jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Zhuwen Chen | Lei Dong | Chao Chen | Yanding Wang | Ya Wang | Jian Zhang | Wei Qian | Mei Hong
Source: Nanoscale (article, 2019-01-01)
Field: Chemistry — Inorganic Chemistry

Direct synthesis of core–shell MFI zeolites with spatially tapered trimodal mesopores <i>via</i> controlled orthogonal self-assembly Manipulating pore hierarchy in porous materials is an attractive, yet difficult challenge in crystalline zeolites. Here, we report core-shell MFI zeolites having trimodal mesopores with size gradually decreasing from the surface to the core, synthesized through a one-pot approach via controlled orthogonal self-assembly. The novel spatially resolved mesopore structures are ascribed to the nanoscale phase separation between mutually coupled interactions of organosilane supramolecular assembly and zeolite framework ordering. The highly hierarchical zeolite architecture with tapered mesopore distribution allowed for spatially resolved adsorption of florescent molecules, improved catalytic performance in condensation reactions, and an enhanced nanoreactor for coupling reactions due to alleviated diffusion limitations. The successful synthesis of fine-tuned zeolites with larger mesopores gradually subdivided into smaller mesopores (hierarchy-type I) may open up possibilities for emergent new porous structures exhibiting a higher degree of hierarchies that are currently inaccessible to many crystalline oxide or related materials. Materials science ; Mesoporous material ; Shell (structure) ; Core (optical fiber) ; Chemical engineering ; Zeolite ; Composite material ; Organic chemistry ; Catalysis ; Chemistry Zeolite Catalysis and Synthesis ; Mesoporous Materials and Catalysis ; Catalysis and Hydrodesulfurization Studies
Authors: Shuanghong Zhang | Qian‐Hong Wan | Yan Li
Source: Journal of Separation Science (article, 2019-06-21)
Field: Chemistry — Spectroscopy

Epoxide‐derived mixed‐mode chromatographic stationary phases for separation of active substances in fixed‐dose combination drugs A method for the preparation of novel mixed-mode reversed-phase/strong cation exchange stationary phase for the separation of fixed-dose combination drugs has been developed. An epoxysilane bonded silica prepared by vapor phase deposition was used as a starting material to produce diol, octadecyl, sulfonate, and mixed octadecyl/sulfonate groups bonded silica phases. The chemical structure and surface coverage of the functional groups on these synthesized phases were confirmed by fourier-transform infrared and solid-state <sup>13</sup> C NMR spectroscopy and elemental analysis. Alkylbenzene homologs, basic drugs, nucleobases and alkylaniline homologs were used as probes to demonstrate the reversed-phase, ion exchange, hydrophilic interaction and mixed-mode retention behaviors of these stationary phases. The octadecyl/sulfonate bonded silica exhibits pronounced mixed-mode retention behavior and superior retentivity and selectivity for alkylaniline homologs. The mixed-mode retention is affected by either ionic or solvent strength in the mobile phase, permiting optimization of a separation by fine tuning these parameters. The mixed-mode stationary phase was applied to separate two fixed-dose combination drugs: compound reserpine tablets and compound methoxyphenamine capsules. The results show that simultaneous separation of multiple substances in the compound dosage can be achieved on the mixed-mode phase, which makes multi-cycles of analysis for multiple components obsolete. Chemistry ; Phase (matter) ; Sulfonate ; Ion exchange ; Chromatography ; Selectivity ; Solvent ; Ion ; Organic chemistry Analytical Chemistry and Chromatography ; Microfluidic and Capillary Electrophoresis Applications ; Protein purification and stability
Authors: Agata Pomorska | Karol Wolski | Magdalena Wytrwał-Sarna | Andrzej Bernasik | Szczepan Zapotoczny
Source: European Polymer Journal (article, 2019-01-05)
Field: Materials Science — Surfaces, Coatings and Films

Polymer brushes grafted from nanostructured zinc oxide layers – Spatially controlled decoration of nanorods Nanorod ; Materials science ; Chemical engineering ; Atom-transfer radical-polymerization ; Quartz crystal microbalance ; Polymer ; Polymerization ; Nanocomposite ; Polymer chemistry ; Nanotechnology ; Adsorption ; Composite material ; Organic chemistry ; Chemistry Polymer Surface Interaction Studies ; Hydrogels: synthesis, properties, applications ; Advanced Sensor and Energy Harvesting Materials
Authors: I. Alves | Alexandre L. Magalhães
Source: The Journal of Physical Chemistry A (article, 2019-08-27)
Field: Materials Science — Materials Chemistry

