jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Faruq Mohammad | Hamad A. Al‐Lohedan | Payal B. Joshi | Prasanna Kumar Obulapuram | Murthy Chavali | Aiesha Nawaf Al-Balawi | Maria P. Nikolova
Source: Precision Nanomedicine (article, 2022-08-10)
Field: Materials Science — Materials Chemistry

Engineered superparamagnetic iron oxide nanoparticles for externally controlled hyperthermia, drug delivery, and therapeutic toxicity &lt;img src=” https://s3.amazonaws.com/production.scholastica/article/37603/large/prnano_832022ga.jpg?1660747427”&gt; Nanotechnology and materials science are highly developing sectors where several new materials are investigated. One area includes iron oxide nanoparticles with superparamagnetic behavior. Since nanomaterials are prone to be associated with high levels of intrinsic toxicity and can have adverse effects if not properly guided. So, toxic mechanisms associated with nanomaterials are like that of a therapeutic drug or any other toxic compound. In that way, by ignoring the general pathways of cell death followed by the nanomaterials, the present report covers the points to control the growth of cancer cells by employing engineered nanoparticles (NPs) to induce therapeutic toxicity. We discuss the pathways for the induction of toxicity to the cancer cells using the superparamagnetic iron oxide nanoparticles (SPIONs) with and without surface ligands, and the ligand efficiency towards controlling toxicity is covered. Also, the therapeutic means of controlling the cancer cells, such as generating heat and releasing anticancer drugs in an externally organized manner, are also discussed. Overall, the report links the physical properties of SPIONs related to their natural or therapeutical toxicity by connecting physicochemical and toxicology principles. Toxicity ; Nanomaterials ; Nanotechnology ; Nanoparticle ; Drug delivery ; Chemistry ; Drug ; Superparamagnetism ; Targeted drug delivery ; Pharmacology ; Materials science ; Medicine ; Organic chemistry Nanoparticles: synthesis and applications ; Nanoparticle-Based Drug Delivery ; Graphene and Nanomaterials Applications
Authors: Getachew Alemu Anshebo | Ataklti Abraha Gebreyohanes
Source: Journal of Nanomaterials (article, 2022-01-01)
Field: Chemistry — Electrochemistry

Investigation on Dye Regeneration Kinetics at P‐Type Sensitized Nanoparticle Nickel Oxide Film by Scanning Electrochemical Microscopy The efficiency of a NiO‐sensitized solar cell is determined by the kinetics of hole injection and dye regeneration reactions at the NiO/dye/electrolyte interface. In this research, the photochemical regeneration kinetics of dye adsorbed on the NiO film was investigated by scanning electrochemical microscopy (SECM). Besides, organic C343 and P1 sensitizers in combination with iodide‐based, cobalt‐based, and thiolate‐based electrolytes were selected to understand the effect of sensitizers and redox shuttles on the dye regeneration process. As a result, a fast regeneration kinetic rate constant was conformed in the thiolate‐based sample compared with cobalt‐based and iodide‐based, demonstrating that the organic redox shuttle was an efficient mediator to optimize the performance of p‐type DSSC. Furthermore, the regeneration rate constants ( k eff ), reduction rate constants ( k red ), and absorption cross section ( Ф hv ) were investigated for organic dyes and electrolytes. That is, an effective dye regeneration rate constant k red of 6.95 × 10 5 mol -1 cm 3 s -1 for NiO/P1 and k red of 3.75 × 10 5 mol -1 cm 3 s -1 for NiO/C343 was found at various wavelengths. Therefore, the experimental results demonstrate that regeneration kinetics are dependent on the type of electrolyte and dye used. Moreover, the results suggest that scanning electrochemical microscopy is a powerful method for screening efficient dyes and electrolytes for charge transfer reactions in P‐type dye‐sensitized solar cells. Non-blocking I/O ; Reaction rate constant ; Materials science ; Kinetics ; Scanning electrochemical microscopy ; Iodide ; Electrolyte ; Electrochemistry ; Scanning electron microscope ; Nickel oxide ; Redox ; Supporting electrolyte ; Analytical Chemistry (journal) ; Nuclear chemistry ; Nickel ; Physical chemistry ; Inorganic chemistry ; Electrode ; Chemistry ; Organic chemistry ; Physics ; Catalysis ; Composite material ; Metallurgy Electrochemical Analysis and Applications ; TiO2 Photocatalysis and Solar Cells ; Analytical Chemistry and Sensors
Authors: Mahmoud A. Sliem | Ahmed Youssef Salim | Rana M. Abdelnaby | Gehad G. Mohamed | Alaa S. Amin
Source: Benha Journal of Applied Sciences (article, 2022-12-01)
Field: Chemistry — Electrochemistry

