jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Weiwei Yang | Haohong Song | Lihua Zhang | Junyan Zhang | Felipe Polo‐Garzon | Haodong Wang | Harry M. Meyer | De‐en Jiang | Zili Wu | Yuanyuan Li
Source: ACS Catalysis (article, 2024-10-23)
Field: Materials Science — Materials Chemistry

Active Palladium Structures on Ceria Obtained by Tuning Pd–Pd Distance for Efficient Methane Combustion Efficiently removing/converting methane via methane combustion imposes challenges on catalyst design: how to design local structures of a catalytic site so that it has both high intrinsic activity and atomic efficiency? By manipulating the atomic distance of isolated Pd atoms, herein we show that the intrinsic activity of Pd catalysts can be significantly improved for methane combustion via a stable Pd2 structure on a ceria nanorod support. Guided by theory and confirmed by experiment, we find that the turnover frequency (TOF) of the Pd2 structure with the Pd–Pd distance of 2.99 Å is higher than that of the Pd2 structure with the Pd–Pd distance of 2.75 Å; at least 26 times that of ceria supported Pd single atoms and 4 times that of ceria supported PdO nanoparticles. The high intrinsic activity of the 2.99 Å Pd–Pd structure is attributed to the conductive local redox environment from the two O atoms bridging the two Pd2+ ions, which facilitates both methane adsorption and activation as well as the production of water and carbon dioxide during the methane oxidation process. This work highlights the sensitivity of catalytic behavior on the local structure of active sites and the fine-tuning of the metal–metal distance enabled by a support local environment for guiding the design of efficient catalysts for reactions that highly rely on Pt-group metals. Catalysis ; Methane ; Palladium ; Anaerobic oxidation of methane ; Chemistry ; Adsorption ; Metal ; Inorganic chemistry ; Nanorod ; Catalytic combustion ; Redox ; Materials science ; Chemical engineering ; Nanotechnology ; Physical chemistry ; Organic chemistry Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Advanced Photocatalysis Techniques
Authors: Z. Y. Khattari
Source: Radiation Physics and Chemistry (article, 2024-03-01)
Field: Materials Science — Materials Chemistry

The Hirshfeld topological surfaces, volumes, and their voids charge density interplay on radiation shielding properties: A case study of carbide-based ceramics Electromagnetic shielding ; Materials science ; Effective atomic number ; Charge density ; Silicon carbide ; Carbide ; Attenuation ; Analytical Chemistry (journal) ; Chemistry ; Composite material ; Physics ; Optics Radiation Shielding Materials Analysis ; Nuclear materials and radiation effects ; Nuclear Materials and Properties
Authors: Gaetana Paolella | Antonio Montefusco | Ivana Caputo | Giuliana Gorrasi | Gianluca Viscusi
Source: European Journal of Pharmaceutics and Biopharmaceutics (article, 2024-05-11)
Field: Materials Science — Biomaterials

Quercetin encapsulated polycaprolactone-polyvinylpyrrolidone electrospun membranes as a delivery system for wound healing applications Quercetin ; Membrane ; Polyvinylpyrrolidone ; Biocompatibility ; Polycaprolactone ; HaCaT ; Chemistry ; Drug delivery ; Wound healing ; Controlled release ; Materials science ; Chemical engineering ; Nanotechnology ; Polymer chemistry ; Polymer ; Organic chemistry ; Biochemistry ; Antioxidant ; Surgery Electrospun Nanofibers in Biomedical Applications ; Wound Healing and Treatments ; Silk-based biomaterials and applications
Authors: Özce Durak | Nitasha Habib | Hasan Can Gülbalkan | Ahmet Safa Aydogdu | Ray O. Ozdemir | Seda Keskın | Alper Uzun
Source: Chemical Engineering Journal (article, 2024-05-27)
Field: Chemistry — Inorganic Chemistry