BN-Doped Graphene and Single-Walled Carbon Nanotubes for the Catalysis of S<sub>N</sub>2 Reactions: Insights from Density Functional Theory Modeling The inner space of carbon nanotubes has already been proven to provide a type of confinement, which can dramatically alter the energetics of chemical reactions when compared to the gas phase. Moreover, BN doping can be used to fine-tune electronic properties, which might influence the enthalpy and activation energy of chemical reactions that take place inside their inner space. The energy profile of the prototype Menshutkin S<sub>N</sub>2 reaction between ammonia and chloromethane has been analyzed in a variety of carbon-based materials at the DFT (density functional theory) level. Pristine zigzag (9,0) and (12,0) single-walled carbon nanotubes and graphene sheets have been doped with boron and nitrogen at different stoichiometries, namely, BN, BNC, BNC<sub>2</sub>, and BNC<sub>4</sub>, that resulted in remarkable variations of their catalytic effects. Graphene has revealed to be the support material, which depends less on doping in terms of enthalpy and energy barrier of the reaction. However, when graphene is rolled up into tubular forms, the influence of doping becomes increasingly stronger as the nanotube radius decreases. In the case of BNC<sub>4</sub> doping of (9,0) nanotubes, the activation energy drops 10 kcal/mol when compared to the pristine case, and the reaction became even exothermic by more than 15 kcal/mol. Graphene ; Carbon nanotube ; Materials science ; Density functional theory ; Exothermic reaction ; Doping ; Catalysis ; Enthalpy ; Nanotechnology ; Carbon fibers ; Chemical physics ; Chemical engineering ; Computational chemistry ; Thermodynamics ; Chemistry ; Organic chemistry ; Composite material Graphene research and applications ; Ammonia Synthesis and Nitrogen Reduction ; Boron and Carbon Nanomaterials Research
Authors: Akiko Yagi | Yasutomo Segawa | Kenichiro Itami
Source: Chem (article, 2019-04-01)
Field: Materials Science — Materials Chemistry

Armchair and Chiral Carbon Nanobelts: Scholl Reaction in Strained Nanorings Nanoring ; Carbon nanotube ; Chirality (physics) ; Materials science ; Nanotechnology ; Carbon fibers ; Zigzag ; Graphene ; Asymmetric carbon ; Chemistry ; Composite material ; Physics ; Organic chemistry ; Composite number Carbon Nanotubes in Composites ; Graphene research and applications ; Synthesis and Properties of Aromatic Compounds
Authors: Levent Pelit | Füsun Okçu Pelit | Hasan Ertaş | F. Nil Ertaş
Source: Current Analytical Chemistry (article, 2019-03-14)
Field: Chemistry — Analytical Chemistry

Electrochemically Fabricated Solid Phase Microextraction Fibers and Their Applications in Food, Environmental and Clinical Analysis Background: Designing an analytical methodology for complicated matrices, such as biological and environmental samples, is difficult since the sample preparation procedure is the most demanding step affecting the whole analytical process. Nowadays, this step has become more challenging by the legislations and environmental concerns since it is a prerequisite to eliminate or minimize the use of hazardous substances in traditional procedures by replacing with green techniques suitable for the sample matrix. Methods: In addition to the matrix, the nature of the analyte also influence the ease of creating green analytical techniques. Recent developments in the chemical analysis provide us new methodologies introducing microextraction techniques and among them, solid phase microextraction (SPME) has emerged as a simple, fast, low cost, reliable and portable sample preparation technique that minimizes solvent consumption. Results: The use of home-made fibers is popular in the last two decades since the selectivity can be tuned by changing the surface characteristics through chemical and electrochemical modifications. Latter technique is preferred since the electroactive polymers can be coated onto the fiber under controlled electrochemical conditions and the film thicknesses can be adjusted by simply changing the deposition parameters. Thermal resistance and mechanical strength can be readily increased by incorporating different dopant ions into the polymeric structure and selectivity can be tuned by inserting functional groups and nanostructures. A vast number of analytes with wide range of polarities extracted by this means can be determined with a suitable chromatographic detector coupled to the system. Therefore, the main task is to improve the physicochemical properties of the fiber along with the extraction efficiency and selectivity towards the various analytes by adjusting the electrochemical preparation conditions. Conclusion: This review covers the fine tuning conditions practiced in electrochemical preparation of SPME fibers and in-tube systems and their applications in environmental, food and clinical analysis. Solid-phase microextraction ; Analyte ; Sample preparation ; Materials science ; Matrix (chemical analysis) ; Nanotechnology ; Environmental analysis ; Process engineering ; Computer science ; Chromatography ; Chemistry ; Composite material ; Mass spectrometry Analytical chemistry methods development ; Electrochemical Analysis and Applications ; Biosensors and Analytical Detection
Authors: Bahri Gür | Kadem Meral
Source: Journal of Molecular Structure (article, 2019-07-12)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Characterization of merocyanine 540-octadecylamine thin films fabricated by Langmuir-Blodgett and Spin-Coating techniques Chemistry ; Langmuir–Blodgett film ; Characterization (materials science) ; Spin coating ; Merocyanine ; Coating ; Nanotechnology ; Thin film ; Chemical engineering ; Organic chemistry ; Molecule Liquid Crystal Research Advancements ; Surfactants and Colloidal Systems ; Block Copolymer Self-Assembly
Authors: Narayanan Krishnamurthy | Siddharth Maddali | Jeffrey A. Hawk | Vyacheslav Romanov
Source: Computational Materials Science (article, 2019-03-23)
Field: Materials Science — Materials Chemistry

