>3</sub>O<sub>12</sub> particles. The hydrothermal treatments carried out with stirring (50 rpm) and non-stirring triggered the crystallisation of irregular anhedral particles with average sizes of 8.05 and 12.25 nm, respectively. These particles spontaneously assembled into popcorn-shaped agglomerates with sizes varying from 66 to 156 nm. All the powders prepared by the present method exhibited CIE-L*a*b* values that correspond to the Victoria green colour spectral space and have a high near infrared reflectance property. The particle size and structural crystallinity are factors affecting the Victoria pigment optical properties, such as CIE-L*a*b* values, green tonality, and near-infrared reflectance. Crystallinity ; Hydrothermal circulation ; Agglomerate ; Materials science ; Crystallization ; Mineralogy ; Nanoparticle ; Chemical engineering ; Particle size ; Analytical Chemistry (journal) ; Nuclear chemistry ; Chemistry ; Nanotechnology ; Composite material ; Chromatography Pigment Synthesis and Properties ; Advanced Photocatalysis Techniques ; Luminescence Properties of Advanced Materials
Authors: Robbie P. Joosten | Robert A. Nicholls | Jon Agirre
Source: Current Medicinal Chemistry (article, 2021-09-20)
Field: Chemistry — Organic Chemistry

Towards Consistency in Geometry Restraints for Carbohydrates in the Pyranose form: Modern Dictionary Generators Reviewed Macromolecular restrained refinement is nowadays the most used method for improving the agreement between an atomic structural model and experimental data. Restraint dictionaries, a key tool behind the success of the method, allow fine-tuning geometric properties such as distances and angles between atoms beyond simplistic expectations. Dictionary generators can provide restraint target estimates derived from different sources, from fully theoretical to experimental and any combination in between. Carbohydrates are stereochemically complex biomolecules and, in their pyranose form, have clear conformational preferences. As such, they pose unique problems to dictionary generators and in the course of this study, require special attention from software developers. Functional differences between restraint generators will be discussed, as well as the process of achieving consistent results with different software designs. The study will conclude a set of practical considerations, as well as recommendations for the generation of new restraint dictionaries, using the improved software alternatives discussed. Pyranose ; Consistency (knowledge bases) ; Set (abstract data type) ; Computer science ; Software ; Key (lock) ; Process (computing) ; Algorithm ; Artificial intelligence ; Chemistry ; Programming language ; Stereochemistry Carbohydrate Chemistry and Synthesis ; Glycosylation and Glycoproteins Research ; Enzyme Structure and Function
Authors: Chetan Jagdish Bhongale | Rahul Chaudhari
Source: Engineered Science (article, 2021-01-01)
Field: Materials Science — Polymers and Plastics

All-organic Solution Processed Solar Cells Based on Terephthaladehyde Self-assembled Monolayer Central advance of this work is the formation of high-quality SAM using acetalization reaction that opens up way to control electronic states of electrode/organic interfaces aiding to better device performance with further optimization of solar cells. It is important to note that we can prevent the reaction between ITO and PEDOT:PSS by effectively inserting TPA-SAM in between by acetalization and that increases the life-time of the devices. PEDOT:PSS ; Monolayer ; Organic solar cell ; Materials science ; Electrode ; Nanotechnology ; Self-assembled monolayer ; Optoelectronics ; Chemical engineering ; Polymer ; Chemistry ; Engineering ; Layer (electronics) ; Composite material Conducting polymers and applications ; Organic Electronics and Photovoltaics ; Perovskite Materials and Applications