jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Sandeep Hatte | R. Pitchumani
Source: Langmuir (article, 2020-11-16)
Field: Materials Science — Surfaces, Coatings and Films

Fractal Model for Drag Reduction on Multiscale Nonwetting Rough Surfaces Rough surfaces in contact with a flow of fluid exhibit alternating no-slip and free shear boundary conditions at the solid-liquid and air-liquid interfaces, respectively, thereby potentially offering drag reduction benefits. The balance between the dynamic pressure in the flow and the restoring capillary pressure in the interasperity spaces determines the stability of the Cassie state of wettability and is a function of the relative extent of no-slip and free shear regions per unit surface area. In the present study, using a fractal representation of rough surface topography, an analytical model is developed to quantify the stability of the Cassie state of wettability as well as drag reduction and the friction factor for laminar flow in a rectangular channel between nonwetting multiscale rough surfaces. A systematic study is conducted to quantify the effects of fractal parameters of the surfaces and the flow Reynolds number on drag reduction and the friction factor. The studies are used to develop friction factor curves extending the classical Moody diagram to hydrophobic and superhydrophobic surfaces. On the basis of the studies, regime maps are derived for estimating the extent of drag reduction offered by hydrophobic and superhydrophobic surfaces, revealing that superhydrophobic surfaces do not always offer the best drag reduction performance. The application of the fractal model to practical topographies of nonwetting surfaces of copper, aluminum, and zinc oxide fabricated via electrodeposition and etching is also discussed. Drag ; Laminar flow ; Wetting ; Mechanics ; Slip (aerodynamics) ; Fractal dimension ; Reynolds number ; Fractal ; Materials science ; Chemistry ; Composite material ; Turbulence ; Thermodynamics ; Physics ; Mathematics Surface Modification and Superhydrophobicity ; Adhesion, Friction, and Surface Interactions ; Fluid Dynamics and Thin Films
Authors: Ernesto Rufino‐Felipe | Hugo Valdés | Juan Manuel Germán-Acacio | Viviana Reyes‐Márquez | David Morales‐Morales
Source: Journal of Organometallic Chemistry (article, 2020-06-11)
Field: Chemistry — Organic Chemistry

Fluorinated N-Heterocyclic carbene complexes. Applications in catalysis Chemistry ; Carbene ; Steric effects ; Catalysis ; Transition metal ; Combinatorial chemistry ; Organometallic chemistry ; Fluorine ; Nanotechnology ; Organic chemistry N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Catalytic Cross-Coupling Reactions ; Carbon dioxide utilization in catalysis
Authors: Madhusudan K. Pandey | Joyanta Choudhury
Source: ACS Omega (review, 2020-11-23)
Field: Chemistry — Inorganic Chemistry

Ester Hydrogenation with Bifunctional Metal–NHC Catalysts: Recent Advances Hydrogenation of ester to alcohol is an essential reaction in organic chemistry due to its importance in the production of a wide range of bulk and fine chemicals. There are a number of homogeneous and heterogeneous catalyst systems reported in the literature for this useful reaction. Mostly, phosphine-based bifunctional catalysts, owing to their ability to show metal-ligand cooperation during catalytic reactions, are extensively used in these reactions. However, phosphine-based catalysts are difficult to synthesize and are also highly air- and moisture-sensitive, restricting broad applications. In contrast, N-heterocyclic carbenes (NHCs) can be easily synthesized, and their steric and electronic attributes can be fine-tuned easily. In recent times, many phosphine ligands have been replaced by potent σ-donor NHCs, and the resulting bifunctional metal-ligand systems are proven to be very efficient in several important catalytic reactions. This mini-review focuses the recent advances mainly on bifunctional metal-NHC complexes utilized as (pre)catalysts in ester hydrogenation reactions. Bifunctional ; Phosphine ; Catalysis ; Ligand (biochemistry) ; Chemistry ; Combinatorial chemistry ; Homogeneous catalysis ; Steric effects ; Organic chemistry ; Metal Asymmetric Hydrogenation and Catalysis ; N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Catalytic Cross-Coupling Reactions
Authors: Hang Thi Thuy Vu | Viet Le Nam Vo | Young‐Min Chung
Source: Applied Catalysis A General (article, 2020-09-28)
Field: Materials Science — Materials Chemistry