9Cr steel visualization and predictive modeling Bivariate analysis ; Univariate ; Normalization (sociology) ; Computer science ; Visualization ; Skewness ; Random forest ; Context (archaeology) ; Data mining ; Materials science ; Artificial intelligence ; Machine learning ; Multivariate statistics ; Statistics ; Mathematics Machine Learning in Materials Science ; Hydrogen embrittlement and corrosion behaviors in metals ; Microstructure and Mechanical Properties of Steels
Authors: Mi Zhang | Zhibin Shao | Tianhao Jiang | Xiaofeng Wu | Bingchang Zhang | Xiujuan Zhang | Feifei Xia | Jiansheng Jie
Source: The Journal of Physical Chemistry C (article, 2019-06-01)
Field: Materials Science — Materials Chemistry

Tuning Electrical and Raman Scattering Properties of Cadmium Sulfide Nanoribbons via Surface Charge Transfer Doping Surface charge transfer doping (SCTD) has emerged as an efficient approach to tune the electrical and optical properties of semiconductor nanostructures. As an important II–VI semiconductor, cadmium sulfide (CdS) nanostructures possess superior optoelectronic properties. However, the SCTD on the CdS nanostructures remains a challenge, and the underlying mechanism for optical property modulation is unclear. Herein, we demonstrate that both the electrical and Raman scattering properties of CdS nanoribbons (NRs) can be tuned by using MoO3 and benzyl viologen (BV) as surface dopants. The MoO3 (or BV) molecules, which have a high work function (or strong reducing capability), can extract (or inject) electrons from (or into) the CdS NRs because of the large difference in energy levels, leading to electron depletion (or accumulation) within the CdS NRs. By controlling the amount of surface dopants, the electron concentration as well as resistivity of the CdS NRs can be readily modulated. Significantly, Raman scattering properties of the CdS NRs can be fine-tuned due to a strong electron–phonon coupling effect. A mechanism based on the semiclassical longitudinal–optical–phonon–plasmon theory is first proposed to explain the SCTD-induced Raman scattering modulation. Our findings offer a feasible route for the modulation of the electrical and optical properties of compound semiconductor nanostructures. Materials science ; Dopant ; Raman scattering ; Doping ; Semiconductor ; Raman spectroscopy ; Optoelectronics ; Scattering ; Nanotechnology ; Optics 2D Materials and Applications ; Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films
Authors: Ashraf M. Zenkour | Farzad Ebrahimi | Mohammad Reza Barati
Source: International journal of nanodimension. (article, 2019-04-01)
Field: Materials Science — Materials Chemistry

