jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Yanjun Li | Ya-Ting T. Liao
Source: Combustion Science and Technology (article, 2018-04-09)
Field: Materials Science — Materials Chemistry

Thermal analysis and pyrolysis modeling of NOMEX IIIA fabric NOMEX® fabric is widely used in fire safety and military applications for its advantages in thermal and chemical resistance. In this research, thermogravimetric analysis (TGA) and microscale combustion calorimetry (MCC) tests of a NOMEX blend, NOMEX IIIA, were performed in nitrogen flow between 20°C and 800°C. Four heating rates, ranging from 10°C/min to 50°C/min, were used. At all heating rates, mass loss rate data from TGA exhibit peaks at 350–500°C and at 500–650°C. Heat release rate data from MCC also exhibit peaks at the same temperature ranges. This suggests that the sample went through thermal decomposition and yielded combustible gas products at these temperature ranges. As heating rate increased, these peaks shifted to higher temperatures, became wider, and had smaller magnitudes. Based on the test results, three pyrolysis models consisting of multiple consecutive and parallel reaction steps were proposed with different complexities. An Arrhenius expression was used to describe reaction rate as a function of density and temperature of the sample. Pyrolysis kinetic parameters were first theoretically estimated by correlating TGA data with Arrhenius assumptions employing Kissinger, Friedman, and Flynn–Wall–Ozawa methods. The proposed pyrolysis models and associated kinetic parameters were then implemented into a solid combustion code (GPYRO) to simulate the TGA and MCC heating processes. The pyrolysis parameters were fine-tuned to optimize the match between TGA data and modeling results. Combustion heat release rates of gaseous products were estimated using MCC data. All three proposed models were able to reasonably predict TGA and MCC data at all heating rates while the models with higher complexities showed slightly better performance. Pyrolysis ; Materials science ; Thermal ; Thermal analysis ; Composite material ; Chemistry ; Chemical engineering ; Organic chemistry ; Thermodynamics ; Physics ; Engineering Thermal and Kinetic Analysis ; Energetic Materials and Combustion ; Polymer crystallization and properties
Authors: Justyna Czaban‐Jóźwiak | Łukasz Woźniak | Artur Ulikowski | Katarzyna Kwiecińska | Adam A. Rajkiewicz | Karol Grela
Source: Molecules (article, 2018-07-14)
Field: Materials Science — Materials Chemistry

Modification of Polyhedral Oligomeric Silsesquioxanes (POSS) Molecules by Ruthenium Catalyzed Cross Metathesis The scope of ruthenium (Ru)-catalyzed cross metathesis (CM) of allyl-decorated polyhedral oligomeric silsesquioxanes (POSS) was explored. A variety of different commercial and non-commercial ruthenium complexes were tested to determine that the nitro-activated Ru catalyst is optimal for this transformation. The reported transformation was used to prepare selected hybrid steroid-POSS compounds. Ruthenium ; Metathesis ; Catalysis ; Chemistry ; Combinatorial chemistry ; Transformation (genetics) ; Molecule ; Polymer chemistry ; Organic chemistry ; Polymerization ; Polymer Silicone and Siloxane Chemistry ; Synthetic Organic Chemistry Methods ; Organometallic Complex Synthesis and Catalysis
Authors: Roberto D’Amato | Anna Donnadio | Mariolino Carta | Claudio Sangregorio | Riccardo Vivani | Davide Tiana | Marco Taddei | Ferdinando Costantino
Source: ChemRxiv (preprint, 2018-10-15)
Field: Chemistry — Inorganic Chemistry