Photocatalytic Degradation of Naphthalene in Aqueous Dispersion of Nanoparticles: Effect of Different Parameters Contamination with naphthalene, as one of polycyclic aromatic hydrocarbons (PAHs), was considered as an important health issue due to its mutagenic and carcinogenic potential . In this essay, we focused on the photo catalytic degradation of naphthalene in various mediaand in presence of various photocatalysts. Zinc oxide nanoparticles (ZnO NPs) was prepared and utilized as efficient photocatalyst to convert naphthalene into safer compounds. Transmission electron microscopy (TEM), UV-VIS spectroscopy and x-ray diffraction (XRD) were used to evaluate the photocatalyst in its as-prepared state. The length of the photocatalytic degradation process, the amount of loading catalyst and the intensity of the light are all influencing variables, were investigated. The optimum photocatalytic degradation of 21.53 mg/L naphthalene in different media was carried out at pH 12 with maximum loading catalyst dose of 666.666 mg/L. In case of naphthalene aqueous ethanolic solution, a faster photochemical kinetic was observed in presence of ZnO NPs and more than 90% of photocatalytic degradation percentage was reached in 395 min. Gas chromatography-mass spectrometry was used to identify the byproducts of butyl phthalate (95.38%). (GC–MS). The results of the kinetic studies showed that the pseudo-first order rate expression and Langmuir-Hinshelwood model were both used to describe the photocatalytic degradation process. Naphthalene ; Photocatalysis ; Degradation (telecommunications) ; Nanoparticle ; Aqueous solution ; Dispersion (optics) ; Chemical engineering ; Materials science ; Chemistry ; Nanotechnology ; Catalysis ; Organic chemistry ; Computer science ; Optics Electrochemical Analysis and Applications ; Chemistry and Chemical Engineering ; TiO2 Photocatalysis and Solar Cells
Authors: Ruben Van Lommel | Julie Van Hooste | Johannes Vandaele | Gert Steurs | Tom Van der Donck | Frank De Proft | Susana Rocha | Dimitrios Sakellariou | Mercedes Alonso | Wim M. De Borggraeve
Source: Gels (article, 2022-12-10)
Field: Materials Science — Biomaterials

Does Supramolecular Gelation Require an External Trigger? The supramolecular gelation of small molecules is typically preceded by an external stimulus to trigger the self-assembly. The need for this trigger stems from the metastable nature of most supramolecular gels and can limit their applicability. Herein, we present a small urea-based molecule that spontaneously forms a stable hydrogel by simple mixing without the addition of an external trigger. Single particle tracking experiments and observations made from scanning electron microscopy indicated that triggerless gelation occurred in a similar fashion as the archetypical heat-triggered gelation. These results could stimulate the search for other supramolecular hydrogels that can be obtained by simple mixing. Furthermore, the mechanism of the heat-triggered supramolecular gelation was elucidated by a combination of molecular dynamics simulations and quantitative NMR experiments. Surprisingly, hydrogelation seemingly occurs via a stepwise self-assembly in which spherical nanoparticles mature into an entangled fibrillary network. Supramolecular chemistry ; Metastability ; Self-healing hydrogels ; Chemical physics ; Molecule ; Nanotechnology ; Materials science ; Supramolecular polymers ; Chemical engineering ; Chemistry ; Polymer chemistry ; Organic chemistry Supramolecular Self-Assembly in Materials ; Supramolecular Chemistry and Complexes ; Metal-Organic Frameworks: Synthesis and Applications
Authors: Khalid Azyat | Darren Makeiff | Bradley D. Smith | Mickie Wiebe | Steve Launspach | Ashley Wagner | Marianna Kulka | Nicolas Godbert
Source: Gels (article, 2022-12-22)
Field: Materials Science — Biomaterials

