jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Zhao Li | Jianfu Ding | J. Lefebvre | Patrick R. L. Malenfant
Source: ACS Omega (article, 2018-03-21)
Field: Materials Science — Materials Chemistry

Dopant-Modulated Conjugated Polymer Enrichment of Semiconducting SWCNTs Conjugated polymer extraction (CPE) is a low-cost, scalable process that can enrich single-walled carbon nanotube (SWCNT) materials in organic media. For other separation methods in aqueous phases, redox chemistry and/or pH control dramatically affect the sorting process of the SWCNTs. We have previously determined that the CPE process can be fine-tuned by adjusting the pH on the tube surface. Here, we systematically studied the effect of redox chemistry on the CPE process by adding organic p-/n-dopants. At a very strong p-/n-doping level, static repulsions dominated the interactions between the tubes and the CPE lost selectivity. When the doping level changed from a medium p-doping to a neutral state, the yield of CPE increased and the selectivity was compromised. We also observed chiral selectivity when a weak p-dopant was used. A photoluminescence excitation mapping under different titration conditions provided more insight into the doping level of the tubes relative to their diameters, chiralities, and redox potentials. We proposed a mechanism for the CPE process. The semiconducting and metallic tubes are separated because of their different solubilities, which are determined by the bundling energy between the tubes and are related to their doping level in polymer solutions. Dopant ; Doping ; Conjugated system ; Selectivity ; Polymer ; Carbon nanotube ; Materials science ; Redox ; Photoluminescence ; Titration ; Chemical engineering ; Photochemistry ; Nanotechnology ; Inorganic chemistry ; Organic chemistry ; Chemistry ; Catalysis ; Optoelectronics ; Composite material Carbon Nanotubes in Composites ; Nanopore and Nanochannel Transport Studies ; Conducting polymers and applications
Authors: Xi Chen | Yao‐Wen Wu
Source: Angewandte Chemie (article, 2018-04-11)
Field: Materials Science — Materials Chemistry

Tunable and Photoswitchable Chemically Induced Dimerization for Chemo‐optogenetic Control of Protein and Organelle Positioning Abstract The spatiotemporal dynamics of proteins and organelles play an important role in controlling diverse cellular processes. Optogenetic tools using photosensitive proteins and chemically induced dimerization (CID), which allow control of protein dimerization, have been used to elucidate the dynamics of biological systems and to dissect the complicated biological regulatory networks. However, the inherent limitations of current optogenetic and CID systems remain a significant challenge for the fine‐tuning of cellular activity at precise times and locations. Herein, we present a novel chemo‐optogenetic approach, photoswitchable chemically induced dimerization (psCID), for controlling cellular function by using blue light in a rapid and reversible manner. Moreover, psCID is tunable; that is, the dimerization and dedimerization degrees can be fine‐tuned by applying different doses of illumination. Using this approach, we control the localization of proteins and positioning of organelles in live cells with high spatial (μm) and temporal (ms) precision. Optogenetics ; Organelle ; Biophysics ; Chemistry ; Synthetic biology ; Nanotechnology ; Materials science ; Biology ; Computational biology ; Neuroscience ; Biochemistry Photochromic and Fluorescence Chemistry ; Photoreceptor and optogenetics research ; Light effects on plants
Authors: J.B. Baruah
Source: Journal of Chemical Sciences (article, 2018-05-01)
Field: Chemistry — Inorganic Chemistry

Predominantly ligand guided non-covalently linked assemblies of inorganic complexes and guest inclusions Supramolecular chemistry ; Covalent bond ; Template ; Ligand (biochemistry) ; Non-covalent interactions ; Chemistry ; Molecule ; Molecular recognition ; Nanotechnology ; Hydrogen bond ; Self-assembly ; Materials science ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Crystallography and molecular interactions ; Supramolecular Chemistry and Complexes
Authors: Santanu Malakar | S. V. Shree Sowndarya | Raghavan B. Sunoj
Source: Organic & Biomolecular Chemistry (article, 2018-01-01)
Field: Chemistry — Spectroscopy

