jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Samih A. Halawy | Ahmed I. Osman | David W. Rooney
Source: Energy Science & Engineering (article, 2022-04-25)
Field: Materials Science — Materials Chemistry

Highly basic and active ZnO–<i>x</i>% K<sub>2</sub>O nanocomposite catalysts for the production of methyl ethyl ketone biofuel Abstract Herein we demonstrate the preparation and characterization of nanocrystalline ZnO, either pure or promoted with 1–10 wt.% K 2 O. All catalysts calcined at 400°C were in the nano‐crystallite scale as confirmed by X‐ray powder diffraction analysis in the 22.9–28.0 nm range. According to the CO 2 ‐temperature‐programmed desorption study using thermogravimetric analysis and differential scanning calorimetry techniques, they have a broad spectrum of surface basic sites. Because of the significance of methyl ethyl ketone (MEK) as a next‐generation biofuel candidate with high‐octane, low boiling point, and relatively high vapor pressure. The prepared catalysts were examined during the direct production of MEK via 2‐butanol (2B) dehydrogenation. Among catalysts tested, ZnO promoted with 1% K 2 O showed a superior catalytic activity towards the conversion of 2B to MEK, that is, 71.7% at a reaction temperature of 275°C. The selectivity for the production of MEK over all catalysts was ≥95% across all catalysts when using N 2 ‐gas as a carrier. The use of airflow in this reaction resulted in a clear loss of selectivity toward MEK production as well as the appearance of undesirable products such as acetone and methanol. All catalytic properties of catalysts, particularly those of moderate strength, were highly correlated with the distribution of surface basic sites. Finally, a reaction mechanism was proposed for the dehydrogenation of 2B, followed by the partial oxidation of MEK. Dehydrogenation ; Catalysis ; Thermogravimetric analysis ; Calcination ; Materials science ; Selectivity ; Nanocomposite ; Chemistry ; Chemical engineering ; Organic chemistry ; Nanotechnology Catalytic Processes in Materials Science ; Catalysis and Hydrodesulfurization Studies ; Catalysis for Biomass Conversion
Authors: Mohamad Zaenudin | M. N. Mohammed | Adhes Gamayel
Source: International Journal of Integrated Engineering (review, 2022-06-21)
Field: Materials Science — Materials Chemistry

A Review on Molecular Dynamics Simulation of Joining Carbon-Nanotubes and Nanowires: Joining and Properties Carbon-nanotubes (CNTs) and Nanowires (NWs), the two nanomaterials with outstanding properties, are the materials with which their behaviour and properties have long been drawing attention to researchers. However, the tiny nature of these two materials causes difficulties in describing and estimating their behaviour and properties, thus a numerical technique that considers the tiny nature of the materials like Molecular Dynamics (MD) simulation is a promising solution to this problem. Since the early utilization of MD simulation in the investigation of the behaviour of carbon-nanotubes and nanowires, it provides the researcher with an excellent description of how the two materials behave at atomic-scale and then estimate their properties. Recently, MD simulation of CNTs and NWs exhibit growth in the simulation size as with the growth of the computing capabilities. The size of the materials being simulated by MD simulation increased significantly in the recent year, thus giving possibility to achieve a better description of the behaviour and a more precise estimation of the properties. In this review, we provide an overview of the recent advances in the investigation of the joining processes and properties of carbon-nanotubes and nanowires at atomic-scale utilizing molecular dynamics simulation. Carbon nanotube ; Molecular dynamics ; Nanowire ; Nanotechnology ; Materials science ; Nanomaterials ; Computational chemistry ; Chemistry Carbon Nanotubes in Composites ; Graphene research and applications ; Thermal properties of materials
Authors: Zuliana Madung | Sabrina Soloi | Mohd hafiz Abdul majid | Mohd Sani Sarjadi
Source: Biodiversitas Journal of Biological Diversity (article, 2022-03-04)
Field: Materials Science — Biomaterials