The Effect of Branched Alkyl Chain Length on the Properties of Supramolecular Organogels from Mono-N-Alkylated Primary Oxalamides Mono-<i>N</i>-alkylated primary oxalamide derivatives with different sized branched alkyl tail-groups were excellent low molecular weight gelators for a variety of different organic solvents with different polarities and hydrogen-bonding abilities. Solvent-gelator interactions were analyzed using Hansen solubility parameters, while <sup>1</sup>H NMR and FTIR spectroscopy were used to probe the driving forces for the supramolecular gelation. The molecular structures of the twin tail-groups did not significantly affect the supramolecular gelation behavior in different solvents. However, for select solvents, the molecular structures of the tail-groups did have a significant effect on gel properties such as the critical gelator concentration, thermal stability, gel stiffness, gel strength, network morphology, and molecular packing. Finally, metabolic activity studies showed that the primary alkyl oxalamide gelators had no effect on the metabolic activity of mouse immune cells, which suggests that the compounds are not cytotoxic and are suitable for use in biomedical applications. Alkyl ; Supramolecular chemistry ; Solubility ; Thermal stability ; Solvent ; Hydrogen bond ; Alkylation ; Fourier transform infrared spectroscopy ; Chemistry ; Primary (astronomy) ; Molecule ; Polymer chemistry ; Proton NMR ; Organic chemistry ; Materials science ; Chemical engineering Supramolecular Self-Assembly in Materials ; RNA Interference and Gene Delivery ; Neuropeptides and Animal Physiology
Authors: Yudai Tominaga | Sayuki Kanemitsu | Shota Yamamoto | Toshihisa Kimura | Yuki Nishida | Kenta Morita | Tatsuo Maruyama
Source: Colloids and Surfaces A Physicochemical and Engineering Aspects (article, 2022-10-20)
Field: Materials Science — Biomaterials

Thermally irreversible supramolecular hydrogels record thermal history Self-healing hydrogels ; Supramolecular chemistry ; Amphiphile ; Polymer chemistry ; Covalent bond ; Alkyl ; Dynamic covalent chemistry ; Materials science ; Chemistry ; Chemical engineering ; Organic chemistry ; Molecule ; Polymer ; Copolymer Supramolecular Self-Assembly in Materials ; Polydiacetylene-based materials and applications ; Photochromic and Fluorescence Chemistry
Authors: Pankaj Yadav | Krupa Shah | Krupa Kansara | Subhajit Das | Ashutosh Kumar | Rakesh Rawal | Dhiraj Bhatia
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2022-04-23)
Field: Materials Science — Materials Chemistry

Green emitting carbon quantum dots (GCQDs) to probe endocytic pathways in cells; for tissue and <i>in vivo</i> bioimaging Abstract Small sized, carbon-based organic nanoparticles have recently gained attention due their advantage of biocompatibility, photostability and biological non-toxicity as compared to their inorganic counterparts. Herein, a new class of small (5-8 nm), green emitting fluorescent carbon quantum dots (GCQDs) were synthesized using organic substrates like citric acid and ascorbic acid in aqueous solvent containing water and ethanol. The very small size and bright green photoluminescence prompted their use for both in vitro and in vivo bioimaging. GCQDs were uptaken via clathrin mediated pathways in mouse kidney and liver primary cells. Similarly, they showed active uptake and distribution in the zebrafish embryo model system. The optical tunability and surface modification properties of these GCQDs provide a platform to be explored for them to emerge as a new class of targeted bioimaging entities, as well as tools for biomedical applications. Biocompatibility ; Nanotechnology ; In vivo ; Photoluminescence ; Fluorescence ; Quantum dot ; Carbon quantum dots ; Materials science ; Chemistry ; Surface modification ; Ascorbic acid ; Biophysics ; Biology ; Organic chemistry ; Optoelectronics Carbon and Quantum Dots Applications ; Nanocluster Synthesis and Applications ; Quantum Dots Synthesis And Properties
Authors: C. Sermsrithong | P. Jaidaew | Chamnan Promjantuk | Pakpoom Buabthong
Source: International Journal of Engineering (article, 2022-01-01)
Field: Materials Science — Materials Chemistry