A quantification scheme for non-covalent interactions in the enantio-controlling transition states in asymmetric catalysis The origin of enantioselectivity in asymmetric catalysis is attributed to the energy difference between lower and higher energy diastereomeric transition states, which are respectively responsible for the formation of major and minor enantiomers. Although the increase in the number of transition state models emphasizes the role of weak non-covalent interactions in asymmetric induction, the strength of such interactions is seldom quantified. Through this article, we propose a simple and effective method of quantifying the total non-covalent interaction in stereocontrolling transition states belonging to a group of three representative asymmetric catalytic reactions involving chiral phosphoric acids. Our method relies on rational partitioning of a given transition state into two (or three) sub-units, such that the complex network of intramolecular interactions can be ameliorated to a set of intermolecular interactions between two sub-units. The computed strength of interaction obtained using the counterpoise (CP) method on suitably partitioned transition states provides improved estimates of non-covalent interactions, which are also devoid of basis set superposition error (BSSE). It has been noted that catalysts decorated with larger aromatic arms provide cumulative non-covalent interactions (C-Hπ, N-Hπ and ππ) to the tune of 10 to 15 kcal mol-1. Fine-tuning of the magnitude and nature of these interactions can provide valuable avenues in the design of asymmetric catalysts. Chemistry ; Catalysis ; Transition state ; Covalent bond ; Scheme (mathematics) ; Transition (genetics) ; Computational chemistry ; Organic chemistry Molecular spectroscopy and chirality ; Advanced Chemical Physics Studies ; Surface Chemistry and Catalysis
Authors: Sankaranarayanan Ayyakudi Ravichandran | Jordan Krist | D. J. H. Edwards | Saied Delagah | John Pellegrino
Source: Separation and Purification Technology (article, 2018-10-05)
Field: Materials Science — Biomaterials

Measuring sparingly-soluble, aqueous salt crystallization kinetics using CSTRs-in-series: Methodology development and CaCO3 studies Crystallization ; Supersaturation ; Mixing (physics) ; Residence time (fluid dynamics) ; Continuous stirred-tank reactor ; Turbidity ; Chemistry ; Volume (thermodynamics) ; Chemical engineering ; Thermodynamics ; Materials science ; Physical chemistry Calcium Carbonate Crystallization and Inhibition ; Chemical and Physical Properties in Aqueous Solutions ; Membrane-based Ion Separation Techniques
Authors: Matheus P. Lima | A. Fazzio | Antônio J. R. da Silva
Source: IEEE Electron Device Letters (article, 2018-06-18)
Field: Materials Science — Materials Chemistry

Silicene-Based FET for Logical Technology 2-D materials are considered to have great potential to integrate future generations of nanoelectronic devices aiming to outperform the limitations that will eventually reach the conventional silicon technology. In this letter, a field-effect transistor composed by half-hydrogenated-silicene (HHS) connected to pristine silicene regions is theoretically investigated. Using ab-initio ballistic transport simulations based on DFT, it is shown that this device has an extremely high I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> /I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OFF</sub> ratio, for very small bias voltages and for channel lengths smaller than 10 nm. In particular, an expression for I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> = I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OFF</sub> exp {[3.35Å <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> ]w} is obtained, where w is the channel length. Finally, we demonstrated that the peculiar electronic structure of the HHS allows a fine-tuning of the charge transport mechanism resulting in ultra-low values for the subthreshold slope close to 24.5 meV /dec, which overcomes the inferior limit of 60 meV /dec claimed for conventional devices. Silicene ; Physics ; Topology (electrical circuits) ; Silicon ; Electrical engineering ; Optoelectronics ; Engineering Graphene research and applications ; Quantum and electron transport phenomena ; Molecular Junctions and Nanostructures
Authors: Wen‐Bo Pei | Zhi-Yu Jing | Li‐Te Ren | Yabo Wang | Jiansheng Wu | Ling Huang | Raymond Lau | Wei Huang
Source: Inorganic Chemistry (article, 2018-08-17)
Field: Materials Science — Materials Chemistry