Production and characterization of Imperata cylindrica paper using potassium hydroxide as pulping agent Abstract. Madung Z, Soloi S, Majid MHA, Sarjadi MS. 2022. Production and characterization of Imperata cylindrica paper using potassium hydroxide as pulping agent. Biodiversitas 23: 1490-1494. Non-woody plants have become an alternative fiber in paper production as woods, the primary sources of papers have become limited due to increasing demand of paper year by year. Imperata cylindrica or cogon grass as the source of fiber for the pulp and paper industry in replacing the wood fiber because it has high cellulose and low lignin content. In this study, cogon grasses were treated with various concentrations of potassium hydroxide, KOH (5%, 8%, 10% and 12%). The effects of alkali treatment on the properties of the papers were investigated in the present study. Scanning Electron Microscope (SEM) image of the paper sheet indicates that the amount of cellulose fiber and other materials were lessening toward a higher concentration of KOH treatment. This explained that most of the lignin was entirely removed and some cellulose probably degraded at higher KOH concentrations. Fourier Transform Infa-Red (FTIR) analysis showed that the peaks at range 1650 cm-1-1630 cm-1 attributed to the presence of v(C=C) aromatic ring of lignin disappeared at 10% and 12% of KOH. The mechanical strength of the papers decreased with an increasing concentration of KOH, while 5% of KOH produced the highest value of tensile strength. Imperata ; Potassium hydroxide ; Lignin ; Cellulose ; Pulp and paper industry ; Fourier transform infrared spectroscopy ; Pulp (tooth) ; Ultimate tensile strength ; Potassium ; Nuclear chemistry ; Fiber ; Cellulose fiber ; Materials science ; Chemistry ; Hydroxide ; Composite material ; Chemical engineering ; Botany ; Organic chemistry ; Biology Advanced Cellulose Research Studies ; Lignin and Wood Chemistry ; Wood and Agarwood Research
Authors: Zi Yang | Can Li | Xingchen Liu | Xinyu Li | Na Yu | Yi Ren
Source: Angewandte Chemie (article, 2022-09-16)
Field: Materials Science — Materials Chemistry

Facile Route to Novel Diazaphosphinine‐Based Polycyclic Aromatic Hydrocarbons Abstract Doping main‐group elements has become a unique strategy to fine‐tune optoelectronic properties of organic π‐conjugated molecules. Herein, we report the first example of diazaphosphinine based polycyclic hydrocarbons (DP‐PAHs) via facile synthetic protocols. Synthesis of diazaphosphinine heterocycles harnesses mild and efficient P−N chemistry. The heterocycles readily undergo photocyclizations by using only oxidants. The photocyclization protocol is applicable to the heterocycles with various P‐centers. We successfully extended the protocols in extended DP‐PAHs with 13‐fused aromatic rings. Further adjusting P‐chemistry allows to efficiently fine‐tune the singlet and triplet emission characteristics. More importantly, single‐molecule white‐light‐emitting character was achieved via the balanced singlet and triplet emission of DP‐PAH. Therefore, this work opens up new horizons in the area of organic π‐conjugated materials. Conjugated system ; Chemistry ; Molecule ; Singlet state ; Singlet oxygen ; Combinatorial chemistry ; Photochemistry ; Aromaticity ; Organic chemistry ; Polymer ; Excited state ; Oxygen Luminescence and Fluorescent Materials ; Organoboron and organosilicon chemistry ; Synthesis and Properties of Aromatic Compounds
Authors: Anatoliy A. Vereshchagin | Vasiliy V. Potapenkov | Petr S. Vlasov | Daniil A. Lukyanov | Oleg V. Levin
Source: Nanomaterials (article, 2022-06-03)
Field: Materials Science — Polymers and Plastics

