jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Tomáš Hrivnák | Miroslav Medveď | Wojciech Bartkowiak | Robert Zaleśny
Source: Molecules (article, 2022-12-09)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Hyperpolarizabilities of Push–Pull Chromophores in Solution: Interplay between Electronic and Vibrational Contributions Contemporary design of new organic non-linear optical (NLO) materials relies to a large extent on the understanding of molecular and electronic structure-property relationships revealed during the years by available computational approaches. The progress in theory-hand-in-hand with experiment-has enabled us to identify and analyze various physical aspects affecting the NLO responses, such as the environmental effects, molecular vibrations, frequency dispersion, and system dynamics. Although it is nowadays possible to reliably address these effects separately, the studies analyzing their mutual interplay are still very limited. Here, we employ density functional theory (DFT) methods in combination with an implicit solvent model to examine the solvent effects on the electronic and harmonic as well as anharmonic vibrational contributions to the static first hyperpolarizability of a series of push-pull α,ω-diphenylpolyene oligomers, which were experimentally shown to exhibit notable second-order NLO responses. We demonstrate that the magnitudes of both vibrational and electronic contributions being comparable in the gas phase significantly increase in solvents, and the enhancement can be, in some cases, as large as three- or even four-fold. The electrical and mechanical anharmonic contributions are not negligible but cancel each other out to a large extent. The computed dynamic solute NLO properties of the studied systems are shown to be in a fair agreement with those derived from experimentally measured electric-field-induced second-harmonic generation (EFISHG) signals. Our results substantiate the necessity to consider concomitantly both solvation and vibrational effects in modeling static NLO properties of solvated systems. Anharmonicity ; Hyperpolarizability ; Density functional theory ; Solvation ; Chromophore ; Chemical physics ; Molecular vibration ; Chemistry ; Harmonic ; Solvent effects ; Computational chemistry ; Molecular dynamics ; Molecular physics ; Statistical physics ; Physics ; Molecule ; Solvent ; Condensed matter physics ; Quantum mechanics ; Organic chemistry Nonlinear Optical Materials Research ; Photochemistry and Electron Transfer Studies ; Structural and Chemical Analysis of Organic and Inorganic Compounds
Authors: Magdaléna Hromadová | Philippe P. Lainé
Source: Current Opinion in Electrochemistry (article, 2022-04-04)
Field: Materials Science — Polymers and Plastics

Recent advances in electrochemistry of pyridinium-based electrophores: A structronic approach Context (archaeology) ; Nanotechnology ; Electrochemistry ; Covalent bond ; Scope (computer science) ; Pyridinium ; Molecule ; Energy storage ; Materials science ; Molecular engineering ; Chemistry ; Computer science ; Physics ; Organic chemistry ; Electrode ; Geology Conducting polymers and applications ; Electrochemical Analysis and Applications ; Molecular Junctions and Nanostructures
Authors: Federica Valentini | Oriana Piermatti | Luigi Vaccaro
Source: Catalysts (article, 2022-12-22)
Field: Chemistry — Organic Chemistry

Metal and Metal Oxide Nanoparticles Catalyzed C–H Activation for C–O and C–X (X = Halogen, B, P, S, Se) Bond Formation The direct functionalization of an inactivated C–H bond has become an attractive approach to evolve toward step-economy, atom-efficient and environmentally sustainable processes. In this regard, the design and preparation of highly active metal nanoparticles as efficient catalysts for C–H bond activation under mild reaction conditions still continue to be investigated. This review focuses on the functionalization of un-activated C(sp3)–H, C(sp2)–H and C(sp)–H bonds exploiting metal and metal oxide nanoparticles C–H activation for C–O and C–X (X = Halogen, B, P, S, Se) bond formation, resulting in more sustainable access to industrial production. Catalysis ; Halogen ; Metal ; Surface modification ; Oxide ; Atom (system on chip) ; Chemistry ; Nanoparticle ; Materials science ; Nanotechnology ; Organic chemistry ; Physical chemistry Catalytic C–H Functionalization Methods ; Sulfur-Based Synthesis Techniques ; Synthesis and Catalytic Reactions
Authors: Petra Dunkel
Source: Encyclopedia (article, 2022-07-01)
Field: Materials Science — Materials Chemistry