Nearly Pure Red Color Upconversion Luminescence of Ln-Doped Sc<sub>2</sub>O<sub>3</sub> with Unexpected RE-MOFs Molecular Alloys as Precursor Unexpected Sc/Ln codoped rare earth metal-organic frameworks (RE-MOFs) molecular alloys (MAs) based on an oxalic acid ligands were obtained. Calcination of the RE-MOFs MAs gave the corresponding codoped rare earth oxides a strong and nearly pure red color upconversion luminescence. It allows the resulting lanthanide ion (Ln<sup>3+</sup>) doped upconversion materials a wide range of applications from optical communications to disease diagnosis. Moreover, the pyrolysis RE-MOFs MAs precursor has demonstrated to be an effective preparation method for a uniform Ln-doped Sc<sub>2</sub>O<sub>3</sub> system. Lanthanide ; Photon upconversion ; Chemistry ; Luminescence ; Oxalic acid ; Calcination ; Doping ; Pyrolysis ; Rare earth ; Inorganic chemistry ; Ion ; Optoelectronics ; Mineralogy ; Catalysis ; Materials science ; Organic chemistry Luminescence Properties of Advanced Materials ; Lanthanide and Transition Metal Complexes ; Metal-Organic Frameworks: Synthesis and Applications
Authors: Katsuya Shimizu | Daichi Kitagawa | Seiya Kobatake
Source: Dyes and Pigments (article, 2018-09-26)
Field: Materials Science — Materials Chemistry

Solid emission color tuning of polymers consisting of BODIPY and styrene in various ratios Intermolecular force ; Polymer ; BODIPY ; Quantum yield ; Copolymer ; Fluorophore ; Fluorescence ; Styrene ; Materials science ; Monomer ; Photochemistry ; Tetrahydrofuran ; Polymer chemistry ; Chemistry ; Molecule ; Organic chemistry ; Optics Luminescence and Fluorescent Materials ; Molecular Sensors and Ion Detection ; Organic Light-Emitting Diodes Research
Authors: Mateus Batista Simões | Sajjad Ullah | Chanchal Hazra | Michel Wong Chi Man | Sidney J. L. Ribeiro | Ubirajara Pereira Rodrigues Filho
Source: Journal of Luminescence (article, 2018-04-20)
Field: Materials Science — Materials Chemistry

Eco-friendly polydimethylsiloxane-based self-supporting film containing europium-polyoxometalate: A flexible luminescent material for white light generation Polyoxometalate ; Europium ; Luminescence ; Polydimethylsiloxane ; Materials science ; Lanthanide ; Tungstate ; Light-emitting diode ; Optoelectronics ; Nanotechnology ; Hybrid material ; Ion ; Chemistry ; Organic chemistry Polyoxometalates: Synthesis and Applications ; Lanthanide and Transition Metal Complexes ; Radioactive element chemistry and processing
Authors: Chun‐Yen Liu | Yan‐Song Zhang | Ching-Pin Kao | Jirun Liu
Source: eXPRESS Polymer Letters (article, 2018-01-01)
Field: Materials Science — Surfaces, Coatings and Films

