jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Ko Kuwamoto | Masaya Okamura | Shiro Hikichi
Source: ChemistryEurope (article, 2024-01-10)
Field: Materials Science — Materials Chemistry

Switching Product Selectivity in Immobilized Tungstate Catalysts by Control of Hydrophobicity of Mesoporous Silicate Supports Abstract Novel mesoporous silicates modified with imidazolium cation were applied as the support for peroxotungstate. Stepwise introduction of multiple functional groups to SBA‐15 was achieved by the combination of the direct and post‐synthesis procedures. The co‐condensation of tetraethoxysilane and 3‐(imidazolyl‐1‐yl)‐propyltriethoxysilane in the presence of the micelles of an amphiphilic surfactant yields the hydrophilic SBA‐15 type silicate support with the imidazole modifier locating into the mesopores. The hydrophobic environment of the supports was imparted by capping the residual silanols on the silicate surface with trimethylsilyl groups. The fluoroalkyl‐ or alkyl‐imidazolium cation‐anchored supports were derived from the corresponding imidazole‐functionalized precursors. The anion‐exchanging reaction between peroxytungstate and the imidazolium cation‐anchored supports yielded the corresponding tungstate‐immobilized catalysts. The hydrophilic catalyst with the fluoroalkyl‐imidazolium mediated alkene epoxidation with H 2 O 2 in less polar solvents. The hydrophobic one, in contrast, produced diol through the epoxidation and following hydration in an aqueous solvent by the action of the highly Lewis acidic tungsten. The hydrophobic catalysts had the advantage of being more tolerant than hydrophilic catalysts, as evidenced by reusability tests. The activities of the alkyl‐imidazolium catalysts were lower than those of the corresponding fluoroalkyl‐imidazolium catalysts, indicating that the local structures surrounding the tungstate site affected the catalytic performance. Catalysis ; Tungstate ; Chemistry ; Alkyl ; Mesoporous material ; Selectivity ; Micelle ; Amphiphile ; Alkene ; Imidazole ; Mesoporous silica ; Heterogeneous catalysis ; Aqueous solution ; Inorganic chemistry ; Organic chemistry ; Polymer chemistry ; Copolymer ; Polymer Mesoporous Materials and Catalysis ; Polyoxometalates: Synthesis and Applications ; Layered Double Hydroxides Synthesis and Applications
Authors: Jonathan G. Coldstream | Philip J. Camp | D. Phillips | Peter J. Dowding
Source: The Journal of Chemical Physics (article, 2024-02-06)
Field: Chemistry — Organic Chemistry

Polymeric surfactants at liquid–liquid interfaces: Dependence of structural and thermodynamic properties on copolymer architecture Polymeric surfactants are amphiphilic molecules with two or more different types of monomers. If one type of monomer interacts favorably with a liquid, and another type of monomer interacts favorably with another, immiscible liquid, then polymeric surfactants adsorb at the interface between the two liquids and reduce the interfacial tension. The effects of polymer architecture on the structural and thermodynamic properties of the liquid-liquid interface are studied using molecular simulations. The interface is modeled with a non-additive binary Lennard-Jones fluid in the two-phase region of the phase diagram. Block and gradient copolymer surfactants are represented with coarse-grained, bead-spring models, where each component of the polymer favors one or the other liquid. Gradient copolymers have a greater concentration at the interface than do block copolymers because the gradient copolymers adopt conformations partially aligned with the interface. The interfacial tension is determined as a function of the surface excess of polymeric surfactant. Gradient copolymers are more potent surfactants than block copolymers because the gradient copolymers cross the dividing surface multiple times, effectively acting as multiple individual surfactants. For a given surface excess, the interfacial tension decreases monotonically when changing from a block to a