Water-based Synthesis and Enhanced CO2 Capture Performance of Perfluorinated Cerium-Based Metal-Organic Frameworks with UiO-66 and MIL-140 Topology Reaction of cerium ammonium nitrate and tetrafluoroterephthalic acid in water afforded two new metal-organic frameworks with UiO-66 [F4_UiO-66(Ce)] and MIL-140 [F4_MIL-140A(Ce)] topologies. The two compounds can be obtained in the same experimental conditions, just by varying the amount of acetic acid used as crystallization modulator in the synthesis. Both F4_UiO-66(Ce) and F4_MIL-140A(Ce) feature pores with size < 8 Å, which classifies them as ultramicroporous. Combination of X-ray photoelectron spectroscopy and magnetic susceptibility measurements revealed that both compounds contain a small amount of Ce(III), which is preferentially accumulated near the surface of the crystallites. The CO2 sorption properties of F4_UiO-66(Ce) and F4_MIL-140A(Ce) were investigated, finding that they perform better than their Zr-based analogues. F4_MIL-140A(Ce) displays an unusual S-shaped isotherm with steep uptake increase at pressure < 0.2 bar at 298 K. This makes F4_MIL-140A(Ce) exceptionally selective for CO2 over N2: the calculated selectivity, according to the ideal adsorbed solution theory for a 0.15:0.85 mixture at 1 bar and 293 K, is higher than 1900, amongst the highest ever reported for metal-organic frameworks. The calculated isosteric heat of CO2 adsorption is in the range of 38-40 kJ mol-1, indicating a strong physisorptive character. Cerium ; Metal-organic framework ; Topology (electrical circuits) ; Materials science ; Environmental science ; Chemistry ; Organic chemistry ; Engineering ; Electrical engineering ; Metallurgy Metal-Organic Frameworks: Synthesis and Applications ; Carbon Dioxide Capture Technologies ; Catalytic Processes in Materials Science
Authors: Mohamed E. Assal | Mohammed Rafi Shaik | Mufsir Kuniyil | Mujeeb Khan | Abdulrahman Al–Warthan | Mohammed Rafiq H. Siddiqui | Syed Farooq Adil
Source: Metals (article, 2018-06-19)
Field: Chemistry — Organic Chemistry

Ag2O Nanoparticles-Doped Manganese Immobilized on Graphene Nanocomposites for Aerial Oxidation of Secondary Alcohols Ag2O nanoparticles-doped MnO2 decorated on different percentages of highly reduced graphene oxide (HRG) nanocomposites, i.e., (X%)HRG/MnO2–(1%)Ag2O (where X = 0–7), were fabricated through straight-forward precipitation procedure, and 400 °C calcination, while upon calcination at 300 °C and 500 °C temperatures, it yielded MnCO3 and manganic trioxide (Mn2O3) composites, i.e., [(X%)HRG/MnCO3–(1%)Ag2O] and [(X%)HRG/Mn2O3–(1%)Ag2O], respectively. These nanocomposites have been found to be efficient and very effective heterogeneous catalysts for selective oxidation of secondary alcohols into their respective ketones using O2 as a sole oxidant without adding surfactants or nitrogenous bases. Moreover, a comparative catalytic study was carried out to investigate the catalytic efficiency of the synthesized nanocomposites for the aerobic oxidation of 1-phenylethanol to acetophenone as a substrate reaction. Effects of several factors were systematically studied. The as-prepared nanocomposites were characterized by TGA, XRD, SEM, EDX, HRTEM, BET, Raman, and FTIR. The catalyst with structure (5%)HRG/MnO2–(1%)Ag2O showed outstanding specific activity (16.0 mmol/g·h) with complete conversion of 1-phenylethanol and &gt;99% acetophenone selectivity within short period (25 min). It is found that the effectiveness of the catalyst has been greatly improved after using graphene support. A broad range of alcohols have selectively transformed to desired products with 100% convertibility and no over-oxidation products have been detected. The recycling test of (5%)HRG/MnO2–(1%)Ag2O catalyst for oxidation of 1-phenylethanol suggested no obvious decrease in its performance and selectivity even after five subsequent runs. Catalysis ; Acetophenone ; Calcination ; Alcohol oxidation ; Nanocomposite ; Graphene ; Selectivity ; Materials science ; Nanoparticle ; Catalytic oxidation ; Inorganic chemistry ; Chemical engineering ; Nuclear chemistry ; Chemistry ; Organic chemistry ; Nanotechnology Oxidative Organic Chemistry Reactions ; Nanomaterials for catalytic reactions ; Mesoporous Materials and Catalysis
Authors: Paula M. Uberman | Sandra E. Martı́n
Source: Current Organic Chemistry (article, 2018-10-29)
Field: Chemistry — Organic Chemistry

Palladium-Catalyzed Arsination Reactions and their Applications on the Synthesis of Arsine Ligands In the synthesis of new ligands for metal-catalyzed reactions, arsines are attracting particular attention, because arsine ligands have been shown to be better ligands than structurally related phosphines in several catalyzed reactions. However, the synthesis and applications of arsine ligands is not widely extended in the literature. One of the main barriers to develop new arsine ligands is found in the synthetic methodologies to obtain arsine compounds. Therefore, to expand the applications of arsine ligands it is necessary to develop new synthetic strategies. To improve the classic arsination reactions metalcatalyzed C-As bond formation reactions appears to be a promising approach. This article highlights the palladium-catalyzed arsination reactions, providing the synthetic approaches used to obtain arsines. In addition, the few described examples of other metalcatalyzed arsination reactions are included. The synthesis of structurally diverse arsine ligands by catalyzed arsination reactions is summarized, as well as the most relevant issues of their applications in homogeneous catalysis. Keywords: Palladium, Pd-catalyzed arsination, catalyzed arsination, arsine ligands, aryl arsines, coupling reactions, heck. Arsine ; Chemistry ; Palladium ; Catalysis ; Combinatorial chemistry ; Aryl ; Homogeneous catalysis ; Homogeneous ; Organic chemistry ; Phosphine Catalytic Cross-Coupling Reactions ; Catalytic C–H Functionalization Methods ; Chemical Synthesis and Analysis
Authors: Shreya Nandi | Dimitri Blanck | Thomas Carlier | Marie‐Hélène Chambrier | Anne-Sophie Mamède | Martine Trentesaux | Pardis Simon | Nicolas Nuns | Pascal Roussel | Anthony Ferri | Jean‐François Paul | Élise Berrier
Source: Surface and Interface Analysis (article, 2018-05-17)
Field: Materials Science — Materials Chemistry