Fabrication of silver nanowires via a β-cyclodextrin-derived soft template Supramolecular -cyclodextrin (-CD) was used as a soft template for the fabrication of long silver nanowires. A novel design using self-assembled -CD for the reduction of silver ions was studied. The concentrations of iron chloride, silver nitrate, and the template were controlling factors for the growth of the silver nanowires. Iron chloride was used to accelerate and facilitate the formation of the silver nanowires and inhibit oxidative etching. However, an excessive concentration of Fe +3 resulted in etching of the silver nanostructures. Furthermore, the silver concentration was another controlling factor. The length of the silver nanowires increased as the concentration of silver cations increased. Nevertheless, an excess concentration of silver cations formed various silver crystalline structures. In this study, the optimal ratio between iron chloride and silver nitrate was determined to be 1:13.3. A maximum length of 20 m was achieved using a concentration of 0.23 M for the soft template. Moreover, the junction of two growing silver nanowires was observed, forming a long fused nanowire, and some significant boundaries were observed. The observed results were further confirmed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. X-ray diffraction (XRD) and energy dispersive spectrometer (EDS) analyses were used to indicate the presence of silver and the formation of crystalline materials. Silver nitrate ; Scanning electron microscope ; Materials science ; Nanowire ; Transmission electron microscopy ; Silver chloride ; Etching (microfabrication) ; Chemical engineering ; Fabrication ; Chloride ; Nanomaterials ; Nanotechnology ; Powder diffraction ; Silver nanoparticle ; Silver Nano ; Inorganic chemistry ; Crystallography ; Nano- ; Chemistry ; Composite material ; Metallurgy ; Nanoparticle ; Electrode ; Layer (electronics) ; Physical chemistry Polymer Surface Interaction Studies ; Innovative Microfluidic and Catalytic Techniques Innovation ; Advanced biosensing and bioanalysis techniques
Authors: Giuseppe Romanazzi | Piero Mastrorilli | Mario Latronico | Matilda Mali | Angelo Nacci | Maria Michela Dell’Anna
Source: Open Chemistry (article, 2018-01-01)
Field: Chemistry — Organic Chemistry

Catalytic activities of heterogeneous catalysts obtained by copolymerization of metal-containing 2-(acetoacetoxy)ethyl methacrylate Abstract Among the synthetic strategies commonly used for supporting a metal complex onto an organic polymer in order to obtain an heterogenous catalyst, a valid choice is to synthesize a metal containing monomer (MCM), which can subsequently be subjected to polymerization with suitable comonomers and crosslinkers, achieving a supported transition metal catalyst as a metal-containing polymer (MCP). In this context, during the last two decades, we explored the use of 2-(acetoacetoxy)ethyl methacrylate (HAAEMA) as a ligand to prepare several MCMs for the relevant MCPs. In this review we summarize and discuss our developments in the studies of the catalytic activity of these “hybrid” catalysts. These catalysts have demonstrated high efficiency and/or excellent selectivity in several kinds of chemical reactions and very often they could be recovered and reused in multiple cycles maintaining their activity and selectivity without suffering from appreciable metal leaching. Catalysis ; Selectivity ; Methacrylate ; Copolymer ; Polymer ; Monomer ; Polymerization ; Metal ; Materials science ; Transition metal ; Leaching (pedology) ; Context (archaeology) ; Polymer chemistry ; Ligand (biochemistry) ; Chemistry ; Organic chemistry ; Combinatorial chemistry Chemical Synthesis and Reactions ; Catalytic Cross-Coupling Reactions ; Synthetic Organic Chemistry Methods
Authors: Jonathan Cisterna | Catherine Araneda | Pilar Narea | Alejandro Cárdenas | Jaime Llanos | Iván Brito
Source: Molecules (article, 2018-10-14)
Field: Chemistry — Inorganic Chemistry