Molecular engineering of a MOF with an ionic liquid sheath for direct air separation at ambient conditions Combining ionic liquids (ILs) with metal–organic frameworks (MOFs) offers broad prospects for gas separation applications. However, identifying the best IL-MOF pair for a target gas separation solely based on experimental techniques is impractical. Herein, the promising IL and MOF combination was selected among 35,672 distinct ILs and 5,629 different MOFs by fusing computational methods at different molecular scales, density functional theory, conductor-like screening model for real solvents calculations, and grand canonical Monte Carlo simulations to engineer a MOF with an IL sheath (MOFILS) for direct air separation. The new MOFILS composed of [P6,6,6,14][DCA] and PCN-250(Fe) designed at the atomic level was then experimentally synthesized after fine-tuning the MOF to achieve high-performance air separation. An exceptionally high ideal O2/N2 selectivity of 26 was reached at 1 bar and 25 °C, boosting the benchmark value by four-times. The results of equilibrium and dynamic gas adsorption measurements further indicated a remarkably high selectivity of 382 for the separation of O2/N2:21/79 mixture, demonstrating the broad potential of the MOFILS designed in this work for direct air separation. Ionic liquid ; Air separation ; Separation (statistics) ; Chemical engineering ; Gas separation ; Ionic bonding ; Chemistry ; Materials science ; Engineering ; Ion ; Membrane ; Computer science ; Organic chemistry ; Catalysis ; Oxygen Metal-Organic Frameworks: Synthesis and Applications ; Gas Sensing Nanomaterials and Sensors ; Catalytic Processes in Materials Science
Authors: Soumitra Sau | Sanmoy Karmakar | Flora Banerjee | Suman Kalyan Samanta
Source: Nanoscale (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Effect of two-fold single-atom substitutions (S, Se; C, N) in band gap engineered donor–acceptor conjugated microporous polymers on the efficient aerobic photooxidation of aryl sulfides Substitution of a single atom in a photoactive system is capable of vastly altering its optoelectronic properties leading to the generation of an efficient photocatalyst. In this study, we explore the impact of two-fold single-atom substitutions on the optoelectronic properties and photocatalytic performance of donor-acceptor type conjugated microporous polymers (D-A CMPs). For this, three isostructural triphenylamine (TPA)-based D-A CMPs were synthesized namely PTPA-BT, PTPA-BS, and PTPA-PS containing 2,1,3-benzothiadiazole, 2,1,3-benzoselenadiazole and [1,2,5]selenadiazolo[3,4-<i>c</i>]pyridine as the acceptor moieties, respectively. Firstly, PTPA-BT and PTPA-BS were synthesized using the S to Se single-atom substitution strategy, followed by the synthesis of PTPA-PS employing a second C to N single-atom substitution. The effect of single-atom substitution demonstrated drastic changes in their band gap, conductivity, and charge carrier dynamics, which in turn impacted their photocatalytic activity, although the change in their porosity was not much pronounced. In terms of photocatalytic detoxification of sulfur mustards, the activities of D-A CMPs follow the trend: PTPA-BS > PTPA-PS > PTPA-BT. In comparison with PTPA-BT (containing C, S) and PTPA-PS (containing N, Se), PTPA-BS (containing C, Se) exhibits a higher photocatalytic activity towards the photooxidation of thioanisole with >99% conversion and ∼93% isolated yield under visible-light illumination, which is attributed to its lower interfacial charge transfer resistance, stronger photocurrent response, optimal band gap and higher activity to generate superoxide anion radicals. Therefore, the two-fold single-atom substitution strategy is crucial for optimizing D-A CMPs for the photocatalytic oxidation of aryl sulfides. This approach allows fine-tuning of the optoelectronic properties to enhance photocatalytic efficiency and performance. Aryl ; Conjugated system ; Conjugated microporous polymer ; Microporous material ; Acceptor ; Polymer ; Atom (system on chip) ; Materials science ; Chemistry ; Photochemistry ; Band gap ; Combinatorial chemistry ; Polymer chemistry ; Organic chemistry ; Optoelectronics Covalent Organic Framework Applications ; Advanced Photocatalysis Techniques ; Perovskite Materials and Applications