Photoremovable Protecting Groups Photoremovable protecting groups (PPGs) (also often called photocages in the literature) are used for temporary inactivation of biologically active substrates. By photoirradiation the PPG could be cleaved off and the biological activity could be restored on-demand, with a high spatiotemporal precision. The on-site liberation of the biologically active substrate could be exploited for studying dynamic biological processes or for designing targeted pharmacological interventions in vitro or in vivo. Several chemical scaffolds have been described and tested as PPGs, operating at different wavelengths. The scope of potential substrates is very broad, spanning from small molecules to proteins. In a wider context, PPGs could be used for the design of various light-responsive materials as well, for diverse applications. Scope (computer science) ; Context (archaeology) ; Substrate (aquarium) ; Nanotechnology ; Biological activity ; Biochemical engineering ; Computer science ; Chemistry ; In vitro ; Materials science ; Biochemistry ; Engineering ; Biology ; Ecology Photochromic and Fluorescence Chemistry ; Nanoplatforms for cancer theranostics ; Photoreceptor and optogenetics research
Authors: Chun-Pei Shih | Xiaofang Tang | Chiung Wen Kuo | Di‐Yen Chueh | Peilin Chen
Source: Frontiers in Chemistry (review, 2022-09-23)
Field: Materials Science — Biomaterials

Design principles of bioinspired interfaces for biomedical applications in therapeutics and imaging In the past two decades, we have witnessed rapid developments in nanotechnology, especially in biomedical applications such as drug delivery, biosensing, and bioimaging. The most commonly used nanomaterials in biomedical applications are nanoparticles, which serve as carriers for various therapeutic and contrast reagents. Since nanomaterials are in direct contact with biological samples, biocompatibility is one of the most important issues for the fabrication and synthesis of nanomaterials for biomedical applications. To achieve specific recognition of biomolecules for targeted delivery and biomolecular sensing, it is common practice to engineer the surfaces of nanomaterials with recognition moieties. This mini-review summarizes different approaches for engineering the interfaces of nanomaterials to improve their biocompatibility and specific recognition properties. We also focus on design strategies that mimic biological systems such as cell membranes of red blood cells, leukocytes, platelets, cancer cells, and bacteria. Nanotechnology ; Biocompatibility ; Nanomaterials ; Drug delivery ; Nanomedicine ; Materials science ; Biocompatible material ; Nanoparticle ; Biomedical engineering ; Engineering Nanoparticle-Based Drug Delivery ; Nanoplatforms for cancer theranostics ; Advanced biosensing and bioanalysis techniques
Authors: Alicia Götz | Xiaoye Wang | Alice Ruini | Wenhao Zheng | Paniz Soltani | Robert Graf | Alexander Tries | Juan Li | Carlos‐Andres Palma | Elisa Molinari | Michael Ryan Hansen | Hai I. Wang | Deborah Prezzi | Kläus Müllen | Akimitsu Narita
Source: Journal of Materials Chemistry C (article, 2022-01-01)
Field: Materials Science — Materials Chemistry

Band structure modulation by methoxy-functionalization of graphene nanoribbons Graphene nanoribbons functionalized with methoxy groups were synthesized. Theoretical studies predicted reduced bandgap and effective mass of charge carriers. THz spectroscopy revealed ∼25% enhancement of the photoconductivity. Materials science ; Surface modification ; Graphene ; Photoconductivity ; Graphene nanoribbons ; Band gap ; Modulation (music) ; Terahertz radiation ; Charge carrier ; Optoelectronics ; Electronic band structure ; Nanotechnology ; Spectroscopy ; Chemical engineering ; Condensed matter physics Graphene research and applications ; 2D Materials and Applications ; Molecular Junctions and Nanostructures
Authors: Carla Gasbarri | Guido Angelini
Source: ARKIVOC (article, 2022-06-24)
Field: Chemistry — Organic Chemistry

An overview on the role of cyclodextrins in the synthesis of silver nanoparticles by chemical reduction The association between cyclodextrins (CDs) and silver nanoparticles (AgNPs) has been successfully exploited in a large number of applications. Generally, CDs act as stabilizers, however, their reactivity as reducing agents can be directly involved in the synthesis of AgNPs. Herein, the most recent results regarding AgNPs prepared by chemical reduction from native -, -and -cyclodextrins are reported. The behavior of CDs in host-guest inclusion complexes onto the metal surface, and the effects on the AgNPs properties have also been examined. Unlike -CD/AgNPs and -CD/AgNPs, additional reducing agents were required for the investigated -CD/AgNPs. Chemistry ; Reduction (mathematics) ; Combinatorial chemistry ; Silver nanoparticle ; Nanoparticle ; Nanotechnology ; Chemical reduction ; Physical chemistry Nanomaterials for catalytic reactions ; Nanoparticles: synthesis and applications
Authors: Gloria E. O. Borgstahl | William B. O’Dell | Martin Egli | Jan Kern | Andrey Kovalevsky | Jiao Lin | Dean A. A. Myles | Mark A. Wilson | Wen Zhang | Petrus H. Zwart | Leighton Coates
Source: Review of Scientific Instruments (article, 2022-06-01)
Field: Materials Science — Materials Chemistry