LaFeO <sub>3</sub> thin films as relevant models for the surface investigation of 3‐way catalysts Lanthanum orthoferrite, a highly potential 3‐way catalyst, shaped as a polycrystalline thin film has been comprehensively analysed by combining bulk and surface characterization techniques. The possibility to accomplish unprecedented surface information has been presented, thanks to the combined use of LEIS, XPS, and ToF‐SIMS. The structural, morphological, and surface properties at nanometric scale make such thin films indistinguishable from powdered solids. Thus, the relevance of using such model materials for advanced surface investigations of LaFeO 3± δ ‐based 3‐way catalysts has been demonstrated. Materials science ; Crystallite ; Thin film ; Characterization (materials science) ; Catalysis ; Orthoferrite ; X-ray photoelectron spectroscopy ; Lanthanum ; Nanotechnology ; Chemical engineering ; Surface (topology) ; Chemistry ; Inorganic chemistry ; Metallurgy ; Organic chemistry ; Physics ; Engineering Electronic and Structural Properties of Oxides ; Minerals Flotation and Separation Techniques ; ZnO doping and properties
Authors: Luca Valentini | Silvia Bittolo Bon | Nicola M. Pugno
Source: Preprints.org (preprint, 2018-06-20)
Field: Materials Science — Biomaterials

Combining Living Microorganisms with Regenerated Silk Provides Nanofibril Based Thin Films with heat Responsive Wrinkled States for Smart Food Packaging Regenerated silk (RS) is a protein-based &amp;ldquo;biopolymer&amp;rdquo; that enables the design of new materials; here we sought to &amp;ldquo;bionic&amp;rdquo; the process of regenerated silk production by fermentation assisted method. Based on yeast&amp;rsquo;s fermentation, here we produced a living hybrid composite made of regenerated silk nanofibrils and a single-cell fungi, the Saccharomyces Cerevisiae yeast extract, by fermentation of such microorganisms at room temperature in the dissolution bath of silkworm silk fibers. The fermentation-based processing enhances the beta-sheet content of the RS, corresponding to a reduction in water permeability and CO2 diffusion through RS/yeast thin films enabling the fabrication of mechanically robust film that enhances the food storage durability. Finally a transfer print method, which consists of transferring RS and RS/yeast film layers onto self-adherent paraffin substrate, was used for the realization of heat &amp;ndash; responsive wrinkles by exploiting the high thermal expansion of the paraffin substrate that regulates the applied strain, resulting in a switchable coating morphology from the wrinkle-free state to a wrinkled state if the food temperature overcomes a designed threshold. We envision that such efficient and smart coatings can be applied for the realization of smart packaging that through such temperature sensing mechanism can be used to control the food storage conditions. SILK ; Biopolymer ; Materials science ; Yeast ; Food packaging ; Substrate (aquarium) ; Coating ; Fermentation ; Nanotechnology ; Composite material ; Food science ; Chemistry ; Polymer ; Biology Silk-based biomaterials and applications ; Insect and Arachnid Ecology and Behavior ; Advanced Materials and Mechanics
Authors: Andrei Rotaru | Finlay D. Morrison
Source: Ceramics International (article, 2018-09-20)
Field: Materials Science — Materials Chemistry