Authors: Botan Li | Wandi Shi | Jiyuan Du | Yiyi Zhang | Haibo Zhang | Hengyu Yang | Lin Sun | Yiquan Zhang | Mingxue Li
Source: Inorganic Chemistry (article, 2024-08-05)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Structures and Single-Molecule Magnet Behavior of Dy<sub>3</sub> and Dy<sub>4</sub> Clusters Constructed by Different Dysprosium(III) Salts Using the Schiff base ligand H<sub>2</sub>L-pyra (<i>N</i>'-(2-hydroxybenzoyl)pyrazine-2-carbohydrazonamide) with multiple dentate sites, the trinuclear Dy<sup>III</sup>-based complex [Dy<sub>3</sub>(HL-pyra)<sub>2</sub>(L-pyra)<sub>2</sub>(CH<sub>3</sub>COO)<sub>3</sub>]·2H<sub>2</sub>O (<b>1</b>) was synthesized. By analyzing the fragmented assembly process and fine-tuning the bridging anions, complex [Dy<sub>4</sub>(HL-pyra)<sub>2</sub>(L-pyra)<sub>4</sub>(NO<sub>3</sub>)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]·8H<sub>2</sub>O (<b>2</b>) with different nuclear numbers was successfully synthesized. Magnetic studies demonstrated that <b>1</b> did not exhibit magnetic relaxation behavior under the external field; however, <b>2</b> exhibited zero-field single-molecule magnetic relaxation behavior with an effective energy barrier (<i>U</i><sub>eff</sub>) of 197.44 K. This is attributed to the improved anisotropy of the single ion after the normalization of the crystal structure, thus realizing the molecular magnetic switching. Moreover, magnetic dilution analysis of <b>2</b> demonstrated that the weak magnetic interaction between metal ions inhibited the occurrence of quantum tunneling of magnetization (QTM), resulting in high-performance single-molecule magnet (SMM) behavior. The reasons for the magnetic difference between these two complexes were analyzed using <i>ab initio</i> calculation and magneto-structural correlations. This study provides a reasonable prediction of the ideal configuration of the approximately parallelogram Dy<sup>III</sup>-based SMMs, thus offering an effective approach for synthesizing Dy<sub>4</sub> complexes with excellent properties. Dysprosium ; Chemistry ; Single-molecule magnet ; Magnet ; Crystallography ; Molecule ; Lanthanide ; Inorganic chemistry ; Ion ; Magnetization ; Organic chemistry ; Magnetic field Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes ; Organic and Molecular Conductors Research
Authors: Annika Lehmann | Joshua D. Queen | Christopher J. Roberts | Kari Rissanen | Heikki M. Tuononen | Philip P. Power
Source: Angewandte Chemie International Edition (article, 2024-08-19)
Field: Chemistry — Organic Chemistry

The Dialuminene Ar<sup>iPr8</sup>AlAlAr<sup>iPr8</sup> (Ar<sup>iPr8</sup>=C<sub>6</sub>H‐2,6‐(C<sub>6</sub>H<sub>2</sub>‐2,4,6‐<sup>i</sup>Pr<sub>3</sub>)<sub>2</sub>‐3,5‐<sup>i</sup>Pr<sub>2</sub>) Careful analysis of the crystals formed in the reduction of Ar<sup>iPr8</sup>AlI<sub>2</sub> (Ar<sup>iPr8</sup>=C<sub>6</sub>H-2,6-(C<sub>6</sub>H<sub>2</sub>-2,4,6-<sup>i</sup>Pr<sub>3</sub>)<sub>2</sub>-3,5-<sup>i</sup>Pr<sub>2</sub>) with sodium on sodium chloride showed them to contain the long sought-after dialuminene Ar<sup>iPr8</sup>AlAlAr<sup>iPr8</sup> (1) that forms alongside the previously characterized alanediyl :AlAr<sup>iPr8</sup>. The single crystal X-ray structure of 1 revealed a nearly planar, trans-bent C(ipso)AlAlC(ipso) core with an Al-Al distance of 2.648(2) Å. The molecular and electronic structure of 1 are consistent with an Al-Al double dative interaction augmented with diradical character and stabilized by dispersion interactions. Density functional theory calculations showed that the reactivity of :AlAr<sup>iPr8</sup> with dihydrogen involves 1, not :AlAr<sup>iPr8</sup>, as the reactive species. In contrast, the reaction of :AlAr<sup>iPr8</sup> with ethylene gave two products, the 1,4-dialuminacyclohexane Ar<sup>iPr8</sup>Al(C<sub>2</sub>H<sub>4</sub>)<sub>2</sub>AlAr<sup>iPr8</sup> (2) and the aluminacyclopentane Ar<sup>iPr8</sup>Al(C<sub>4</sub>H<sub>8</sub>) (3), that can both form