Buckling analysis of a size-dependent functionally graded nanobeam resting on Pasternak's foundations Buckling analysis of a functionally graded (FG) nanobeam resting on two-parameter elastic foundation is presented based on third-order shear deformation beam theory (TOSDBT). The in-plane displacement of TOSDBT has parabolic variation through the beam thickness. Also, TOSDBT accounts for shear deformation effect and verifies stress-free boundary conditions on upper and lower faces of FG nanobeam. The two-parameter elastic foundation model including linear Winkler's springs along with Pasternak's shear layer is in contact with the beam in deformation. Material properties of FG nanobeam are supposed to vary gradually along the thickness according to both power-law and Mori–Tanaka laws. Small-scale effect of Eringen's nonlocal elasticity theory has been considered. Nonlocal equilibrium equations are obtained based on the minimum potential energy principle and solved analytically. The accuracy of current method is examined by comparing current results with the available ones in literature. Effects of foundation parameters, gradient index, nonlocal parameter and slenderness ratio on buckling behavior of FG nanobeams are examined. Buckling ; Boundary value problem ; Beam (structure) ; Materials science ; Elasticity (physics) ; Mechanics ; Foundation (evidence) ; Shear (geology) ; Timoshenko beam theory ; Physics ; Mathematical analysis ; Mathematics ; Composite material ; Law ; Optics Nonlocal and gradient elasticity in micro/nano structures ; Composite Structure Analysis and Optimization ; Thermoelastic and Magnetoelastic Phenomena
Authors: Shirley Nakagaki | Kelly A. D. F. Castro | Maria G. P. M. S. Neves | M. Amparo F. Faustino | Yassuko Iamamoto
Source: Journal of the Brazilian Chemical Society (review, 2019-01-01)
Field: Materials Science — Materials Chemistry

The Research on Porphyrins and Analogues in Brazil: A Small Review Covering Catalytic and other Applications since the Beginning at Universidade de São Paulo in Ribeirão Preto until the Joint Venture between Brazilian Researchers and Colleagues from Universidade de Aveiro, Portugal The synthetic versatility and the potential applications of porphyrins and analogues in different fields have aroused special interest in their study, especially to mimic biological systems, such as cytochrome P-450. The ability of the porphyrin tetrapyrrolic core to accommodate metal ions of varying charges can modulate the type of application of these compounds. As a contribution, in this special number in honor to the Brazilian women who have devoted their lives to the growth and dissemination of chemistry knowledge, we report the advances in porphyrin research in Brazil for catalytic purposes and other applications, beginning at the Universidade de So Paulo (USP) at Ribeiro Preto. We also discuss some works that have resulted from joint research effort between Brazilian researchers and Portuguese colleagues from the Universidade de Aveiro, Portugal, working in the porphyrin field. Joint (building) ; Catalysis ; Chemistry ; Engineering ; Organic chemistry ; Architectural engineering Porphyrin and Phthalocyanine Chemistry
Authors: Robert Konrath | Anke Spannenberg | Paul C. J. Kamer
Source: Chemistry - A European Journal (article, 2019-09-08)
Field: Chemistry — Inorganic Chemistry

Preparation of a Series of Supported Nonsymmetrical PNP‐Pincer Ligands and the Application in Ester Hydrogenation In contrast to their symmetrical analogues, nonsymmetrical PNP-type ligand motifs have been less investigated despite the modular pincer structure. However, the introduction of mixed phosphorus donor moieties provides access to a larger variety of PNP ligands. Herein, a facile solid-phase synthesis approach towards a diverse PNP-pincer ligand library of 14 members is reported. Contrary to often challenging workup procedures in solution-phase, only simple workup steps are required. The corresponding supported ruthenium-PNP catalysts are screened in ester hydrogenation. Usually, industrially applied heterogeneous catalysts require harsh conditions in this reaction (250-350 °C at 100-200 bar) often leading to reduced selectivities. Heterogenized reusable Ru-PNP catalysts are capable of reducing esters and lactones selectively under mild conditions. Pincer movement ; Catalysis ; Combinatorial chemistry ; Ligand (biochemistry) ; Ruthenium ; Chemistry ; Pincer ligand ; Organic chemistry ; Receptor Asymmetric Hydrogenation and Catalysis ; Synthetic Organic Chemistry Methods ; Catalytic Cross-Coupling Reactions
Authors: Kyosuke Isoda | Ayumi Ikenaga
Source: Crystals (article, 2019-01-17)
Field: Chemistry — Organic Chemistry