Optimization of Sulfonated Polycatechol:PEDOT Energy Storage Performance by the Morphology Control Anionic catechol-containing polymers represent a promising class of functional dopants for the capacity improvement of conductive polymers. For example, sulfonated poly(vinylcatechol) SPVC with outstanding theoretical capacity was used as a dopant for poly(ethylenedixythiophene) (PEDOT) conductive polymer, increasing its energy storage performance. However, such materials suffer from insufficient utilization of the theoretical capacity of SPVC originating from non-optimal morphology. In the present study, we performed systematic optimization of the composition and morphology of the PEDOT:SPVC material as a function of the deposition parameters to overcome this problem. As a result, a capacity of 95 mAh·g<sup>-1</sup> was achieved in a thin film demonstrating considerable electrochemical stability: 75% capacity retention after 100 cycles and 57% after 1000 cycles. Since the capacity was found to suffer from thickness limitation, a nanocomposite of PEDOT:SPVC and single-walled carbon nanotubes with high PEDOT:SPVC loading was fabricated, yielding the capacitance 178 F·g<sup>-1</sup> or 89 F·cm<sup>-2</sup>. The capacity values exceed non-optimized film twofold for thin film and 1.33 times for nanocomposite with carbon nanotubes. The obtained results demonstrate the importance of fine-tuning of the composition and morphology of the PEDOT:SPVC materials to ensure optimal interactions between the redox/anionic and conductive components. PEDOT:PSS ; Materials science ; Dopant ; Chemical engineering ; Conductive polymer ; Capacitance ; Nanocomposite ; Electrical conductor ; Carbon nanotube ; Polymer ; Composite material ; Doping ; Nanotechnology ; Chemistry ; Optoelectronics ; Electrode Conducting polymers and applications ; Supercapacitor Materials and Fabrication ; Advanced Sensor and Energy Harvesting Materials
Authors: Eivind Andreas Strømsodd | Audun Formo Buene | David Moe Almenningen | Odd R. Gautun | Bård Helge Hoff
Source: Dyes and Pigments (article, 2022-11-13)
Field: Chemistry — Organic Chemistry

Strategies for successful Suzuki-Miyaura cross-couplings with thienylboronic acids: From model studies to dye structures Suzuki-Miyaura cross-coupling is a convenient way for preparing thienyl containing dyes and bioactive molecules. However, reactions with thienylboronic acids can be troublesome. To understand these reactions in more depth, we herein present our investigation into the cross-coupling of (5-formylthiophen-2-yl)boronic acid with 4-bromoanisole as a model reaction. The study includes variations of catalyst, base, aryl halide type, temperature and reaction medium. A key to succeed with such cross-couplings is a highly active catalyst, and sufficient solubility of both the boronic acid and the aryl halide. XPhos precatalysts proved to be the best system for the model reaction, while other catalysts might be applicable provided that more boronic acid is added, or an aryl iodide is used as cross-coupling partner. The XPhos 4th generation precatalyst was also efficient for the construction of mono- and di-thiophene-2-carbaldehyde substituted phenothiazines and a triarylamine dye precursor. However, each cross-coupling pair needs fine tuning of the reaction medium to maximize yield. Aryl ; Chemistry ; Halide ; Catalysis ; Combinatorial chemistry ; Coupling reaction ; Boronic acid ; Aryl halide ; Iodide ; Yield (engineering) ; Suzuki reaction ; Organic chemistry ; Materials science ; Alkyl Sulfur-Based Synthesis Techniques ; Catalytic Cross-Coupling Reactions ; Radical Photochemical Reactions
Authors: Amine Garci | Seifallah Abid | Arthur H. G. David | Marcos D. Codesal | Luka Đorđević∞ | Ryan M. Young | Hiroaki Sai | Laura Le Bras | Aurélie Perrier | Marco Ovalle | P. Brown | Charlotte L. Stern | Araceli G. Campaña | Samuel I. Stupp | Michael R. Wasielewski | Víctor Blanco | J. Fraser Stoddart
Source: Angewandte Chemie (article, 2022-07-29)
Field: Chemistry — Organic Chemistry