EWALD: A macromolecular diffractometer for the second target station Revealing the positions of all the atoms in large macromolecules is powerful but only possible with neutron macromolecular crystallography (NMC). Neutrons provide a sensitive and gentle probe for the direct detection of protonation states at near-physiological temperatures and clean of artifacts caused by x rays or electrons. Currently, NMC use is restricted by the requirement for large crystal volumes even at state-of-the-art instruments such as the macromolecular neutron diffractometer at the Spallation Neutron Source. EWALD's design will break the crystal volume barrier and, thus, open the door for new types of experiments, the study of grand challenge systems, and the more routine use of NMC in biology. EWALD is a single crystal diffractometer capable of collecting data from macromolecular crystals on orders of magnitude smaller than what is currently feasible. The construction of EWALD at the Second Target Station will cause a revolution in NMC by enabling key discoveries in the biological, biomedical, and bioenergy sciences. Diffractometer ; Neutron ; Macromolecule ; Crystal (programming language) ; Spallation ; Spallation Neutron Source ; Neutron scattering ; Physics ; Nanotechnology ; Materials science ; Nuclear physics ; Chemistry ; Crystallography ; Crystal structure ; Computer science Enzyme Structure and Function ; Nuclear Physics and Applications ; Metabolomics and Mass Spectrometry Studies
Authors: Yohei Miwa | Taro Udagawa | Shoichi Kutsumizu
Source: Scientific Reports (article, 2022-07-25)
Field: Materials Science — Polymers and Plastics

Repulsive segregation of fluoroalkyl side chains turns a cohesive polymer into a mechanically tough, ultrafast self-healable, nonsticky elastomer Dynamic crosslinking of flexible polymer chains via attractive and reversible interactions is widely employed to obtain autonomously self-healable elastomers. However, this design leads to a trade-off relationship between the strength and self-healing speed of the material, i.e., strong crosslinks provide a mechanically strong elastomer with slow self-healing property. To address this issue, we report an "inversion" concept, in which attractive poly(ethyl acrylate-random-methyl acrylate) chains are dynamically crosslinked via repulsively segregated fluoroalkyl side chains attached along the main chain. The resulting elastomer self-heals rapidly (> 90% within 15 min) via weak but abundant van der Waals interactions among matrix polymers, while the dynamic crosslinking provides high fracture stress (≈2 MPa) and good toughness (≈17 MJ m<sup>-3</sup>). The elastomer has a nonsticky surface and selectively self-heals only at the damaged faces due to the surface segregation of the fluoroalkyl chains. Moreover, our elastomer strongly adheres to polytetrafluoroethylene plates (≈60 N cm<sup>-2</sup>) via hot pressing. Elastomer ; Materials science ; Polymer ; Toughness ; Self-healing ; Acrylate ; van der Waals force ; Composite material ; Side chain ; Self-healing material ; Copolymer ; Molecule ; Chemistry Polymer composites and self-healing ; Advanced Sensor and Energy Harvesting Materials ; Synthetic Organic Chemistry Methods
Authors: Tore Brinck | André Nyberg Borrfors
Source: Journal of Molecular Modeling (article, 2022-08-25)
Field: Chemistry — Physical and Theoretical Chemistry

