jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Md. Saddam Sheikh | Md. Juel Sarder | A.H. Bhuiyan | Mohammad Jellur Rahman
Source: Heliyon (article, 2023-07-20)
Field: Materials Science — Polymers and Plastics

Structural and optical behaviours of methyl acrylate-vinyl acetate composite thin films synthesized under dynamic low-pressure plasma Low-pressure (33.33 Pa) plasma polymerized methyl acrylate and vinyl acetate composite thin films with various monomer compositions were deposited onto glass substrates. Under the same plasma conditions, the homopolymer thin films were also prepared. The thickness of the composite films was observed to vary between 117 and 213 nm depending on the monomer ratio. The composite films exhibit a smooth, pinhole-free, and immaculate surface morphology, surpassing that of the homopolymers. The energy dispersive x-ray study shows that the films contain mainly carbon and oxygen with 26.09-37.20 at% and 35.03 - 40.10 at%, respectively. The composite films contain more carbon contents which enhance the film stability. The appearance of some broad absorption bands in the Fourier transform infrared spectroscopy indicates structural changes in the PP films caused by the restructuring or dilapidation of monomer molecules while forming the polymer. The UV-visible spectra analysis reveal that the composite films exhibited a tunable optical band gap by adjusting the monomer ratio. The decrease of methyl acrylate monomer reduces the direct and indirect optical band-gap values of composite films from 3.15 to 3.00 eV and 2.35 to 1.74 eV, respectively. While Urbach energy values increases from 0.33 eV to 0.90 eV. All the films showed good transmittance properties (86 - 96%) in the visible range wavelength (550 - 800 nm). Other optical parameters are also found better in composite films which indicates the aptness of the composite films in various optoelectronic or electronic applications. Composite number ; Vinyl acetate ; Methyl acrylate ; Plasma ; Acrylate ; Materials science ; Thin film ; Chemical engineering ; Polymer chemistry ; Composite material ; Nanotechnology ; Polymer ; Copolymer ; Engineering ; Physics Polymer Nanocomposite Synthesis and Irradiation ; Synthesis and properties of polymers ; Photopolymerization techniques and applications
Authors: Léo Boivin | Adrien Schlachter | Daniel Fortin | Pierre D. Harvey
Source: Inorganic Chemistry (article, 2023-12-18)
Field: Chemistry — Inorganic Chemistry

Truxene-to-Fluorenone Energy Transfer in a Robust Mesoporous Zn-MOF A new metal-organic framework (MOF; [Zn<sub>4</sub>O(<b>hett</b>)<sub>4/3</sub>(<b>fluo</b>)<sub>1/2</sub>(<b>bdc</b>)<sub>1/2</sub>]<i><sub>n</sub></i>; <b>TFT-MOF</b>) constructed on chromophoric ligands 5,5',10,10',15,15'-hexaethyltruxene-2,7,12-triacetate (<b>hett</b>), 9-fluorenone-2,7-dicarboxylate (<b>fluo</b>), terephthalate (<b>bdc</b>), and the Zn<sub>4</sub>O node has been prepared and identified by powder X-ray diffraction. This luminescent MOF exhibits large mesoporous pores of 2.7 nm based on computer modeling using density functional theory (DFT) calculations. The steady-state and time-resolved fluorescence spectra and photophysical parameters of <b>TFT-MOF</b> have been investigated and compared with those of the free ligands and their basic chromophores. All in all, <b>TFT-MOF</b> exhibits particularly efficient singlet-singlet energy-transfer processes described as <sup>1</sup>(<b>hett</b>)* → (<b>fluo</b>) and <sup>1</sup>(<b>bdc</b>)* → (<b>fluo</b>), leading to fluorescence arising for the <b>fluo</b> lumophore operating only through Förster resonance energy transfer (FRET) with an efficiency of transfer of up to >95%. This experimental conclusion was corroborated by DFT and time-dependent DFT (TDDFT). For the <sup>1</sup>(<b>hett</b>)* → (<b>fluo</b>) process, the approximated overall rate constant of energy transfer was evaluated to be at most 2.04 × 10<sup>10</sup> s<sup>-1</sup> (using a Stern-Volmer approach of solution data and the relationship between distance and concentration). This process was analyzed using the Förster theory, where two intrapore energy transfer paths of center-to-center distances of 13 and 25 Å have been identified. <b>TFT-MOF</b> photosensitizes the formation of singlet oxygen (<sup>1</sup>O<sub>2</sub> (<sup>1</sup>Σ<sub>g</sub>)) as detected by its phosphorescence signal at 1275 nm. Chemistry ; Phosphorescence ; Förster resonance energy transfer ; Singlet oxygen ; Time-dependent density functional theory ; Singlet state ; Density functional theory ; Metal-organic framework ; Chromophore ; Fluorenone ; Photochemistry ; Fluorescence ; Physical chemistry ; Computational chemistry ; Excited state ; Organic chemistry ; Atomic physics ; Fluorene ; Polymer ; Oxygen Metal-Organic Frameworks: Synthesis and Applications ; Magnetism in coordination complexes ; Perovskite Materials and Applications
Authors: Jonathan Bietsch | Logan Baker | Anna Duffney | Alice Mao | Mary A. Foutz | Cheandri Ackermann | Guijun Wang
Source: Gels (article, 2023-05-27)
Field: Materials Science — Biomaterials