Geometric, electronic, and synergistic effect in the sulfonated carbon-supported Pd catalysts for the direct synthesis of hydrogen peroxide Chemistry ; Catalysis ; Selectivity ; Hydrogen peroxide ; Palladium ; Carbon fibers ; Inorganic chemistry ; Organic chemistry ; Composite number ; Materials science Catalytic Processes in Materials Science ; Nanomaterials for catalytic reactions ; Advanced Photocatalysis Techniques
Authors: Alexander P. Voronin | Artem O. Surov | Andrei V. Churakov | Olga D. Parashchuk | Alexey A. Rykounov | Mikhail V. Vener
Source: Molecules (article, 2020-05-21)
Field: Chemistry — Physical and Theoretical Chemistry

Combined X-ray Crystallographic, IR/Raman Spectroscopic, and Periodic DFT Investigations of New Multicomponent Crystalline Forms of Anthelmintic Drugs: A Case Study of Carbendazim Maleate Synthesis of multicomponent solid forms is an important method of modifying and fine-tuning the most critical physicochemical properties of drug compounds. The design of new multicomponent pharmaceutical materials requires reliable information about the supramolecular arrangement of molecules and detailed description of the intermolecular interactions in the crystal structure. It implies the use of a combination of different experimental and theoretical investigation methods. Organic salts present new challenges for those who develop theoretical approaches describing the structure, spectral properties, and lattice energy <i>E</i><sub>latt</sub>. These crystals consist of closed-shell organic ions interacting through relatively strong hydrogen bonds, which leads to <i>E</i><sub>latt</sub> > 200 kJ/mol. Some technical problems that a user of periodic (solid-state) density functional theory (DFT) programs encounters when calculating the properties of these crystals still remain unsolved, for example, the influence of cell parameter optimization on the <i>E</i><sub>latt</sub> value, wave numbers, relative intensity of Raman-active vibrations in the low-frequency region, etc. In this work, various properties of a new two-component carbendazim maleate crystal were experimentally investigated, and the applicability of different DFT functionals and empirical Grimme corrections to the description of the obtained structural and spectroscopic properties was tested. Based on this, practical recommendations were developed for further theoretical studies of multicomponent organic pharmaceutical crystals. Intermolecular force ; Lattice energy ; Raman spectroscopy ; Density functional theory ; Crystal structure ; Supramolecular chemistry ; Hydrogen bond ; Molecule ; Materials science ; Lattice (music) ; Crystal structure prediction ; Computational chemistry ; Chemical physics ; Crystallography ; Chemistry ; Organic chemistry ; Physics ; Optics Crystallography and molecular interactions ; Crystallization and Solubility Studies ; Chemical Thermodynamics and Molecular Structure
Authors: Shengyu Shi | Chenzhi Yao | Jie Cen | Lei Li | Guhuan Liu | Jinming Hu | Shiyong Liu
Source: Angewandte Chemie International Edition (article, 2020-07-09)
Field: Chemistry — Organic Chemistry

High‐Fidelity End‐Functionalization of Poly(ethylene glycol) Using Stable and Potent Carbamate Linkages Commercial PEG-amine is of unreliable quality, and conventional PEG functionalization relies on esterification and etherification steps, suffering from incomplete conversion, harsh reaction conditions, and functional-group incompatibility. To solve these challenges, we propose an efficient strategy for PEG functionalization with carbamate linkages. By fine-tuning terminal amine basicity, stable and high-fidelity PEG-amine with carbamate linkage was obtained, as seen from the clean MALDI-TOF MS pattern. The carbamate strategy was further applied to the synthesis of high-fidelity multi-functionalized PEG with varying reactive groups. Compared to with an ester linkage, amphiphilic PEG-PS block copolymers bearing carbamate junction linkage exhibits preferential self-assembly tendency into vesicles. Moreover, nanoparticles of the latter demonstrate higher drug loading efficiency, encapsulation stability against enzymatic hydrolysis, and improved in vivo retention at the tumor region. Carbamate ; Surface modification ; Ethylene glycol ; Combinatorial chemistry ; Amine gas treating ; PEG ratio ; Chemistry ; Copolymer ; Amphiphile ; Hydrolysis ; Polymer chemistry ; Organic chemistry ; Polymer Advanced Polymer Synthesis and Characterization ; Nanoparticle-Based Drug Delivery ; Polymer Surface Interaction Studies
Authors: Srinivasulu Aitipamula | Surajit Das
Source: European Journal of Pharmaceutics and Biopharmaceutics (article, 2020-02-05)
Field: Chemistry — Physical and Theoretical Chemistry