The Importance of Electrostatics and Polarization for Noncovalent Interactions: Ionic Hydrogen Bonds vs Ionic Halogen Bonds A series of 26 hydrogen-bonded complexes between Br<sup>-</sup> and halogen, oxygen and sulfur hydrogen-bond (HB) donors is investigated at the M06-2X/6-311 + G(2df,2p) level of theory. Analysis using a model in which Br<sup>-</sup> is replaced by a point charge shows that the interaction energy ([Formula: see text]) of the complexes is accurately reproduced by the scaled interaction energy with the point charge ([Formula: see text]).This is demonstrated by [Formula: see text] with a correlation coefficient, R<sup>2</sup> =0.999. The only outlier is (Br-H-Br)<sup>-</sup>, which generally is classified as a strong charge-transfer complex with covalent character rather than a HB complex. [Formula: see text] can be divided rigorously into an electrostatic contribution ([Formula: see text]) and a polarization contribution ([Formula: see text]).Within the set of HB complexes investigated, the former varies between -7.2 and -32.7 kcal mol<sup>-1</sup>, whereas the latter varies between -1.6 and -11.5 kcal mol<sup>-1</sup>. Compared to our previous study of halogen-bonded (XB) complexes between Br<sup>-</sup> and C-Br XB donors, the electrostatic contribution is generally stronger and the polarization contribution is generally weaker in the HB complexes. However, for both types of bonding, the variation in interaction strength can be reproduced accurately without invoking a charge-transfer term. For the Br<sup>-</sup>···HF complex, the importance of charge penetration on the variation of the interaction energy with intermolecular distance is investigated. It is shown that the repulsive character of [Formula: see text] at short distances in this complex to a large extent can be attributed to charge penetration. Chemistry ; Ionic bonding ; Hydrogen bond ; Halogen ; Interaction energy ; Halogen bond ; Crystallography ; Intermolecular force ; Electrostatics ; Non-covalent interactions ; Computational chemistry ; Atomic physics ; Physical chemistry ; Molecule ; Physics ; Ion ; Organic chemistry Crystallography and molecular interactions ; Solid-state spectroscopy and crystallography ; Inorganic Fluorides and Related Compounds
Authors: Jorge M. Núñez | Simón Hettler | Enio Lima | Gerardo F. Goya | Raúl Arenal | Roberto D. Zysler | Myriam H. Aguirre | E. Winkler
Source: Journal of Materials Chemistry C (article, 2022-01-01)
Field: Materials Science — Materials Chemistry

Onion-like Fe<sub>3</sub>O<sub>4</sub>/MgO/CoFe<sub>2</sub>O<sub>4</sub> magnetic nanoparticles: new ways to control magnetic coupling between soft and hard magnetic phases Nanoparticles with onion-like architecture offer a unique opportunity to modulate the coupling between magnetic phases by introducing spacers into the same structure. Here we report the case of Fe 3 O 4 /MgO/CoFe 2 O 4 core/shell/shell nanoparticles system. Ferrimagnetism ; Materials science ; Coercivity ; Magnetization ; Exchange bias ; Nanoparticle ; Magnetic nanoparticles ; Condensed matter physics ; Magnetic hysteresis ; Nanotechnology ; Nuclear magnetic resonance ; Analytical Chemistry (journal) ; Magnetic anisotropy ; Magnetic field ; Chemistry Magnetic Properties and Synthesis of Ferrites ; Magnetic properties of thin films ; Multiferroics and related materials
Authors: Ze-Dong Yu | Jing-Yi Cao | Hualong Li | Guang Yang | Zeng-Min Xue | Lu Jiang | Jiaying Yu | Chuan‐Zeng Wang | Xiangyu Liu | Carl Redshaw | Takehiko Yamato
Source: New Journal of Chemistry (article, 2022-01-01)
Field: Materials Science — Materials Chemistry

Structure-controlled intramolecular charge transfer in asymmetric pyrene-based luminogens: synthesis, characterization and optical properties Four asymmetric D–A type pyrene-based luminogens with tunable optical properties were synthesized, which provide an efficient strategy to achieve pyrene-based full-color photoelectric materials. Chemistry ; Pyrene ; Intramolecular force ; Characterization (materials science) ; Charge (physics) ; Photochemistry ; Combinatorial chemistry ; Organic chemistry ; Nanotechnology Luminescence and Fluorescent Materials ; Porphyrin and Phthalocyanine Chemistry ; Molecular Sensors and Ion Detection
Authors: Sejung Kim | Stephen Palani | Fehmi Çivitçi | Xiaolin Nan | Stuart Ibsen
Source: Small (article, 2022-10-21)
Field: Materials Science — Electronic, Optical and Magnetic Materials

A Versatile Synthetic Pathway for Producing Mesostructured Plasmonic Nanostructures Highly branched gold (Au) nanostructures with sharp tips are considered excellent substrates for surface-enhanced Raman scattering (SERS)-based sensing technologies. Here, a simple synthetic route for producing Au or Au-Ag bimetallic mesostructures with multiple sharpened tips in the presence of carbon quantum dots (CQDs) is presented. The morphologies of these mesostructured plasmonic nanoparticles (MSPNs) can be controlled by adjusting the concentration of CQDs, reaction temperatures, and seed particles. The optimal molar ratio for [HAuCl<sub>4</sub> ]/[CQDs] is found to be ≈25. At this molar ratio, the diameters of MSPNs can be tuned from 80 to 200 nm by changing the reaction temperature from 25 to 80 °C. In addition, it is found that hierarchical MSPNs consisting of multiple Au nanocrystals can be formed over the entire seed particle surface. Finally, the SERS activity of these MSPNs is examined through the detection of rhodamine 6G and methylene blue. Of the different mesostructures, the bimetallic MSPNs have the highest sensitivity with the ability to detect 10<sup>-7</sup> m of rhodamine 6G and 10<sup>-6</sup> m of methylene blue. The properties of these MSPN particles, made using a novel synthetic process, make them excellent candidates for SERS-based chemical sensing applications. Rhodamine 6G ; Bimetallic strip ; Materials science ; Nanoparticle ; Plasmon ; Raman spectroscopy ; Nanotechnology ; Nanostructure ; Methylene blue ; Raman scattering ; Chemical engineering ; Rhodamine B ; Particle (ecology) ; Nanorod ; Molecule ; Photocatalysis ; Catalysis ; Optoelectronics ; Organic chemistry ; Chemistry ; Metal Gold and Silver Nanoparticles Synthesis and Applications ; Carbon and Quantum Dots Applications ; Advanced Nanomaterials in Catalysis
Authors: Vrushali Kharate | Mohini Kuchekar | Minal T. Harde | Bhushan Pimple | Vinita Patole | Manisha Salunkhe | Pooja Wadgave | Manish R. Bhise | Asmita Gaikwad | Harshal Tare
Source: International Journal of Drug Delivery Technology (article, 2022-06-25)
Field: Chemistry — Analytical Chemistry