gradient architecture. The coarse-grained simulations are complemented by all-atom simulations of acrylic-acid/styrene copolymers at the chloroform-water interface, which have been studied in experiments. The agreement between the simulations (both coarse-grained and atomistic) and experiments is shown to be excellent, and the molecular-scale structures identified in the simulations help explain the variation of surfactancy with copolymer architecture. Copolymer ; Materials science ; Surface tension ; Polymer ; Monomer ; Adsorption ; Phase diagram ; Polymer chemistry ; Amphiphile ; Phase (matter) ; Chemical engineering ; Styrene ; Thermodynamics ; Chemistry ; Physical chemistry ; Composite material ; Organic chemistry Surfactants and Colloidal Systems ; Enhanced Oil Recovery Techniques ; Block Copolymer Self-Assembly
Authors: Borna Pielić | Matko Mužević | Dino Novko | Jiaqi Cai | A Bremerich | Robin Ohmann | Marko Kralj | Iva Šrut Rakić | Carsten Busse
Source: npj 2D Materials and Applications (article, 2024-09-12)
Field: Materials Science — Materials Chemistry

Probing the interplay of interactions, screening and strain in monolayer MoS2 via self-intercalation Abstract Controlling many-body interactions in two-dimensional systems remains a formidable task from the perspective of both fundamental physics and application. Here, we explore remarkable electronic structure alterations of MoS 2 monolayer islands on graphene on Ir(111) induced by non-invasive self-intercalation. This introduces significant differences in morphology and strain of MoS 2 as a result of the modified interaction with the substrate. Consequently, considerable changes of the band gap and non-rigid electronic shifts of valleys are detected, which are a combined effect of the screening of the many-body interactions and strain in MoS 2 . Furthermore, theory shows that each substrate leaves a unique stamp on the electronic structure of two-dimensional material in terms of those two parameters, restricted by their correlation. Monolayer ; Intercalation (chemistry) ; Substrate (aquarium) ; Strain (injury) ; Graphene ; Chemical physics ; Nanotechnology ; Materials science ; Condensed matter physics ; Band gap ; Electronic structure ; Chemistry ; Physics ; Optoelectronics ; Inorganic chemistry ; Biology 2D Materials and Applications ; Graphene research and applications ; Electronic and Structural Properties of Oxides
Authors: Giuseppe Tartaro | Davide Schirone | Luigi Gentile | Gerardo Palazzo
Source: Journal of Surfactants and Detergents (article, 2024-12-17)
Field: Chemistry — Organic Chemistry

Microstructure of sulfosuccinates based microemulsions Abstract The system made by water, isooctane and a blend of Sodium dioctyl sulfosuccinate (AOT) with its more hydrophilic homologue sodium dihexyl sulfosuccinate (SDHS) can give raise to Winsor I, III and II equilibria at room temperature by slight changes in salinity. The phase transitions have been tracked using diffusion NMR, and solubilized volume fractions while small‐angle X‐ray scattering (SAXS) provided insight into the characteristic lengths (ξ) within the microemulsions' structures. Our findings reveal a peculiar linear correlation between the reciprocal of these characteristic lengths (ξ −1 ) and the HLD values. For HLD &lt;0, ξ −1 decreases linearly with HLD with a slope = −0.0056 Å −1 but just above HLD = 0 the slope reverses (+0.0056 Å −1 ) and ξ −1 increases linearly with HLD demonstrating that the HLD reflects the direction of interfacial curvature. However, at the optimal composition where the curvature is null and HLD = 0, the linear trends observed for ξ −1 below and above HLD = 0 converge at a ξ −1 value that is significantly greater than 0. This indicates that HLD is a measure of the interface/volume ratio and not of the interface curvature. This work aims to deepen the understanding of the relationship between the semi‐empirical HLD equation and the spontaneous curvature of microemulsions. Microemulsion ; Chemistry ; Curvature ; Small-angle X-ray scattering ; Phase (matter) ; Sodium ; Microstructure ; Thermodynamics ; Scattering ; Analytical Chemistry (journal) ; Crystallography ; Chromatography ; Organic chemistry ; Mathematics ; Geometry ; Optics ; Physics Surfactants and Colloidal Systems ; NMR spectroscopy and applications ; Material Dynamics and Properties