Cocrystal formulations: A case study of topical formulations consisting of ferulic acid cocrystals Cocrystal ; Chemistry ; Solubility ; Active ingredient ; Isonicotinamide ; Anhydrous ; Ferulic acid ; Organic chemistry ; Tableting ; Chromatography ; Nicotinamide ; Hydrogen bond ; Molecule Crystallography and molecular interactions ; Crystallization and Solubility Studies ; Chemical Thermodynamics and Molecular Structure
Authors: Anna Rovira | Miriam Pujals | Albert Gandioso | Marta López‐Corrales | Manel Bosch | Vicente Marchán
Source: The Journal of Organic Chemistry (article, 2020-04-02)
Field: Chemistry — Spectroscopy

Modulating Photostability and Mitochondria Selectivity in Far-Red/NIR Emitting Coumarin Fluorophores through Replacement of Pyridinium by Pyrimidinium Mitochondrial dysfunction has been associated with several human pathological conditions, including cancer, aging, and neurodegenerative diseases. Thus, the availability of selective fluorescent probes for mitochondria could play an important role in the future for monitoring cellular functions and disease progression. In this work, we have studied how the photophysical properties and subcellular accumulation of nonconventional coumarin-based COUPY fluorophores can be fine-tuned through replacement of the <i>para</i>-pyridinium moiety with several heterocycles. Among them, <i>ortho,para</i>-pyrimidinium substitution provided novel fluorophores with suitable photophysical properties for bioimaging applications, including emission in the far-red to NIR region, large Stokes' shifts, and high photostability. Furthermore, the compounds exhibited excellent cell membrane permeability in living cells and a higher selectivity for mitochondria compared with the parent COUPY fluorophores. Overall, these results provided useful insights into the development of novel mitochondria-targeted fluorescent probes based on small organic molecules, since higher selectivity for this organelle can be achieved through the replacement of conventional N-alkylated pyridinium moieties by the corresponding N-alkylated-<i>ortho,para</i>-pyrimidinium counterparts. Pyridinium ; Chemistry ; Coumarin ; Fluorescence ; Selectivity ; Moiety ; Mitochondrion ; Biophysics ; Small molecule ; Membrane ; Combinatorial chemistry ; Biochemistry ; Stereochemistry ; Organic chemistry Molecular Sensors and Ion Detection ; Luminescence and Fluorescent Materials ; Nanoplatforms for cancer theranostics
Authors: Katie L. Cavanagh | Gislaine Kuminek | Naír Rodríguez‐Hornedo
Source: Molecular Pharmaceutics (article, 2020-08-20)
Field: Materials Science — Materials Chemistry

Cocrystal Solubility Advantage and Dose/Solubility Ratio Diagrams: A Mechanistic Approach To Selecting Additives and Controlling Dissolution–Supersaturation–Precipitation Behavior Two of the main questions regarding cocrystal selection and formulation development are whether the will be stable and how fast can it dissolve the drug dose. Dissolving the drug dose may require cocrystals with a high solubility advantage over drug (SA = <i>S</i><sub>CC</sub>/<i>S</i><sub>D</sub>), but these may have limited potential to sustain drug supersaturation. Thus, we propose a twofold approach to mitigate the risk of drug precipitation by optimizing thermodynamic (SA) and kinetic factors (nucleation inhibitors). This risk can be evaluated by considering the cocrystal SA and drug dose/solubility ratio (<i>D</i><sub>0D</sub> = <i>C</i><sub>dose</sub>/<i>S</i><sub>D</sub>), which in tandem represent the maximum theoretical supersaturation that a cocrystal may generate, the driving force for drug precipitation, and the potential for dose-/solubility-limited absorption. cocrystals with SA and <i>D</i><sub>0D</sub> values above critical supersaturation are prone to rapid precipitation, often negating their utility as a solubility enhancement tool. This work presents a mechanistic approach to controlling the dissolution-supersaturation-precipitation behavior of cocrystal systems, whereby relationships between SA, <i>D</i><sub>0D</sub>, and the drug-solubilizing power of surfactants (SP<sub>D</sub> = <i>S</i><sub>D,T</sub>/<i>S</i><sub>D,aq</sub>) are used to fine-tune cocrystal-inherent supersaturation by rational additive selection. Experimental results with danazol-vanillin cocrystal demonstrate how SA, <i>D</i><sub>0D</sub>, and SP<sub>D</sub> are key thermodynamic parameters to understanding the kinetic cocrystal behavior and how the risks of cocrystal development may be mitigated through the mechanistic formulation design. Cocrystal ; Supersaturation ; Solubility ; Dissolution ; Precipitation ; Chemistry ; Nucleation ; Chemical engineering ; Thermodynamics ; Organic chemistry ; Molecule Crystallization and Solubility Studies ; Crystallography and molecular interactions ; Phenothiazines and Benzothiazines Synthesis and Activities
Authors: Thabang Calvin Lebepe | Sundararajan Parani | Oluwatobi S. Oluwafemi
Source: Nanomaterials (review, 2020-10-28)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Graphene Oxide-Coated Gold Nanorods: Synthesis and Applications The application of gold nanorods (AuNRs) and graphene oxide (GO) has been widely studied due to their unique properties. Although each material has its own challenges, their combination produces an exceptional material for many applications such as sensor, therapeutics, and many others. This review covers the progress made so far in the synthesis and application of GO-coated AuNRs (GO-AuNRs). Initially, it highlights different methods of synthesizing AuNRs and GO followed by two approaches (ex situ and in situ approaches) of coating AuNRs with GO. In addition, the properties of GO-AuNRs composite such as biocompatibility, photothermal profiling, and their various applications, which include photothermal therapy, theranostic, sensor, and other applications of GO-AuNRs are also discussed. The review concludes with challenges associated with GO-AuNRs and future perspectives. Nanorod ; Photothermal therapy ; Nanotechnology ; Graphene ; Materials science ; Biocompatibility ; Oxide ; Coating ; Metallurgy Gold and Silver Nanoparticles Synthesis and Applications ; Graphene and Nanomaterials Applications ; Advanced Nanomaterials in Catalysis
Authors: Yiqi Fan | Jinjin Zhang | Zhouyi Hong | Huayu Qiu | Yang Li | Shouchun Yin
Source: Polymers (review, 2020-12-27)
Field: Materials Science — Materials Chemistry