Aggregation‐Induced Emission and Circularly Polarized Luminescence Duality in Tetracationic Binaphthyl‐Based Cyclophanes Abstract Here, we report an approach to the synthesis of highly charged enantiopure cyclophanes by the insertion of axially chiral enantiomeric binaphthyl fluorophores into the constitutions of pyridinium‐based macrocycles. Remarkably, these fluorescent tetracationic cyclophanes exhibit a significant AIE compared to their neutral optically active binaphthyl precursors. A combination of theoretical calculations and time‐resolved spectroscopy reveal that the AIE originates from limited torsional vibrations associated with the axes of chirality present in the chiral enantiomeric binaphthyl units and the fine‐tuning of their electronic landscape when incorporated within the cyclophane structure. Furthermore, these highly charged enantiopure cyclophanes display CPL responses both in solution and in the aggregated state. This unique duality of AIE and CPL in these tetracationic cyclophanes is destined to be of major importance in future development of photonic devices and bio‐applications. Enantiopure drug ; Cyclophane ; Enantiomer ; Luminescence ; Pyridinium ; Chirality (physics) ; Chemistry ; Supramolecular chemistry ; Stereochemistry ; Crystallography ; Materials science ; Enantioselective synthesis ; Physics ; Crystal structure ; Organic chemistry ; Optoelectronics ; Symmetry breaking ; Quantum mechanics Synthesis and Properties of Aromatic Compounds ; Luminescence and Fluorescent Materials ; DNA and Nucleic Acid Chemistry
Authors: Ya Wu | Zhiwei Lin | Rongmiao Fang | Yingying Guo | Li Tu | Yikun Yan | Weiqiang Zhang | Huaming Sun | Ziwei Gao
Source: Organometallics (article, 2022-04-29)
Field: Chemistry — Organic Chemistry

Titanocene Lewis Acid Complexes with Diversified N,O-Ligands: Selectivity toward Three-Component Friedel–Crafts Reactions of Indoles Titanocene complexes by N,O-ligands were rationally designed and tuned for selective three-component aza-Friedel–Crafts reactions of indoles, aldehydes, and unmodified aniline. The combination of Cp2TiCl2 and 8-hydroxyquinoline favored the synthesis of the mono aza-Friedel–Crafts adducts, whereas Cp2TiCl2 combined with anthranilic acid overwhelmingly formed bis-indoles. 1H NMR titration experiments, mass spectroscopy, X-ray crystal structure analyses, and control experiments showed that the reaction of Cp2TiCl2 with 8-hydroxyquinoline resulted in a half-sandwich complex [CpTiCl(C9H6NO)2] (I), in which the Lewis acidity was enhanced via fine-tuning steric and electronic properties of the Ti (IV) center, facilitating mono aza-Friedel–Crafts reaction of indoles, aldehydes, and aniline; in contrast, when anthranilic acid reacted with the same Ti(IV) precursor, a bis-ligand sandwich complex Cp2Ti[(o-NH2)PhCOO]2 (II) was obtained, in which both Lewis acidity of titanium and cooperation with amino groups promoted further transformation of indoles into bis-indole adducts. Chemistry ; Anthranilic acid ; Aniline ; Adduct ; Lewis acids and bases ; Friedel–Crafts reaction ; Steric effects ; Ligand (biochemistry) ; Indole test ; Medicinal chemistry ; Organic chemistry ; Catalysis Synthetic Organic Chemistry Methods ; Asymmetric Synthesis and Catalysis ; Catalytic C–H Functionalization Methods
Authors: Guang‐Juan Xu | Shu-Ran Zhang | Wei Xie | Li Wang | Xiangxin Xue | Yu Qiao | Zhanlin Xu | Zhong‐Min Su
Source: Journal of Polymer Research (article, 2022-04-01)
Field: Materials Science — Materials Chemistry