Authors: Jing Zhang | Liyuan Zhao | Ai‐Xin Liang | Xueyan Geng | Mengmeng Hou | Haojie Cheng | Shouren Zhang | Baocheng Yang | Junbo Li | Jian Chen
Source: Journal of Nanobiotechnology (article, 2024-12-20)
Field: Materials Science — Materials Chemistry

Resistant starch grafted cerium-sulfasalazine infinite coordination polymers synergistically remold intestinal metabolic microenvironment for inflammatory bowel disease therapy Inflammatory bowel disease (IBD) is a chronic gastrointestinal disease which is closely related with the overproduced reactive oxygen species (ROS), increased pro-inflammatory cytokines and disordered intestinal microbes. However, current therapeutic methods usually ignored the interrelation among the pathogenesis, and mainly focused on a single factor, inducing clinical outcomes unsatisfied. Herein, biocompatible infinite coordination polymers of drugs (Ce-SASP-RS ICPs) composed of Ce ions, FDA-approved drug sulfasalazine (SASP) and natural ingredient resistant starch (RS) were developed for synergistic treatment of IBD. The proper Ce<sup>3+</sup>/Ce<sup>4+</sup> ratio in Ce-SASP-RS ICPs can endow them with SOD-like activities, POD-like activities and •OH scavenging ability, which guarantee Ce-SASP-RS ICPs to simultaneously kill bacteria and maintain ROS balance through cascade reactions. Owing to the recovered redox balance microenvironment, SASP in Ce-SASP-RS ICPs can better play their anti-inflammatory function. Moreover, benefitting from the recovered metabolic balance of ROS and inflammatory cytokines in colon, resistant starch can also function better in modifying gut microbiota through generating short-chain fatty acids. Collectively, Ce-SASP-RS ICPs can synergistically restore intestinal metabolic microenvironment through modulating redox balance, attenuating inflammation and modifying intestinal flora. Hence, in view of the mutual influences among IBD pathogenesis, this work presents a synergistic intervention approach for effectively treating IBD. Sulfasalazine ; Inflammatory bowel disease ; Cerium ; Chemistry ; Metabolic disease ; Pharmacology ; Internal medicine ; Disease ; Medicine ; Inorganic chemistry Advanced Nanomaterials in Catalysis ; Nanoparticle-Based Drug Delivery ; Nanomaterials for catalytic reactions
Authors: Ibrahim S. Al Nasr | Waleed S. Koko | Tariq A. Khan | Rainer Schobert | Bernhard Biersack
Source: Antibiotics (article, 2024-11-22)
Field: Chemistry — Organic Chemistry

Antiparasitic Activities of Acyl Hydrazones from Cinnamaldehydes and Structurally Related Fragrances <b>Background:</b> New drugs for the treatment of protozoal parasite infections such as toxoplasmosis and leishmaniasis are required. Cinnamaldehyde and its derivatives appear to be promising antiparasitic drug candidates. <b>Methods:</b> Acyl hydrazones of cinnamaldehyde, 4-dimethylaminocinnamaldehyde, and of the synthetic fragrances silvial<sup>TM</sup> and florhydral<sup>TM</sup> were prepared and tested for activity against <i>Toxoplasma gondii</i> (<i>T. gondii</i>) and <i>Leishmania major</i> (<i>L. major</i>) parasites. <b>Results:</b> Three cinnamaldehyde acyl hydrazones (3-hydroxy-2-naphthoyl <b>2a</b> and the salicyloyls <b>2c</b> and <b>2d</b>) showed good activity against <i>T. gondii</i>, and two compounds derived from cinnamaldehyde and florhydral<sup>TM</sup> (3-hydroxy-2-naphthoyls <b>2a</b> and <b>4a</b>) exhibited moderate activity against <i>L. major</i> promastigotes. <b>Conclusions:</b> In particular, the identified antitoxoplasmal activities are promising and might lead to the development of new potent and cost-effective drug candidates for the therapy of toxoplasmosis. Cinnamaldehyde ; Toxoplasma gondii ; Antiparasitic ; Antiparasitic agent ; Eugenol ; Toxoplasmosis ; Drug ; Chemistry ; Pharmacology ; Microbiology ; Medicine ; Biology ; Virology ; Biochemistry ; Organic chemistry ; Immunology Synthesis and Biological Evaluation ; Synthesis and Characterization of Heterocyclic Compounds ; Synthesis and biological activity