Architectures and Applications of BODIPY-Based Conjugated Polymers Conjugated polymers generally contain conjugated backbone structures with benzene, heterocycle, double bond, or triple bond, so that they have properties similar to semiconductors and even conductors. Their energy band gap is very small and can be adjusted via chemical doping, allowing for excellent photoelectric properties. To obtain prominent conjugated materials, numerous well-designed polymer backbones have been reported, such as polyphenylenevinylene, polyphenylene acetylene, polycarbazole, and polyfluorene. 4,4'-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-based conjugated polymers have also been prepared owing to its conjugated structure and intriguing optical properties, including high absorption coefficients, excellent thermal/photochemical stability, and high quantum yield. Most importantly, the properties of BODIPYs can be easily tuned by chemical modification on the dipyrromethene core, which endows the conjugated polymers with multiple functionalities. In this paper, BODIPY-based conjugated polymers are reviewed, focusing on their structures and applications. The forms of BODIPY-based conjugated polymers include linear, coiled, and porous structures, and their structure-property relationship is explored. Also, typical applications in optoelectronic materials, sensors, gas/energy storage, biotherapy, and bioimaging are presented and discussed in detail. Finally, the review provides an insight into the challenges in the development of BODIPY-based conjugated polymers. Conjugated system ; Materials science ; Polymer ; BODIPY ; Polyfluorene ; Band gap ; Quantum yield ; Photochemistry ; Thermal stability ; Nanotechnology ; Polymer chemistry ; Organic chemistry ; Optoelectronics ; Fluorescence ; Chemistry ; Composite material ; Optics Luminescence and Fluorescent Materials ; Covalent Organic Framework Applications ; Porphyrin and Phthalocyanine Chemistry
Authors: Lucia Massi | Adrian Najer | Robert Chapman | Christopher D. Spicer | Valeria Nele | Junyi Che | Marsilea A. Booth | James Doutch | Molly M. Stevens
Source: Journal of Materials Chemistry B (article, 2020-01-01)
Field: Materials Science — Biomaterials