from the aluminacyclopropane intermediate Ar<sup>iPr8</sup>Al(C<sub>2</sub>H<sub>4</sub>). Although the [2+2+2] cycloaddition of 1 with two equivalents of ethylene was also calculated to be exergonic, it is likely to be kinetically blocked by the numerous isopropyl substituents surrounding the Al-Al bond. Attempts to fine-tune the steric bulk of the terphenyl ligand to allow stronger Al-Al bonding were unsuccessful, leading to the isolation of the sodium salt of a cyclotrialuminene, Na<sub>2</sub>[AlAr<sup>iPr6</sup>]<sub>3</sub> (4), instead of Ar<sup>iPr6</sup>AlAlAr<sup>iPr6</sup>. Diradical ; Exergonic reaction ; Chemistry ; Steric effects ; Crystallography ; Reactivity (psychology) ; Density functional theory ; Ethylene ; Cycloaddition ; Salt metathesis reaction ; Stereochemistry ; Computational chemistry ; Metathesis ; Polymerization ; Organic chemistry ; Singlet state ; Catalysis Organometallic Complex Synthesis and Catalysis ; Synthesis and characterization of novel inorganic/organometallic compounds ; Ferrocene Chemistry and Applications
Authors: Pradeep Kumar Panda | Tsung-Pin Tasi | Min-Wei Wu | Pranjyan Dash | Chien‐Te Hsieh | Po‐Chih Yang | Jeng‐Kuei Chang
Source: Progress in Organic Coatings (article, 2024-06-27)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Development of carbon composite coatings for fire retardancy and electromagnetic interference shielding Materials science ; Electromagnetic shielding ; Composite material ; Composite number ; Electromagnetic interference ; Carbon fibers Electromagnetic wave absorption materials ; Flame retardant materials and properties ; Fiber-reinforced polymer composites
Authors: Roshan Joseph Mathew | Parvathy Radhakrishnan | R. Pragash | Joseph John | K. V. Arun Kumar | U. S. Sajeev
Source: ChemistrySelect (article, 2024-01-18)
Field: Materials Science — Polymers and Plastics

The synergistic impact of multi walled carbon nanotubes on microstructural, morphological, and optical properties of polyaniline films Abstract Nanocomposite of polyaniline (PANI) and multi walled carbon nanotube (MWCNT) was synthesised by ex‐situ solution mixing process in the N‐Methyl‐2‐Pyrrolidinone (NMP) solvent medium by varying the concentration of MWCNT in the PANI matrix. PANI‐MWCNT composite films were prepared by the drop casting method. The morphology, structure and chemical composition of PANI and PANI‐MWCNT nanocomposites were characterised by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x‐ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT‐IR) spectra. The experimental findings suggested a favourable synergy between PANI and MWCNTs. PANI‐MWCNT nanocomposite formed as randomly oriented nanofibrous clusters was confirmed, and the bandgap of the composites was found to be gradually decreased with the increase in concentration of MWCNT in the PANI matrix. The calculation of crystallinity index, crystallite size, average d ‐spacing, dislocation density, lattice strain, and inter chain separation of the samples were conducted by XRD analysis. When the MWCNT concentration increased from 0.05 % w/v to 0.5 % w/v, a rise in the degree of crystallinity from 3.39 % to 52.46 %, dislocation density from 0.03315×10 −3 (nm −2 )to 0.07133×10 −3 (nm −2 ) and lattice strain from 8.6821×10 −3 to 12.9843×10 −3 , accompanied by a reduction in both crystallite size and inter‐chain separation were observed .The microcrystalline behaviour and crystalline orientation of the PANI‐MWCNT composites were correlated with the bandgap studies. The composite formation improved the thermal stability of PANI. The co‐relation between the crystallinity parameters and fine tuning of optical bandgap and the control over the defect levels were done in this study. This synergy suggests that these composites are suitable candidates for linear and nonlinear optical (NLO) applications. Materials science ; Crystallinity ; Nanocomposite ; Polyaniline ; Crystallite ; Carbon nanotube ; Scanning electron microscope ; Composite material ; Fourier transform infrared spectroscopy ; Thermal stability ; Composite number ; Chemical engineering ; Polymer Conducting polymers and applications ; Advanced Sensor and Energy Harvesting Materials ; Supercapacitor Materials and Fabrication