Authors: Georgia I. Sakellari | Hannah Batchelor | Fotis Spyropoulos
Source: Drug Delivery (article, 2024-11-08)
Field: Materials Science — Materials Chemistry

The role of lipid particle-laden interfaces in regulating the co-delivery of two hydrophobic actives from o/w emulsions Co-delivery strategies have become an integral active delivery approach, although understanding of how the microstructural characteristics could be deployed to achieve independently regulated active co-delivery profiles, is still an area at its infancy. Herein, the capacity to provide such control was explored by utilizing Pickering emulsions stabilized by lipid particles, namely solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs). These dual functional species, regarding their concurrent Pickering stabilization and active carrying/delivery capabilities, were formulated with different solid lipid and surfactant types, and the effect on the release and co-release modulation of two hydrophobic actives separately encapsulated within the lipid particles themselves and within the emulsion droplets was investigated. Disparities between the release profiles from the particles in aqueous dispersions or at an emulsion interface, were related to the specific lipid matrix composition. Particles composed of lipids with higher oil phase compatibility of the emulsion droplets were shown to exert less control over their release regulation ability, as were particles in the presence of surfactant micelles in the continuous phase. Irrespective of their formulation characteristics, all particles provided a level of active release control from within the emulsion droplets, which was dependant on the permeability of the formed interfacial layer. Specifically, use of a bulkier particle surfactant or particle sintering at the droplet interface resulted in more sustained droplet release rates. Compared to sole release, the co-release performance remained unaffected by the co-existence of the two hydrophobic actives with the co-release behavior persisting over a storage period of 1 month. Emulsion ; Pulmonary surfactant ; Chemical engineering ; Pickering emulsion ; Materials science ; Particle size ; Amphiphile ; Micelle ; Aqueous two-phase system ; Particle (ecology) ; Nanoparticle ; Controlled release ; Phase (matter) ; Biophysics ; Nanotechnology ; Aqueous solution ; Chemistry ; Organic chemistry ; Copolymer ; Polymer ; Composite material Pickering emulsions and particle stabilization ; Proteins in Food Systems ; Advancements in Transdermal Drug Delivery
Authors: Katherine W. Rush | Katherine B. Alwan | A. Tamar Conner | Evan F. Welch | Ninian J. Blackburn
Source: Inorganic Chemistry (article, 2024-10-30)
Field: Chemistry — Inorganic Chemistry

Mechanisms of Copper Selectivity and Release by the Metallochaperone CusF: Insights from CO-Binding, Rapid-Freeze-Quench EXAFS, and Unnatural Amino Acid Substitution Metallochaperones are small proteins that shuttle essential metal ions such as Cu selectively to their cellular targets. CusF has unusual Cu(I) coordination, bound by two methionines, one histidine and a capping tryptophan residue, W44. Here we compare the CO binding reactivity of the wild type (WT) protein and its W44A, F, and M variants. Fourier-transform infrared (FTIR) indicates that W44A provides unhindered access for CO, while W44M is unreactive. WT is also largely unreactive to CO suggesting that the tryptophan cap is effective in shielding the Cu(I) center from exogenous adduct formation, while the Phe variant shows partial reactivity suggestive of an equilibrium between cap-on and cap-off conformers. Rates