Synthesis of Furan-Substituted N-Heteroacene-Based Liquid Material and Its Acid-Recognizing Behavior In this study, we synthesized a novel N-heteroacene-based liquid material 6,7-bis(3,7,11-trimethyl-1-dodecyloxy)-2,3-difurylquinoxaline (RPNL 1), containing two furan rings. We revealed that RPNL 1 adopted a disordered liquid at 25 °C, determined by polarized optical microscopic observation, differential scanning calorimetry, and X-ray diffraction measurements. The fluorescent spectrum measurement revealed that RPNL 1 showed a blue emission at 25 °C. Dissolving benzene sulfonic acid (BSA) in RPNL 1 brought about dramatic changes in its physical properties, such as emission colors, as well as sample states. Upon recognizing BSA, photoluminescent color was changed into orange, as well as phase transition occurred from liquid to a liquid-crystalline phase. RPNL 1 can function as an acid-recognizing material, accompanied with the color changes in emission. Differential scanning calorimetry ; Photoluminescence ; Fluorescence ; Liquid crystal ; Furan ; Sulfonic acid ; Benzene ; Materials science ; Dissolution ; Analytical Chemistry (journal) ; Phase (matter) ; Diffraction ; Chemistry ; Organic chemistry ; Polymer chemistry ; Optics Synthesis and Biological Evaluation ; Synthesis and properties of polymers ; Luminescence and Fluorescent Materials
Authors: Bernhard Jandl | Sima Sedghiniya | Annika Carstens | Kira Astakhova
Source: ACS Omega (article, 2019-08-16)
Field: Materials Science — Biomaterials

Peptide–Fluorophore Hydrogel as a Signal Boosting Approach in Rapid Detection of Cancer DNA Cancer is a major health risk in the modern society that requires rapid, reliable, and inexpensive diagnostics. Because of the low abundance of cancer DNA in biofluids, current detection methods require DNA amplification. The amplification can be challenging; it provides only relative quantification and extends time and cost of an assay. Herein, we report a new oligonucleotide hybridization platform for amplification-free detection of human cancer DNA. Using a large PEG-capture probe allows rapid separation of the bound (mutant) versus unbound (wild type) DNA. Next, a supramolecular hydrogel forming peptide attached to a detection oligonucleotide probe serves as a signal amplification tool. Having screened multiple short peptides and fluorophores, we identified the system P1 + cyanine 3.5 that allows for sensitive quantitative detection of mutation L858R in <i>EGFR</i> oncogene. The peptide-fluorophore-based assay provides absolute target DNA quantification at the detection limit of 20 ng cancer DNA versus >500 ng for Cy3.5-labeled oligonucleotide in only 1 hour. Fluorophore ; Boosting (machine learning) ; DNA ; Cancer detection ; Chemistry ; Nanotechnology ; Biophysics ; Materials science ; Fluorescence ; Cancer ; Computer science ; Artificial intelligence ; Medicine ; Biochemistry ; Biology ; Internal medicine ; Optics ; Physics Supramolecular Self-Assembly in Materials ; Advanced biosensing and bioanalysis techniques ; RNA Interference and Gene Delivery
Authors: Laura Abis | Nikolaos Dimitratos | Meenakshisundaram Sankar | Simon J. Freakley | Graham J. Hutchings
Source: Catalysis Letters (article, 2019-09-11)
Field: Materials Science — Materials Chemistry

Plasmonic Oxidation of Glycerol Using Au/TiO2 Catalysts Prepared by Sol-Immobilisation Abstract Au nanoparticles supported on P25 TiO 2 (Au/TiO 2 ) were prepared by a facile sol-immobilisation method and investigated for the surface plasmon-assisted glycerol oxidation under base-free conditions. The Au/TiO 2 samples were characterized by UV–vis spectroscopy and transmission electron microscopy. Catalysts were prepared using polyvinyl alcohol as stabiliser as well as in the absence of polymer stabiliser. Both the conversion and the reaction selectivity are affected by the plasmon-assisted oxidation and there is an interplay between the presence of the stabiliser and the Au nanoparticle size. Graphic Abstract Stabiliser ; Catalysis ; Chemistry ; Glycerol ; Nanoparticle ; Polyvinyl alcohol ; Plasmon ; Selectivity ; Stabilizer (aeronautics) ; Chemical engineering ; Organometallic chemistry ; Transmission electron microscopy ; Alcohol oxidation ; Nuclear chemistry ; Inorganic chemistry ; Nanotechnology ; Organic chemistry ; Materials science Catalytic Processes in Materials Science ; Nanomaterials for catalytic reactions ; Mesoporous Materials and Catalysis