Structural, electrical and relaxor properties of Sc-In solid solution in tetragonal tungsten bronze ceramics Materials science ; Tungsten ; Tetragonal crystal system ; Grain boundary ; Dielectric ; Electrical resistivity and conductivity ; Bronze ; Dielectric spectroscopy ; Ceramic ; Pellets ; Extrapolation ; Analytical Chemistry (journal) ; Solid solution ; Condensed matter physics ; Microstructure ; Composite material ; Crystallography ; Metallurgy ; Crystal structure ; Physical chemistry Ferroelectric and Piezoelectric Materials ; Microwave Dielectric Ceramics Synthesis ; Multiferroics and related materials
Authors: P. Gangopadhyay
Source: NanoWorld Journal (article, 2018-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Metallic Alloy Nanoparticles and Metal-Semiconductor Nanomaterials Parthasarathi Gangopadhyay While bridging the gap between the atomic structures and bulk matters, nanomaterials are of great interests for fundamental understanding as well as for different application perspectives. Nanomaterials ; Alloy ; Materials science ; Nanoparticle ; Metal ; Nanotechnology ; Semiconductor ; Metallurgy ; Optoelectronics Gold and Silver Nanoparticles Synthesis and Applications ; nanoparticles nucleation surface interactions ; Copper-based nanomaterials and applications
Authors: Valentina Milašinović | Krešimir Molčanov
Source: Croatica Chemica Acta (article, 2018-01-01)
Field: Chemistry — Organic Chemistry

Alkali Salts of Nitranilic and Cyanochloranilic Acids Series of novel alkali salts of nitranilic acid (3,6-dinitro-2,5-dihydroxyquinone) and cyanochloranilic acid (3-cyano-6-chloro-2,5dihydroxyquinone), and also of neutral cyanochloranilic acid dihydrate, were prepared and their structures were studied. The nitranilate dianion revealed a considerable conformational flexibility of nitro groups. Steric and inductive effects exerted by different substituents (nitro, cyano and chloro) and their influence on molecular geometry and crystal packing are discussed. Alkali metal ; Chemistry ; Organic chemistry Structural and Chemical Analysis of Organic and Inorganic Compounds ; Crystal structures of chemical compounds ; Phenothiazines and Benzothiazines Synthesis and Activities
Authors: Jiaxing Sun | Xiao Zhang | Long Bai | Zhiguo Li | Jia Zhao | Jiyou Gu
Source: Materials (article, 2018-12-06)
Field: Materials Science — Biomaterials

Effect of Shell Growth on the Morphology of Polyvinyl Acetate/Polystyrene Inverted Core-Shell Latex Fabricated by Acrylonitrile Grafting A novel strategy for fabricating inverted core-shell structured latex particles was implemented to investigate the morphology and properties of polyvinyl acetate (PVAc)-based latex. In this study, active grafting points were synthesized onto the surface of PVAc latex cores via grafting acrylonitrile (AN) to obtain a controllable coating growth of the shell monomer, styrene (St). The effect of shell growth on the morphological evolvement was explored by tuning the time of shell monomer polymerization. Unique particle morphologies, transferring from "hawthorn" type, over "peeled pomegranate" type, to final "strawberry-like" type, were observed and verified by electron microscopy. The morphological structure of latex particles exerted a significant effect on the particle size, phase structure, and mechanical properties of the obtained emulsions. The water-resistance of PVAc-based latex was also evaluated by the water absorption of latex films. More importantly, the experimental results provided a reasonable support for the controlled growth of St monomer, that is, the self-nucleation of dispersive St monomer can be transformed to in-situ coating growth on the PVAc core surface depending on the AN-active grafting points. This fabricating approach provides a reference for dynamical design and control of the latex particle morphology. Acrylonitrile ; Polystyrene ; Materials science ; Grafting ; Polyvinyl acetate ; Shell (structure) ; Morphology (biology) ; Polymer chemistry ; Polyvinyl alcohol ; Core (optical fiber) ; Composite material ; Chemical engineering ; Polymer science ; Copolymer ; Polymer biodegradable polymer synthesis and properties ; Material Properties and Processing ; Photopolymerization techniques and applications
Authors: Stefan Krause | Mads Koerstz | Riikka Arppe | Tero Soukka | Tom Vosch
Source: Methods and Applications in Fluorescence (article, 2018-09-05)
Field: Materials Science — Materials Chemistry