of metal transfer to the partner CusB are consistent with the π-cation cap providing both selectivity and redox protection. Unnatural amino acid substitutions of the W44 ligand with cyano-Phe and Br-Phe underpin the conclusion that the Phe ligand is a less effective capping residue. Finally, density functional theory (DFT) calculations validate the CO-binding strategy. Overall, the study suggests that CusF uses the tryptophan cap to protect against exogenous ligand (O<sub>2</sub>) attack while the mechanism of protein-protein complex formation allows the cap to swing out of the way, and thus have minimal effect on the rates of metal transfer. Chemistry ; Copper ; Extended X-ray absorption fine structure ; Selectivity ; Substitution (logic) ; Crystallography ; Amino acid ; Stereochemistry ; Biochemistry ; Organic chemistry ; Absorption spectroscopy ; Catalysis Metal-Organic Frameworks: Synthesis and Applications ; Crystallography and molecular interactions ; CO2 Reduction Techniques and Catalysts
Authors: Khalid Zouhri | Mohamed Mohamed | Kayla Nulph | Parker O. Laubie | Luke J. Snyder
Source: International Journal of Energy Research (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Solid Oxide Fuel Cell Anode Porosity and Tortuosity Effect on the Exergy Efficiency Improving the efficiency of solid oxide fuel cells (SOFCs) is critical for advancing clean energy solutions on a global scale. One major challenge in enhancing SOFC efficiency is reducing anode diffusion polarization, which can significantly hinder performance. This study addresses this issue by investigating the effects of anode tortuosity and porosity on the exergy efficiency of SOFCs. The novelty of this research lies in its comprehensive numerical model, which uniquely incorporates detailed material properties and their impact on SOFC performance—specifically focusing on anode tortuosity and porosity. Using advanced Multiphysics software, we developed a model that solves mass, electron transfer, and energy equations discretized via the finite differences method. The study meticulously examines how variations in these parameters influence SOFC efficiency, providing new insights into optimal anode design. Our methodology involves simulating different anode configurations to pinpoint the key parameters that affect exergy efficiency, thereby minimizing the experimental costs and time associated with traditional approaches. The quantitative results of this study are significant. We found that an anode tortuosity of 5.5 and a porosity range of 0.05–0.1 optimize exergy efficiency, achieving a 15% improvement compared to conventional designs. Additionally, a mean pore radius between 15 and 20 µ m was identified as optimal for enhancing cell voltage. These findings elucidate the critical relationship between anode material properties and SOFC performance, offering a practical pathway to improving efficiency. This research provides a novel numerical approach to understanding and optimizing anode characteristics in SOFCs. By highlighting the importance of specific material properties, such as tortuosity and porosity, and demonstrating their impact on exergy efficiency, this study offers valuable guidance for future SOFC design and development. Tortuosity ; Porosity ; Anode ; Solid oxide fuel cell ; Oxide ; Materials science ; Exergy ; Fuel cells ; Chemical engineering ; Waste management ; Chemistry ; Composite material ; Metallurgy ; Electrode ; Engineering Advancements in Solid Oxide Fuel Cells ; Fuel Cells and Related Materials ; Electrocatalysts for Energy Conversion
Authors: Bryce G. Mullens | Frederick P. Marlton | Matilde Saura‐Múzquiz | Michelle Everett | Cheng Li | Alicia Manjón‐Sanz | Matthew G. Tucker | Frédéric Poineau | James Louis–Jean | Supratik Mukherjee | Subrata Mondal | G. Vaitheeswaran | Brendan J. Kennedy