Authors: Weiwei Zhang | Shibo Li | Shukai Fan | Xuejin Zhang | Xiachen Fan | Guoping Bei
Source: Journal of Advanced Ceramics (article, 2024-08-05)
Field: Materials Science — Materials Chemistry

Ti <sub>3</sub>AlC <sub>2− <i>y</i> </sub>N <sub> <i>y</i> </sub> carbonitride MAX phase solid solutions with tunable mechanical, thermal, and electrical properties Changing N content in Ti<sub>3</sub>AlC<sub>2-y</sub>N<sub>y</sub> MAX phase solid solutions allows for fine-tuning of their properties. However, systematic studies on the synthesis and properties of Ti<sub>3</sub>AlC<sub>2-y</sub>N<sub>y</sub> solid solution bulks have not been reported so far. Here, previously unreported Ti<sub>3</sub>AlC<sub>2-y</sub>N<sub>y</sub> solid solution bulks (y=0.3, 0.5, 0.8, and 1.0) were synthesized by hot pressing of their powder counterparts under optimized conditions. The prepared Ti<sub>3</sub>AlC<sub>2-y</sub>N<sub>y </sub>bulks are dense and have a fine microstructure with grain sizes of 6-8 μm. The influence of N content on the mechanical properties, electrical conductivities, and coefficients of thermal expansion (CTEs) of the prepared Ti<sub>3</sub>AlC<sub>2-y</sub>N<sub>y</sub> bulks has been clarified. Flexural strength and Vickers hardness values increased with increasing N contents, suggesting that solid solution strengthening is effective in improving the mechanical properties of Ti<sub>3</sub>AlC<sub>2-y</sub>N<sub>y</sub>. Ti<sub>3</sub>AlCN (y=1) showed the highest Vickers hardness and flexural strength among the studied samples, reaching 5.54 GPa and 550 MPa, respectively. However, the electrical conductivity and CTEs of Ti<sub>3</sub>AlC<sub>2-y</sub>N<sub>y</sub> solid solutions decreased with increasing N content, from 8.93´10<sup>-6</sup> K<sup>-1</sup> to 7.69 ´10<sup>-6</sup> K<sup>-1</sup>，and 1.33´10<sup>6</sup> S/m to 0.95´10<sup>6</sup> S/m, respectively. This work demonstrates the tunable properties of Ti<sub>3</sub>AlC<sub>2-y</sub>N<sub>y</sub> solid solutions with varying N contents, and also widens the member of MAX phase family for fundamental studies and applications. Materials science ; Vickers hardness test ; Solid solution ; Flexural strength ; Microstructure ; Hot pressing ; Phase (matter) ; Analytical Chemistry (journal) ; Thermal expansion ; MAX phases ; Grain size ; Electrical resistivity and conductivity ; Composite material ; Metallurgy ; Ceramic ; Physics MXene and MAX Phase Materials ; Aluminum Alloys Composites Properties ; Advanced ceramic materials synthesis
Authors: Fahimeh Hooriabad Saboor | Shadab Shahsavari | Mahshid Zandjou | Mehrdad Asgari
Source: ChemNanoMat (article, 2024-06-18)
Field: Chemistry — Inorganic Chemistry

From Structure to Catalysis: Advances in Metal‐Organic Frameworks‐Based Shape‐Selective Reactions Abstract The presence of shape‐ and size‐selective catalysts in various catalytic reactions is of paramount importance. Metal‐organic frameworks (MOFs) possess a distinctive characteristic of lacking in‐accessible dead spaces, owing to their well‐structured nature. The effective separation of active sites within MOFs is facilitated by their exceptionally high surface area, which allows for a high density of active sites per unit volume of the catalyst. In this comprehensive review article, we delve into one of the most critical and practical features of MOFs: their ability to modify and engineer the structure of these materials. This structural engineering approach enables the attainment of desired physical, chemical, and surface properties, particularly in the realm of heterogeneous catalysts. The article encompasses several key areas, including surface functionalization within MOFs, synthesis of novel enzyme‐inspired MOFs, creation of mesoporous MOFs, development of porous structures utilizing MOFs, and engineering of structural limitations in MOFs. These rapidly advancing and highly applicable topics, especially in the field of heterogeneous catalysts, are thoroughly investigated and analyzed within the purview of this comprehensive review article. Catalysis ; Metal-organic framework ; Metal ; Chemistry ; Nanotechnology ; Materials science ; Chemical engineering ; Organic chemistry ; Engineering Metal-Organic Frameworks: Synthesis and Applications ; Covalent Organic Framework Applications ; Polyoxometalates: Synthesis and Applications