Para-Methoxybenzylidene Acetal-Protected D-Glucosamine Derivatives as pH-Responsive Gelators and Their Applications for Drug Delivery Carbohydrate-based low molecular weight gelators (LMWGs) are compounds with the capability to self-assemble into complex molecular networks within a solvent, leading to solvent immobilization. This process of gel formation depends on noncovalent interactions, including Van der Waals, hydrogen bonding, and π-π stacking. Due to their potential applications in environmental remediation, drug delivery, and tissue engineering, these molecules have emerged as an important area of research. In particular, various 4,6-<i>O</i>-benzylidene acetal-protected D-glucosamine derivatives have shown promising gelation abilities. In this study, a series of C-2-carbamate derivatives containing a para-methoxy benzylidene acetal functional group were synthesized and characterized. These compounds exhibited good gelation properties in several organic solvents and aqueous mixtures. Upon removal of the acetal functional group under acidic conditions, a number of deprotected free sugar derivatives were also synthesized. Analysis of these free sugar derivatives revealed two compounds were hydrogelators while their precursors did not form hydrogels. For those protected carbamates that are hydrogelators, removal of the 4,6-protection will result in a more water-soluble compound that produces a transition from gel to solution. Given the ability of these compounds to form gels from solution or solution from gels in situ in response to acidic environments, these compounds may have practical applications as stimuli-responsive gelators in an aqueous medium. In turn, one hydrogelator was studied for the encapsulation and release of naproxen and chloroquine. The hydrogel exhibited sustained drug release over a period of several days, with the release of chloroquine being faster at lower pH due to the acid lability of the gelator molecule. The synthesis, characterization, gelation properties, and studies on drug diffusion are discussed. Acetal ; Chemistry ; Aqueous solution ; Self-healing hydrogels ; Solvent ; Organic chemistry ; Protecting group ; Drug delivery ; Carbamate ; Combinatorial chemistry ; Hydrogen bond ; Molecule Supramolecular Self-Assembly in Materials ; RNA Interference and Gene Delivery ; Lipid Membrane Structure and Behavior
Authors: R. T. Birla Sheyara | P. Ramar | Muthu Satheeshkumar | B. V. N. Phani Kumar | Debasis Samanta
Source: Chemistry - An Asian Journal (article, 2023-04-21)
Field: Materials Science — Surfaces, Coatings and Films

Transparent Superhydrophobic Coatings of Silica Nanoparticles Using Functionalized Polyurethanes Superhydrophobic coatings are essential to prepare water-repellent surfaces, self-cleaning materials, etc. Silica nano-materials are often immobilized to different surfaces for imparting super-hydrophobicity. Direct coating of silica-nanoparticles is often challenging since it can easily be peeled off under different environments. Herein, we reported the use of properly functionalized polyurethanes to facilitate the strong binding of silica-nanoparticles to surfaces. The alkyne terminal polyurethane was synthesized by step-growth polymerization while click-reactions facilitated to post-functionalization using phenyl moiety and were characterized by <sup>1</sup> H, <sup>13</sup> C nuclear magnetic resonance (NMR) spectroscopies, and <sup>1</sup> H spin-lattice relaxation times (T<sub>1</sub> s). Upon functionalization, the glass transition temperature (Tg) increased due to enhanced interchain interactions. Moreover, additives like di(propyleneglycol)dibenzoate showed a substantial plasticizing effect to compensate for the increase in Tg, an important parameter for low-temperature applications. NMR signatures the spatial interactions between various protons of grafted silica-nanoparticles and phenyl triazole functionalized polyurethanes, thus indicating the usefulness of polyurethanes to bind silica-nanoparticles. After coating functionalized silica-nanoparticles to leather using functionalized polyurethanes, a contact angle value of more than 157° was observed with retention of grain patterns of leather due to transparency. We anticipate the results to help design varieties of materials with superhydrophobicity where the structural integrity of the surfaces is retained. Materials science ; Contact angle ; Surface modification ; Nanoparticle ; Polyurethane ; Coating ; Chemical engineering ; Moiety ; Polymerization ; Glass transition ; Nanotechnology ; Polymer chemistry ; Polymer ; Composite material ; Organic chemistry ; Chemistry Surface Modification and Superhydrophobicity ; Advanced Sensor and Energy Harvesting Materials ; Luminescence and Fluorescent Materials
Authors: Kathrin Kostka | Matthias Epple
Source: Chemistry (article, 2023-05-07)
Field: Materials Science — Biomaterials