Source: Physical Chemistry Chemical Physics (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Toxic, radioactive, and disordered: a total scattering study of TlTcO<sub>4</sub> A detailed variable temperature neutron total scattering study of the potential nuclear waste matrix TlTcO<sub>4</sub> was conducted. The long-range average structure of TlTcO<sub>4</sub> undergoes an orthorhombic <i>Pnma</i> to tetragonal <i>I</i>4<sub>1</sub>/<i>amd</i> phase transition below 600 K, consistent with previous synchrotron X-ray diffraction studies. However, several anomalies were observed in the Rietveld refinements to the neutron powder diffraction data, such as large atomic displacement parameters at low temperature and a shortening of the Tc-O bond distance upon heating. Modelling the short-range local structure of both the low- and high-temperature data required a lowering of symmetry to the monoclinic <i>P</i>2<sub>1</sub>/<i>c</i> model due to the stereochemical activity of the Tl<sup>+</sup> 6s<sup>2</sup> lone pairs. Density functional theory calculations also verified this model to have a lower ground state energy than the corresponding long-range average structure. It is concluded that at low temperatures, the Tl<sup>+</sup> 6s<sup>2</sup> lone pairs are 'frozen' into the structure. Upon heating, the rigid TcO<sub>4</sub> tetrahedra begin to rotate, as governed by the Γ<sub>3</sub><sup>+</sup> and M<sub>4</sub><sup>+</sup> modes. However, there is a disconnect between the two length scales, with the 6s<sup>2</sup> lone pair electrons remaining stereochemically active on the local scale, as observed in the neutron pair distribution function fits. The orthorhombic <i>Pnma</i> to tetragonal <i>I</i>4<sub>1</sub>/<i>amd</i> phase transition is seemingly the result of a change in the correlation length of the Tl<sup>+</sup> 6s<sup>2</sup> lone pairs, leading to a larger unit cell volume due to their uncorrelated displacements. Scattering ; Materials science ; Radiochemistry ; Physics ; Chemistry ; Nuclear physics ; Optics Nuclear materials and radiation effects ; Luminescence Properties of Advanced Materials ; Crystal Structures and Properties
Authors: Jakub Antala | Jiří Schulz | Ivana Cı́sařová | Petr Štěpnička
Source: New Journal of Chemistry (article, 2024-01-01)
Field: Chemistry — Inorganic Chemistry

Synthesis, reactivity and coordination behaviour of a ferrocene phosphinostibine and intramolecular interactions in its P(<scp>v</scp>) and Sb(<scp>v</scp>) derivatives A ferrocene phosphinostibine equipped with different substituents at the P and Sb atoms coordinates as a typical hybrid ligand. Manipulation of the pnictogen substituents in its molecule results in intramolecular P → Sb donor–acceptor interactions. Chemistry ; Intramolecular force ; Ferrocene ; Pnictogen ; Reactivity (psychology) ; Stereochemistry ; Ligand (biochemistry) ; Acceptor ; Molecule ; Medicinal chemistry ; Organic chemistry ; Receptor ; Electrochemistry ; Physical chemistry Synthesis and characterization of novel inorganic/organometallic compounds ; Ferrocene Chemistry and Applications ; Organometallic Complex Synthesis and Catalysis
Authors: Fatemeh Barzegar | Marzieh Kamankesh | Abdorreza Mohammadi
Source: Phytochemical Analysis (article, 2024-07-19)
Field: Chemistry — Analytical Chemistry

An efficient microchip electromembrane extraction online with high‐performance liquid chromatography for the measurement of nicotine in high consumption vegetables Selective electromembrane extraction of nicotine from the donor phase to the acceptor phase was performed by optimizing the main variables influencing the method mechanism. The new channel design in this analytical system and online injection increased efficiency, stability, and repeatability. The results revealed that this method is capable for the efficient determination of trace amount of nicotine in edible vegetables. Chemistry ; Chromatography ; Repeatability ; High-performance liquid chromatography ; Nicotine ; Extraction (chemistry) ; Detection limit Analytical chemistry methods development ; Advanced Chemical Sensor Technologies ; Electrochemical Analysis and Applications