The Positional Isomeric Effect on the Structural Diversity of Cd(II) Coordination Polymers, Using Flexible Positional Isomeric Ligands Containing Pyridyl, Triazole, and Carboxylate Fragments To systematically investigate the influence of the positional isomeric effect on the structures of polymer complexes, we prepared two new polymers containing the two positional isomers ethyl 5-methyl-1-(pyridin-3-yl)-1<i>H</i>-1,2,3-triazole-3-carboxylate (<b>L1</b>) and ethyl-5-methyl-1-(pyridin-3-yl)-1<i>H</i>-1,2,3-triazole-4-carboxylate (<b>L2</b>), as well as Cd(II) ions. The structures of the metal⁻organic frameworks were determined by a single crystal XRD analysis. The compound [Cd(L1)₂·4H₂O] (<b>1</b>), is a hydrogen bond-induced coordination polymer, whereas the compound [Cd(L2)₄·5H₂O]<sub>n</sub> (<b>2</b>) is a three-dimensional (3-D) coordination polymer. Their structures and properties are tuned by the variable N-donor positions of the ligand isomers. This work indicates that the isomeric effect of the ligand isomers plays an important role in the construction of the Cd(II) complexes. In addition, the thermal and luminescent properties are reported in detail. Carboxylate ; Chemistry ; Stereochemistry ; Triazole ; 1,2,4-Triazole ; Coordination complex ; Structural isomer ; Combinatorial chemistry ; Medicinal chemistry ; Organic chemistry ; Metal Metal-Organic Frameworks: Synthesis and Applications ; Magnetism in coordination complexes ; Metal complexes synthesis and properties
Authors: Yi Han | Ruoshi Li | Christian Brückner | Timothy M. Vadas
Source: C – Journal of Carbon Research (article, 2018-07-09)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Controlling the Surface Oxygen Groups of Polyacrylonitrile-Based Carbon Nanofiber Membranes While Limiting Fiber Degradation Enhancing the performance of nanofibrous carbons requires the specific chemical functionalization of the surface, while limiting material degradation or causing other detrimental changes in the surface area and pore structures. We compare traditional oxidation protocols using HNO3, HNO3/H2SO4, and KMnO4 with the much less used oxidants RuO4 and OsO4, in tandem with secondary oxidants (such as KMnO4 or Oxone®), for their ability to form carboxylic acids on the surface of polyacrylonitrile-based activated carbon nanofiber membrane (ACNF) materials. While the traditional methods increased the carboxylic acid contents, they also destroyed the macrostructure of the ACNF, concomitant with the loss of up to 17 wt.% of the material. RuO4-mediated oxidations proved also to be too harsh. On the contrary, some of the OsO4-based protocols were characterized by very high mass yields; significant increase in carboxylic acid functionalization (6.3 µmol/mg) compared with the unmodified ACNF (1.7 µmol/mg), but with no concomitant loss of macrostructure, as measured by the retention of the Brunauer-Emmett-Teller (BET) surface area; and average pore width. While there was some reduction in micropore volume, the microporosity of the material remained high. The temperature-programmed desorption mass spectrometry (up to 1000 °C) indicated the presence of both single and adjacent carboxylic acid groups. We thus identified mild and highly effective reaction conditions for the functionalization of carbon nanomaterials without undue degradation of their physical properties. Polyacrylonitrile ; Surface modification ; Chemistry ; Specific surface area ; Desorption ; Carbon nanofiber ; Nanofiber ; Carboxylic acid ; Chemical engineering ; Carbon fibers ; BET theory ; Degradation (telecommunications) ; Polymer chemistry ; Materials science ; Organic chemistry ; Nanotechnology ; Adsorption ; Polymer ; Composite number ; Catalysis ; Composite material Supercapacitor Materials and Fabrication ; Graphene research and applications ; Fuel Cells and Related Materials
Authors: Min Young Song | Hae Won Ryu | Sang‐Chul Jung | JiHyeon Song | Byung-Joo Kim | Young‐Kwon Park
Source: Catalysts (article, 2018-09-10)
Field: Materials Science — Materials Chemistry