Tuneable peptide cross-linked nanogels for enzyme-triggered protein delivery Many diseases are associated with the dysregulated activity of enzymes, such as matrix metalloproteinases (MMPs). This dysregulation can be leveraged in drug delivery to achieve disease- or site-specific cargo release. Self-assembled polymeric nanoparticles are versatile drug carrier materials due to the accessible diversity of polymer chemistry. However, efficient loading of sensitive cargo, such as proteins, and introducing functional enzyme-responsive behaviour remain challenging. Herein, peptide-crosslinked, temperature-sensitive nanogels for protein delivery were designed to respond to MMP-7, which is overexpressed in many pathologies including cancer and inflammatory diseases. The incorporation of N-cyclopropylacrylamide (NCPAM) into N-isopropylacrylamide (NIPAM)-based copolymers enabled us to tune the polymer lower critical solution temperature from 33 to 44 °C, allowing the encapsulation of protein cargo and nanogel-crosslinking at slightly elevated temperatures. This approach resulted in nanogels that were held together by MMP-sensitive peptides for enzyme-specific protein delivery. We employed a combination of cryogenic transmission electron microscopy (cryo-TEM), dynamic light scattering (DLS), small angle neutron scattering (SANS), and fluorescence correlation spectroscopy (FCS) to precisely decipher the morphology, self-assembly mechanism, enzyme-responsiveness, and model protein loading/release properties of our nanogel platform. Simple variation of the peptide linker sequence and combining multiple different crosslinkers will enable us to adjust our platform to target specific diseases in the future. Peptide ; Materials science ; Enzyme ; Nanotechnology ; Biochemistry ; Chemistry Nanoparticle-Based Drug Delivery ; Supramolecular Self-Assembly in Materials ; RNA Interference and Gene Delivery
Authors: Frédéric Brunel | Christelle Lautard | Frédéric Garzino | Jean‐Manuel Raimundo | Jean‐Michel Bolla | Michel Camplo
Source: Bioorganic & Medicinal Chemistry Letters (article, 2020-07-10)
Field: Chemistry — Organic Chemistry

Phosphonium-ammonium-based di-cationic ionic liquids as antibacterial over the ESKAPE group Chemistry ; Phosphonium ; Cationic polymerization ; Antibacterial activity ; Phosphonium salt ; Ammonium ; Alkyl ; Antimicrobial ; Ionic bonding ; Salt (chemistry) ; Bacteria ; Combinatorial chemistry ; Ion ; Organic chemistry Antimicrobial agents and applications ; Ionic liquids properties and applications ; Multicomponent Synthesis of Heterocycles
Authors: L. Pino | Cristina Italiano | M. Laganà | Antonio Vita | V. Recupero
Source: Catalysis Science & Technology (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Kinetic study of the methane dry (CO<sub>2</sub>) reforming reaction over the Ce<sub>0.70</sub>La<sub>0.20</sub>Ni<sub>0.10</sub>O<sub>2−δ</sub>catalyst The kinetic behaviour of the Ce<sub>0.70</sub>La<sub>0.20</sub>Ni<sub>0.10</sub>O<sub>2−δ</sub>catalyst during the methane dry reforming reaction was investigated in a fixed bed reactor in the temperature range of 923–1023 K with the partial pressure of CH<sub>4</sub>and CO<sub>2</sub>ranging between 5 and 50 kPa. Methane ; Carbon dioxide reforming ; Catalysis ; Kinetic energy ; Chemistry ; Physical chemistry ; Materials science ; Syngas ; Inorganic chemistry ; Physics ; Organic chemistry Catalytic Processes in Materials Science ; Catalysts for Methane Reforming ; Catalysis and Oxidation Reactions
Authors: Aleksandar Matković | Andreas Petritz | Gerburg Schider | Markus Krammer | Markus Kratzer | Esther Karner‐Petritz | Alexander Fian | Herbert Gold | Michael Gärtner | Andreas Terfort | Christian Teichert | Egbert Zojer | Karin Zojer | Barbara Stadlober
Source: Advanced Electronic Materials (article, 2020-03-18)
Field: Materials Science — Materials Chemistry

Interfacial Band Engineering of MoS<sub>2</sub>/Gold Interfaces Using Pyrimidine‐Containing Self‐Assembled Monolayers: Toward Contact‐Resistance‐Free Bottom‐Contacts Abstract Bottom‐contact architectures with common electrode materials such as gold are crucial for the integration of 2D semiconductors into existing device concepts. The high contact resistance to gold—especially for bottom contacts—is, however, a general problem in 2D semiconductor thin‐film transistors. Pyrimidine‐containing self‐assembled monolayers on gold electrodes are investigated for tuning the electrode work functions in order to minimize that contact resistance. Their frequently ignored asymmetric and bias‐dependent nature is recorded by Kelvin probe force microscopy through a direct mapping of the potential drop across the channel during device operation. A reduction of the contact resistances exceeding two orders of magnitude is achieved via a suitable self‐assembled monolayer, which vastly improves the overall device performance. Monolayer ; Contact resistance ; Materials science ; Electrode ; Semiconductor ; Nanotechnology ; Self-assembled monolayer ; Optoelectronics ; Transistor ; Kelvin probe force microscope ; Atomic force microscopy ; Layer (electronics) ; Voltage ; Electrical engineering ; Chemistry 2D Materials and Applications ; Advanced Sensor and Energy Harvesting Materials ; Ferroelectric and Negative Capacitance Devices