Surface Functionalization of Calcium Phosphate Nanoparticles via Click Chemistry: Covalent Attachment of Proteins and Ultrasmall Gold Nanoparticles Calcium phosphate nanoparticles (60 nm) were stabilized with either polyethyleneimine (PEI; polycationic electrolyte) or carboxymethylcellulose (CMC; polyanionic electrolyte). Next, a silica shell was added and terminated with either azide or alkyne groups via siloxane coupling chemistry. The particles were covalently functionalized by copper-catalyzed azide-alkyne cycloaddition (CuAAC; click chemistry) with proteins or gold nanoparticles that carried the complementary group, i.e., either alkyne or azide. The model proteins hemoglobin and bovine serum albumin (BSA) were attached as well as ultrasmall gold nanoparticles (2 nm). The number of protein molecules and gold nanoparticles attached to each calcium phosphate nanoparticle was quantitatively determined by extensive fluorescent labelling and UV–Vis spectroscopy on positively (PEI) or negatively (CMC) charged calcium phosphate nanoparticles, respectively. Depending on the cargo and the nanoparticle charge, this number was in the range of several hundreds to thousands. The functionalized calcium phosphate particles were well dispersible in water as shown by dynamic light scattering and internally amorphous as shown by X-ray powder diffraction. They were easily taken up by HeLa cells and not cytotoxic. This demonstrates that the covalent surface functionalization of calcium phosphate nanoparticles is a versatile method to create transporters with firmly attached cargo molecules into cells. Surface modification ; Nanoparticle ; Dynamic light scattering ; Click chemistry ; Colloidal gold ; Chemistry ; Triethoxysilane ; Covalent bond ; Azide ; Bovine serum albumin ; Combinatorial chemistry ; Polymer chemistry ; Materials science ; Organic chemistry ; Nanotechnology ; Biochemistry Nanoparticle-Based Drug Delivery ; Advanced biosensing and bioanalysis techniques ; Click Chemistry and Applications
Authors: Motomu Tanaka | Marie Pierre Krafft | Andréea Pasc
Source: NPG Asia Materials (article, 2023-04-21)
Field: Chemistry — Organic Chemistry

Higher-order mesoscopic self-assembly of fluorinated surfactants on water surfaces Abstract Surfactants containing fluorocarbon chains have been increasingly studied because they self-assemble into a variety of microscopic and mesoscopic domains and tend to form highly ordered patterns at the air/water interface; these patterns are clearly different from those formed by their hydrocarbon analogs. Focusing on the fluorinated surfactants possessing unique physical characteristics, this review describes the relationship between the line tension and dipole interaction, which is the comprehensive principle governing the pattern formation of two-dimensional self-assemblies. This review further discusses several key experimental and analytical techniques that are useful for characterizing the shape, size, correlation, and viscoelasticity of hierarchical self-assemblies on water surfaces. Finally, several biomedical applications, including biomimetic surface coating, multimodal contrast agents in medical diagnostics, and controlled delivery of gases (O 2 and NO) for oxygenation and antimicrobial effects, are introduced to highlight how the unique physicochemical properties of fluorinated self-assemblies can be applied in materials science. Mesoscopic physics ; Materials science ; Nanotechnology ; Surface tension ; Coating ; Self-assembly ; Fluorocarbon ; Chemical physics ; Chemical engineering ; Composite material ; Chemistry Surfactants and Colloidal Systems ; Surface Modification and Superhydrophobicity ; Polymer Surface Interaction Studies
Authors: Domen Paul | Miran Mozetič | Rok Zaplotnik | Jernej Ekar | Alenka Vesel | Gregor Primc | Denis Đonlagić
Source: Materials (article, 2023-08-24)
Field: Materials Science — Materials Chemistry