Development of Validated Stability Indicating HPTLC Method for Estimation of Febuxostat in Bulk and Tablet Dosage Form by Using QBD Approach Objective: Development of a simple, reliable, time-tested, stability-focused HPTLC method for determining febuxostat (FEB) in bulk and pharmaceutical formulation.Methods: Chloroform, methanol, and formic acid (6.7:2.9:0.1v/v/v) served as the mobile phase, and precoated aluminum TLC plates served as the stationary phase. Active drug FEB was subjected to a densitometric measurement (absorbance mode at 312 nm). The present study performed a comprehensive stress test of FEBas per ICH Q1A(R2) guidelines. FEB has undergone forced degradation by acid, alkali (0.5N HCl and NaOH), oxidative (3% H2O2), H2O and photolytic effect. Results: Calibration plots using HPTLC linear regression analysis indicated a strong correlation (r2 = 0.999) between concentrations from 150 to 900 ng/spot. Accuracy, recoverability, robustness, and documentation are some of the aspects of the method that have been verified. The LoD was 189 ng and the LoQ was 395 ng per location. FEB was not degraded under acid, UV, water, peroxide and photolytic conditions but showed degradation under alkaline conditions. Conclusion: Stability studies and quantification of FEB in bulk and pharmaceutical dose forms by QBD methodology have both been shown to benefit from the suggested HPTLC method. This technique can be utilized as a stability indicator because it successfully isolates the medication from the degradation product. Chromatography ; Chemistry ; Forced degradation ; Absorbance ; Dosage form ; Febuxostat ; Pharmaceutical formulation ; Methanol ; Formic acid ; Calibration curve ; Detection limit ; Organic chemistry Analytical Methods in Pharmaceuticals ; Analytical Chemistry and Chromatography ; Multicomponent Synthesis of Heterocycles
Authors: Karl G. Schuchard | Advay Pawar | B. E. Anderson | Behnam Pourdeyhimi | Rohan A. Shirwaiker
Source: Industrial & Engineering Chemistry Research (article, 2022-09-06)
Field: Materials Science — Polymers and Plastics

Multiphase CFD Modeling and Experimental Validation of Polymer and Attenuating Air Jet Interactions in Nonwoven Annular Melt Blowing In annular melt blowing, fiber formation is achieved by accelerating a molten polymer via drag forces imparted by high velocity air that attenuates the polymer jet diameter. The interactions at the polymer-air interface, which govern the motion of the jets and impact the resulting fiber characteristics, are important but not well understood yet. This work details the development and validation of a multiphase computational fluid dynamics (CFD) model to investigate these interactions and the effects of three key melt blowing process parameters (polymer viscosity and throughput, and air velocity) on two critical fiber attributes - whipping instability and fiber diameter. Simulation results highlighted that whipping instability was driven by the polymer-air velocity differential, and the fiber diameter was primarily modulated by polymer throughput and air velocity. The CFD model was validated by modulating the polymer and air throughputs and analyzing the fiber diameter experimentally. Empirical results showed good agreement between fabricated and model-estimated fiber diameters, especially at lower air velocities. An additional CFD simulation performed using a melt blowing nozzle geometry and process parameters described in literature also confirmed good correlation between model estimates and literature empirical data. Jet (fluid) ; Computational fluid dynamics ; Materials science ; Mechanics ; Polymer ; Physics ; Composite material Textile materials and evaluations ; Aerosol Filtration and Electrostatic Precipitation ; Electrospun Nanofibers in Biomedical Applications