A Hybrid Reactor System Comprised of Non-Thermal Plasma and Mn/Natural Zeolite for the Removal of Acetaldehyde from Food Waste The degradation of low concentrations of acetaldehyde while using a non-thermal plasma (NTP)/catalyst hybrid reactor system was investigated while using humidified air at ambient temperature. A series of highly active manganese-impregnated natural zeolite (Mn/NZ) catalysts were synthesized by the incipient wetness method using sonication. The Mn/NZ catalysts were analyzed by Brunauer-Emmett-Teller surface area measurements and X-ray photoelectron spectroscopy. The Mn/NZ catalyst located at the downstream of a dc corona was used for the decomposition of ozone and acetaldehyde. The decomposition efficiency of ozone and acetaldehyde was increased significantly using the Mn/NZ catalyst with NTP. Among the various types of Mn/NZ catalysts with different Mn contents, the 10 wt.% Mn/NZ catalyst under the NTP resulted the highest ozone and acetaldehyde removal efficiency, almost 100% within 5 min. Moreover, this high efficiency was maintained for 15 h. The main reason for the high catalytic activity and stability was attributed to the high dispersion of Mn on the NZ made by the appropriate impregnation method using sonication. This system is expected to be efficient to decompose a wide range of volatile organic compounds with low concentrations. Acetaldehyde ; Catalysis ; Zeolite ; Ozone ; Chemistry ; Decomposition ; Chemical engineering ; Nuclear chemistry ; Materials science ; Ethanol ; Organic chemistry Catalytic Processes in Materials Science ; Gas Sensing Nanomaterials and Sensors ; Plasma Applications and Diagnostics
Authors: Dominik Hinrichs | Rasmus Himstedt | Dirk Dorfs
Source: Nanoscale (article, 2018-01-01)
Field: Materials Science — Materials Chemistry

The size-selective interaction of key and lock nanocrystals driven by depletion attraction at the nanoscale In this article, we study the size-dependent interactions of quasi-spherical nanocrystals with voids of concave nanoparticles of complementary sizes and shapes. Experimental insights into a system with key and lock particles with smaller dimensions than 15 nm are presented, which provide evidence for key-lock specific interaction on this length scale. Using depletion attraction as a driving force, the key-lock interaction is shown to be reversible and independent of the material composition of the key particles. Poly(ethylene glycol) methacrylate was utilized as a depletion agent in toluene, the solvent of the studied key-lock system. For this work, a model system of specifically developed concave manganese oxide nanocrystals, synthesized via a cast-mold approach, in combination with highly monodisperse quasi-spherical gold nanocrystals, was investigated with transmission electron microscopy, optical UV/vis/NIR spectroscopy and powder X-ray diffraction. Size-dependent key-lock interactions are clearly identified to occur. For geometrical reasons, only key particles with smaller particle diameters than the voids of the complementary lock particles are able to enter the void. So the void diameter of the lock particles sets a diameter threshold for the key-lock interaction. Additionally, other key particles like silver, iron oxide and even core-shell structured gold-nickel sulfide nanocrystals show key-in-lock assemblies with concave manganese oxide nanocrystals. This behaviour might open up new routes for size-selective particle sensing. Nanocrystal ; Nanoscopic scale ; Materials science ; Nanotechnology ; Lock (firearm) ; Attraction ; Key (lock) ; Nanoparticle ; Chemical physics ; Computer science ; Physics Pickering emulsions and particle stabilization ; Proteins in Food Systems ; Surfactants and Colloidal Systems
Authors: Luciano Canovese | Fabiano Visentin | Thomas Scattolin | Claudio Santo | V. Bertolasi
Source: Polyhedron (article, 2018-01-31)
Field: Chemistry — Organic Chemistry

Synthesis of novel olefin complexes of palladium(0) bearing monodentate NHC, phosphine and isocyanide spectator ligands Chemistry ; Phosphine ; Isocyanide ; Denticity ; Olefin fiber ; Palladium ; Catalysis ; Medicinal chemistry ; Polymer chemistry ; Organic chemistry ; Metal N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Synthetic Organic Chemistry Methods ; Catalytic Cross-Coupling Reactions