Loss of Oxygen Atoms on Well-Oxidized Cobalt by Heterogeneous Surface Recombination Calorimetry is a commonly used method in plasma characterization, but the accuracy of the method is tied to the accuracy of the recombination coefficient, which in turn depends on a number of surface effects. Surface effects also govern the kinetics in advanced methods such as atomic layer oxidation of inorganic materials and functionalization of organic materials. The flux of the reactive oxygen atoms for the controlled oxidation of such materials depends on the recombination coefficient of materials placed into the reaction chamber, which in turn depends on the surface morphology, temperature, and pressure in the processing chamber. The recombination coefficient of a well-oxidized cobalt surface was studied systematically in a range of temperatures from 300 to 800 K and pressures from 40 to 200 Pa. The coefficient increased monotonously with decreasing pressure and increasing temperature. The lowest value was about 0.05, and the highest was about 0.30. These values were measured for cobalt foils previously oxidized with oxygen plasma at the temperature of 1300 K. The oxidation caused a rich morphology with an average roughness as deduced from atomic force images of 0.9 µm. The results were compared with literature data, and the discrepancy between results reported by different authors was explained by taking into account the peculiarities of their experimental conditions. Cobalt ; Oxygen ; Materials science ; Recombination ; Surface roughness ; Analytical Chemistry (journal) ; Kinetics ; Surface modification ; Calorimetry ; Atmospheric temperature range ; Plasma ; Chemistry ; Thermodynamics ; Physical chemistry ; Composite material ; Metallurgy ; Organic chemistry Diamond and Carbon-based Materials Research ; Metal and Thin Film Mechanics ; Plasma Diagnostics and Applications
Authors: Jingwen Xia | Tetyana V. Koso | Katja Heise | Lukas Fliri | Emilie Ressouche | Johanna Majoinen | Mauri A. Kostiainen | Sami Hietala | Michael Hummel | Vladimir Aseyev | Ilkka Kilpeläinen | Alistair W. T. King
Source: Chemical Communications (article, 2023-01-01)
Field: Materials Science — Biomaterials

Stable glycosylamines at the reducing ends of cellulose nanocrystals The reaction of reducing end groups in cellulose nanocrystals with dodecylamine was examined. Using a direct-dissolution solution-state NMR protocol, the regioselective formation of glucosylamines was shown. This provides an elegant approach to sustainably functionalize these bio-based nanomaterials, that may not require further reduction to more stable secondary amines. Cellulose ; Nanocrystal ; Chemistry ; Materials science ; Combinatorial chemistry ; Nanotechnology ; Organic chemistry Advanced Cellulose Research Studies ; Polysaccharides and Plant Cell Walls ; Biofuel production and bioconversion
Authors: Kana Takebayashi | Arihiro Kanazawa | Sadahito Aoshima
Source: Polymer Journal (article, 2023-11-10)
Field: Materials Science — Biomaterials

Cationic ring-opening copolymerization of a cyclic acetal and γ-butyrolactone: monomer sequence transformation and polymerization–depolymerization control by vacuuming or temperature changes Abstract Polymerization–depolymerization equilibrium is a promising strategy for the construction of polymerization systems through which sustainable polymers can undergo reversible polymer–monomer transformations. In this study, we perform monomer sequence transformation and copolymer depolymerization, which are based on transacetalization reactions and polymerization–depolymerization equilibrium, in the cationic ring-opening copolymerization of 2-methyl-1,3-dioxepane and γ-butyrolactone with a protonic acid. The removal of monomer molecules from the copolymerization solution by vacuuming with a vacuum pump caused monomer sequence to transform into pseudo-alternating copolymer chains and subsequently depolymerize into oligomers. Increasing the temperature during copolymerization also resulted in depolymerization, while copolymers were regenerated by the subsequent decrease in temperature. Depolymerization ; Cationic polymerization ; Copolymer ; Monomer ; Polymer chemistry ; Polymerization ; Polymer ; Chemistry ; Ring-opening polymerization ; Materials science ; Organic chemistry biodegradable polymer synthesis and properties ; Carbon dioxide utilization in catalysis ; Advanced Polymer Synthesis and Characterization
Authors: Frédéric Dumur
Source: Macromol—A Journal of Macromolecular Research (article, 2023-04-23)
Field: Chemistry — Organic Chemistry