Tuning the porosity of ionic covalent triazine frameworks using auxiliary monomers for highly efficient CO2 and I2 capture Ionic bonding ; Monomer ; Triazine ; Materials science ; Covalent bond ; Adsorption ; Porosity ; Chemical engineering ; Ionic liquid ; Polymer chemistry ; Ion ; Physical chemistry ; Organic chemistry ; Chemistry ; Catalysis ; Composite material ; Polymer Covalent Organic Framework Applications ; Metal-Organic Frameworks: Synthesis and Applications ; Membrane Separation and Gas Transport
Authors: Yong Zhang | Jianchen Lu | Yang Li | Baijin Li | Zilin Ruan | Hui Zhang | Zhenliang Hao | Shijie Sun | Wei Xiong | Lei Gao | Long Chen | Jinming Cai
Source: Angewandte Chemie (article, 2022-04-22)
Field: Materials Science — Materials Chemistry

On‐Surface Synthesis of a Nitrogen‐Doped Graphene Nanoribbon with Multiple Substitutional Sites Doped graphene nanoribbons (GNRs) with heteroatoms are a principal strategy to fine-tune the electronic structures of GNRs for future device applications. Here, we successfully synthesized the N=9 nitrogen-doped armchair GNR on the Au(111) surface. Due to the flexibility of precursor molecules, three different covalent bonds (C-C, C-N, N-N) are formed in the GNR backbone. Scanning tunneling spectroscopy analysis together with band structure calculations reveals that the band gap of the N-9-AGNRs (C-C) will be enlarged compared to pristine 9-AGNRs, and the C-N bond and N-N bond at the isolated site of N-9-AGNR (C-C) will introduce new defect states near the Fermi level. DFT calculations reveal that the electronic structure of N-9-AGNR (C-C) shows semiconductor character, while N-9-AGNR (C-N) and N-9-AGNR (N-N) display metallic character. Our results provide a promising route for creating more complex molecular heterostructures with tunable band gaps, which may be useful for future molecular electronics and memory device applications. Heteroatom ; Materials science ; Covalent bond ; Graphene nanoribbons ; Graphene ; Fermi level ; Doping ; Band gap ; Heterojunction ; Electronic structure ; Molecular electronics ; Scanning tunneling spectroscopy ; Crystallography ; Molecule ; Nanotechnology ; Scanning tunneling microscope ; Chemistry ; Optoelectronics ; Computational chemistry ; Ring (chemistry) ; Physics Graphene research and applications ; Surface Chemistry and Catalysis ; Molecular Junctions and Nanostructures
Authors: Jelena Zagorac | Dejan Zagorac | Biljana Babić | T. A. Prikhna | Branko Matović
Source: Journal of Solid State Chemistry (article, 2022-04-15)
Field: Materials Science — Materials Chemistry

Effect of aluminum addition on the structure and electronic properties of boron nitride Boron nitride ; Nitride ; Materials science ; Wurtzite crystal structure ; Band gap ; Electronic structure ; Ab initio ; Boron ; Aluminium ; Thermal stability ; Inorganic chemistry ; Nanotechnology ; Computational chemistry ; Metallurgy ; Chemistry ; Zinc ; Optoelectronics ; Layer (electronics) ; Organic chemistry Boron and Carbon Nanomaterials Research ; GaN-based semiconductor devices and materials ; Metal and Thin Film Mechanics
Authors: Shuo Zhang | Xing‐Xing Shen | Yu Tian | Yihan Fu | Mengze Li | Shuran Li | Weidong Zhu | An Li | Keping Yan
Source: Separation and Purification Technology (article, 2022-10-30)
Field: Materials Science — Surfaces, Coatings and Films