NIR induced modulation of the red emission from erbium ions for selective lanthanide imaging Upon direct excitation with green light (522 nm), Er<sup>3+</sup> ion doped nanoparticles feature a number of radiative and non-radiative decay pathways, leading to distinct and sharp emission lines in the visible and near-infrared (NIR) range. Here we apply, in addition to continuous 522 nm irradiation, a modulated NIR irradiation (1143 nm) to actively control and modulate the red emission intensity (around 650 nm). The modulation of red Er<sup>3+</sup> ion emission at a chosen frequency allows us to reconstruct fluorescence images from the Fourier transform amplitude at this particular frequency. Since only the emission from the Er<sup>3+</sup> ion is modulated, it allows to selectively recover the lanthanide specific signal, removing any non-modulated auto-fluorescence or background emission resulting from the continuous 522 nm excitation. The modulated emission of specific lanthanides can open up new detection opportunities for selective signal recovery. Lanthanide ; Fluorescence ; Erbium ; Ion ; Excitation ; Materials science ; Irradiation ; Photon upconversion ; Modulation (music) ; Infrared ; Radiative transfer ; Emission spectrum ; Near-infrared spectroscopy ; Luminescence ; SIGNAL (programming language) ; Analytical Chemistry (journal) ; Chemistry ; Optoelectronics ; Optics ; Doping ; Spectral line ; Physics Luminescence Properties of Advanced Materials ; Luminescence and Fluorescent Materials ; Lanthanide and Transition Metal Complexes
Authors: D. Martoccia | Holger Lutz | Yvan Cohen | Thomas Jerphagnon | Urban Jenelten
Source: CHIMIA International Journal for Chemistry (article, 2018-03-30)
Field: Chemistry — Analytical Chemistry

FT-NIR: A Tool for Process Monitoring and More With ever-increasing pressure to optimize product quality, to reduce cost and to safely increase production output from existing assets, all combined with regular changes in terms of feedstock and operational targets, process monitoring with traditional instruments reaches its limits. One promising answer to these challenges is in-line, real time process analysis with spectroscopic instruments, and above all Fourier-Transform Near Infrared spectroscopy (FT-NIR). Its potential to afford decreased batch cycle times, higher yields, reduced rework and minimized batch variance is presented and application examples in the field of fine chemicals are given. We demonstrate that FT-NIR can be an efficient tool for improved process monitoring and optimization, effective process design and advanced process control. Rework ; Process engineering ; Process (computing) ; Process analytical technology ; Computer science ; Raw material ; Near-infrared spectroscopy ; Work in process ; Process control ; Production (economics) ; Environmental science ; Engineering ; Chemistry ; Operations management ; Embedded system Spectroscopy and Chemometric Analyses ; Fault Detection and Control Systems ; Spectroscopy Techniques in Biomedical and Chemical Research
Authors: Laura M. Otter | Oluwatoosin B. A. Agbaje | Matt R. Kilburn | Christoph Lenz | Hadrien Henry | Patrick Trimby | P. Höppe | Dorrit E. Jacob
Source:  (article, 2018-11-09)
Field: Materials Science — Biomaterials

Architecture, Growth Dynamics and Biomineralization of Pulsed Sr-Labelled <i>Katelysia rhytiphora</i> (Mollusca, Bivalvia) Abstract. We use pulsed Sr-labelling experiments to visualize growth of aragonitic Katelysia rhytiphora (Mollusca, Bivalvia) shells. The outer compound composite prismatic structure is organized into three orders of prisms, and the inner crossed acicular structure consists of intersecting lamellae. Electron Backscatter Diffraction (EBSD) reveals substantial twinning of the aragonite crystals (&gt; 46 %) and an overall reduced and strategically oriented anisotropy of the Young’s modulus in the whole shell compared to that of monolithic aragonite. All structural orders in both layers are enveloped by an organic sheath and the smallest mineralized units are nanogranules. Total organic contents are 2.2 (outer) and 1.4 wt. % (inner layer) and are, thus, intermediate between those of nacreous and crossed-lamellar shells. Prisms in the outer structure can be correlated to yearly, daily and sub-daily growth rates. Average daily growth rates at the ventral margin for the outer structure are 17 % higher than for the inner crossed acicular structure. The calcification front runs evenly across all structures and architectural orders independently of the current growth rate. Sharply defined transitions from labelled to unlabelled areas in the shell indicate that physiological processes driving calcification have no lag. This suggests that the extrapallial fluid cannot be very voluminous. Narrow increments of varying Sr content within labelled shell, despite constant Sr concentrations in seawater, suggest cyclic metabolic activity during calcification. Micro-Raman spectroscopy maps validate a low impact of high Sr-conditions on the aragonite crystal structure. Identical Sr-enrichment factors for labelled and ambient conditions support models of ion transport via a passive selective pathway to the mantle epithelium followed by calcification via amorphous calcium carbonate. Aragonite ; Pinctada fucata ; Calcite ; Biomineralization ; Bivalvia ; Shell (structure) ; Mollusca ; Electron backscatter diffraction ; Calcification ; Mineralogy ; Acicular ; Materials science ; Crystallography ; Chemistry ; Geology ; Biophysics ; Biology ; Composite material ; Microstructure ; Paleontology Calcium Carbonate Crystallization and Inhibition ; Paleontology and Stratigraphy of Fossils ; Marine Bivalve and Aquaculture Studies