Recent Advances on Glyoxylates and Related Structures as Photoinitiators of Polymerization The design of photoinitiators activable under low-light intensity is an active research field, supported by the recent energetic sobriety plans imposed by numerous countries in Europe. With an aim to simplify the composition of the photocurable resins, Type I photoinitiators are actively researched as these structures can act as monocomponent systems. In this field, a family of structures has been under-investigated at present, namely, glyoxylates. Besides, the different works carried out in three years have evidenced that glyoxylates and related structures can be versatile for the design of Type I photoinitiators. In this review, an overview of the different glyoxylates and related structures reported to date is provided. Photopolymer ; Photoinitiator ; Polymerization ; Sobriety ; Materials science ; Nanotechnology ; Polymer science ; Computer science ; Polymer ; Composite material ; Monomer Photopolymerization techniques and applications ; Advanced Polymer Synthesis and Characterization ; Dental materials and restorations
Authors: А. А. Спасов | I.G. Ovchinnikova | О. В. Федорова | Yu. A. Titova | Denis A. Babkov | В. А. Косолапов | А. В. Борисов | E. V. Sokolova | Vladlen Klochkov | Maria O. Skripka | Yu. I. Velikorodnaya | А. В. Смирнов | Gennady L. Rusinov | Valery N. Charushin
Source: Molecules (article, 2023-01-11)
Field: Chemistry — Organic Chemistry

Amino Derivatives of Diaryl Pyrimidines and Azolopyrimidines as Protective Agents against LPS-Induced Acute Lung Injury The problem of lung damage originating from excessive inflammation and cytokine release during various types of infections remains relevant and stimulates the search for highly effective and safe drugs. The biological activity of the latter may be associated with the regulation of hyperactivation of certain immune cells and enzymes. Here, we propose the design and synthesis of amino derivatives of 4,6- and 5,7-diaryl substituted pyrimidines and [1,2,4]triazolo[1,5-<i>a</i>]pyrimidines as promising double-acting pharmacophores inhibiting IL-6 and NO. The anti-inflammatory activity of 14 target compounds was studied on isolated primary murine macrophages after LPS stimulation. Seven compounds were identified to inhibit the synthesis of nitric oxide and interleukin 6 at a concentration of 100 µM. The most active compounds are micromolar inhibitors of IL-6 secretion and NO synthesis, showing a minimal impact on innate immunity, unlike the reference drug dexamethasone, along with acceptable cytotoxicity. Evaluation in an animal model of acute lung injury proved the protective activity of compound <b>6e</b>, which was supported by biochemical, cytological and morphological markers. Pharmacophore ; Nitric oxide ; Cytotoxicity ; Pharmacology ; Chemistry ; Inflammation ; Drug ; Immune system ; Cytokine ; Secretion ; Dexamethasone ; Amino acid ; Biochemistry ; Immunology ; Medicine ; In vitro ; Internal medicine Synthesis and biological activity ; Quinazolinone synthesis and applications ; Synthesis of heterocyclic compounds
Authors: Ricky Andi Syahputra | Zulmai Rani | R. Ridwanto | Dikki Miswanda | A. F. Pulungan
Source: RASAYAN Journal of Chemistry (article, 2023-01-01)
Field: Chemistry — Organic Chemistry

ISOLATION AND CHARACTERIZATION OF GLYCEROL BY TRANSESTERIFICATION OF USED COOKING OIL Used cooking oil is oil that comes from two or more frying food ingredients. This used cooking oil produces methyl esters with glycerol as a by-product through a transesterification reaction. The goal of this study was to convert and utilize used cooking oil into glycerol, as well as to demonstrate the similarity of functional groups and components found in commercial glycerol using IR and GC-MS spectroscopy. The results of the study found that using cooking oil glycerol and commercial glycerol showed that there were similarities in the 1,2,3 propanetriol groups with retention times that were close to 9.6-10.3 minutes and 9.6-10.13 minutes. The IR spectrum showed the presence of OH, CH, C=O, and C-O groups as well as those found in commercial glycerol, and the glycerol content obtained was 90.17% Glycerol ; Transesterification ; Chemistry ; Food science ; Organic chemistry ; Cooking oil ; Biodiesel ; Catalysis Edible Oils Quality and Analysis ; Agricultural and Biological Research