The turbulent-flow-assisted electrostatic collection and alignment of recycled short-chopped carbon fiber in gaseous phase Materials science ; Composite material ; Turbulence ; Anisotropy ; Fiber ; Composite number ; Optics ; Mechanics Surface Modification and Superhydrophobicity ; Electrohydrodynamics and Fluid Dynamics ; Microfluidic and Bio-sensing Technologies
Authors: Xinlong Zeng | Wenyu Kang | Xiaowen Zhou | Linglong Li | Yuanzheng Xia | Haiyang Liu | Chengbiao Yang | Yaping Wu | Zhiming Wu | Xu Li | Junyong Kang
Source: Science China Materials (article, 2022-08-18)
Field: Materials Science — Materials Chemistry

Modulating the intralayer and interlayer valley excitons in WS2 through interaction with AlGaN Exciton ; Monolayer ; Condensed matter physics ; Materials science ; Bilayer ; Polarization (electrochemistry) ; Scattering ; Doping ; Biexciton ; Electron ; Coupling (piping) ; Optoelectronics ; Physics ; Nanotechnology ; Optics ; Chemistry ; Membrane 2D Materials and Applications ; MXene and MAX Phase Materials ; Perovskite Materials and Applications
Authors: Yuanyuan Qin | Yuewei Wu | Shuchang Luo | Jing Xi | Yan Guo | Yi Ding | Jun Zhang | Xiangyu Liu
Source: Dalton Transactions (article, 2022-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Modulation of the magnetic dynamics of pentagonal-bipyramidal Co(<scp>ii</scp>) complexes by fine-tuning the coordination microenvironment Four air-stable mononuclear Co(II) complexes, with the formulas [Co(dapbh)(H<sub>2</sub>O)(CH<sub>3</sub>OH)] (1), [Co(Hdapbh)(N<sub>3</sub>)(CH<sub>3</sub>OH)]·(CH<sub>3</sub>OH) (2), [Co(H<sub>2</sub>aapbh)(CH<sub>3</sub>OH)<sub>2</sub>]·(NO<sub>3</sub>)<sub>2</sub> (3) and [Co(H<sub>2</sub>bapbh)(H<sub>2</sub>O)(NO<sub>3</sub>)]·(NO<sub>3</sub>) (4), have been synthesized and structurally characterized by single crystal X-ray diffraction. In all of the complexes, the Co(II) centers constrained by the rigid pentadentate ligand H<sub>2</sub>L<sup>R</sup> with two protonable hydrogens adopt a heptacoordinated pentagonal-bipyramidal geometry. The combined analyses of magnetic data and <i>ab initio</i> calculations unveil large easy-plane magnetic anisotropies for these complexes (<i>D</i> = +37.338, +37.273, +41.138 and +41.139 cm<sup>-1</sup> for 1-4, respectively), which indicate that the chemical alterations of the equatorial ligand and the ligand field strength in the axial positions synergistically fine-tune the magnitude of the <i>D</i> values. Magnetic investigations demonstrate the field-induced single-ion magnetic behavior in complexes 1, 2 and 4 with diverse energy barriers (<i>U</i><sub>eff</sub>) of 12.25 for 1, 44.15 for 2 and 48.72 K for 4, corresponding to the geometrical distortion of the heptacoordinated Co(II) ion. That is, the greatest deviation from the ideal <i>D</i><sub>5h</sub> symmetry in 4 is responsible for the highest barrier. Pentagonal bipyramidal molecular geometry ; Crystallography ; Ligand (biochemistry) ; Chemistry ; Ion ; Coordination sphere ; Ligand field theory ; Magnetic anisotropy ; Coordination geometry ; Ab initio ; Magnetic moment ; Magnetic susceptibility ; Ab initio quantum chemistry methods ; Magnetic field ; Crystal structure ; Condensed matter physics ; Physics ; Molecule ; Magnetization ; Receptor Magnetism in coordination complexes ; Metal-Organic Frameworks: Synthesis and Applications ; Metal complexes synthesis and properties