Authors: Fredrik Heen Blindheim | Kristin Syverud | Jost Ruwoldt
Source: Energy & Fuels (article, 2024-02-01)
Field: Chemistry — Analytical Chemistry

Lignin-Based Wax Inhibitors This article tested a novel concept for synthesizing green wax inhibitors. Four technical lignins were reacted with stearoyl chloride to produce esterified C18 esterified lignin. The effect of the reaction on the lignin molecular weight, characteristic FTIR spectra, and thermal degradation was surveyed. In addition, wax inhibition testing was performed by rheology on model waxy oils. The grafting reactions increased the mass-average molecular weight of the lignin and in some cases also the polydispersity index. FTIR analysis confirmed the success of esterification reactions as the O–H stretching band decreased, whereas the C–H and C═O stretching bands significantly increased. The thermal degradation was further found to occur at temperatures above 170 °C, indicating that the lignin wax inhibitors were thermally stable enough for crude oil production. The effect on waxy gelation was varied, showing that the low molecular weight waxes benefited more than the high molecular ones. A gelation point reduction of up to 6 °C was found after lignin addition. After the wax type, wax concentration, lignin concentration, and lignin type were varied, it was found that C18 esterified Kraft lignin exhibited the most beneficial effect. The results from viscometry agreed with the observations from the rheometric gelation point. Cross-polarized microscopy was used to map the effect on the wax crystal morphology. A difference was found only in the case of one esterified Kraft lignin, which yielded smaller and more finely dispersed wax crystals. In conclusion, a new wax inhibitor was synthesized by reacting technical lignin with stearoyl chloride. This lignin showed wax inhibitor activity in some of the tested cases. At this point, the length of the pendant alkyl chains (C18) is likely a limiting factor. However, this study attributes the potential for a new concept to synthesize green wax inhibitors. Wax ; Lignin ; Dispersity ; Chemistry ; Fourier transform infrared spectroscopy ; Viscometer ; Organic chemistry ; Kraft paper ; Molar mass distribution ; Nuclear chemistry ; Chemical engineering ; Materials science ; Viscosity ; Polymer ; Composite material Petroleum Processing and Analysis ; Lignin and Wood Chemistry ; Enhanced Oil Recovery Techniques
Authors: Koh Sugamata
Source: Chemistry - A European Journal (review, 2024-12-10)
Field: Chemistry — Inorganic Chemistry

Hydroxamate‐Based Metal‐Organic Frameworks This mini-review focuses on recent developments in hydroxamate-based metal-organic frameworks (MOFs), which exhibit unique structures and properties distinct from those of carboxylate-based MOFs. Hydroxamates (RCONHO<sup>-</sup>) form MOFs with novel structural motifs and functionalities. In this review, synthetic strategies, structural characteristics, and functional applications of key examples of hydroxamate-based MOFs are described, providing insights into the influence of the hydroxamate ligand on the MOF properties compared to that of the carboxylate-based analogues. Carboxylate ; Metal-organic framework ; Ligand (biochemistry) ; Combinatorial chemistry ; Chemistry ; Metal ; Organic chemistry ; Biochemistry Metal-Organic Frameworks: Synthesis and Applications ; Magnetism in coordination complexes ; Metal complexes synthesis and properties