Structural and Optical Properties of Bismuth-doped ZnO Nanoparticles Synthesized by Co-precipitation Bismuth-doped zinc oxide (ZnO) nanoparticles can serve as efficient photocatalysts for various reactions. Herein, we synthesized and discussed the growth mechanisms of Bi-doped ZnO nanoflakes using co-precipitation with Bi concentrations ranging from 0 to 3 %. The resulting ZnO were hexagonal nanosheets with diameters ranging from 80 nm (ZnO) to 200 nm (ZnO: Bi 3%). The dominant crystal structure matches hexagonal wurtzite with a small presence of Bi2O3 diffraction peaks. The estimated crystallite sizes range from ~ 33 nm to ~ 45 nm, indicating multiple crystalline regions in each nanoflake. Nevertheless, as sheet resistance monotonically decreases with the Bi concentration, the higher number of grain boundaries likely has a lower effect on the conductivity compared to an increase in free carriers and larger grain size in the samples with higher Bi concentration. The bandgap decreases from ~ 3.13 eV to ~ 2.96 eV, likely due to the shrinkage effect from electron-electron or electron-impurity interaction that lowers the conduction band of ZnO. Wurtzite crystal structure ; Materials science ; Crystallite ; Bismuth ; Band gap ; Nanoparticle ; Doping ; Precipitation ; Zinc ; Impurity ; Grain size ; Chemical engineering ; Nanotechnology ; Metallurgy ; Optoelectronics ; Chemistry ZnO doping and properties ; Ga2O3 and related materials ; Gas Sensing Nanomaterials and Sensors
Authors: Mónica Andrea Vargas | Lorena Marín | Winny Mónica Castillo | Luis Alfredo Rodríguez | César Magén | Milton Manotas-Albor | J.E. Diosa | Katherine L. Gross
Source: Preprints.org (preprint, 2022-05-11)
Field: Materials Science — Materials Chemistry

Effect of Ethylene Glycol:Citric Acid Molar Ratio and pH on the Morphology, Vibrational, Optical and Electronic Properties of TiO2 and CuO Powders Synthesized by Pechini Method High purity TiO2 and CuO powders were synthesized by the Pechini method, an inexpensive and easy-to-implement procedure to synthetize metal oxides. The variables of synthesis were the ethylene glycol:citric acid molar ratio and the pH. High reproducibility of the anatase and tenorite phase was obtained for all synthesis routes. The degree of purity of the powders was confirmed by XRD, FTIR, UV-vis absorption and XPS spectra. SEM and TEM images revealed the powders are composed by micrometer grains that can have a spherical shape (only in the TiO2) or formed by a non-compacted nanocrystalline conglomerate. FTIR spectra only vibrational modes associated to the TiO2 or CuO with a nanoparticle behavior. UV-vis absorption spectra revealed the values of maximum absorbance percentage of both systems are reached in the ultraviolet region, with percentages above 83 % throughout the entire visible light spectrum for the CuO system, a relevant result for solar cell applications. Finally, XPS experiments allow the observation of the valence bands and the calculation of the energy bands of all oxides. Ethylene glycol ; Nanocrystalline material ; X-ray photoelectron spectroscopy ; Materials science ; Fourier transform infrared spectroscopy ; Anatase ; Absorbance ; Citric acid ; Valence (chemistry) ; Analytical Chemistry (journal) ; Absorption spectroscopy ; Visible spectrum ; Chemical engineering ; Nuclear chemistry ; Nanotechnology ; Chemistry ; Photocatalysis ; Organic chemistry ; Optics ; Catalysis Copper-based nanomaterials and applications ; ZnO doping and properties
Authors: J.L. Hall | Clayton Bevas | Steven J. Hinder | Emily L. Kynaston | Christopher I. Lindsay | Patrick Gruber | Joseph L. Keddie
Source: Frontiers in Mechanical Engineering (article, 2022-01-18)
Field: Materials Science — Surfaces, Coatings and Films

Environmental Effects on the Coefficient of Friction and Tack Adhesion of Formulated Waterborne Coatings Waterborne coatings emit a low amount of harmful volatile organic compounds (VOCs) into the atmosphere compared to solvent-cast coatings. A typical waterborne formulation for agricultural applications consists of colloidal thermoplastic particles (latex) as the binder, a thickener to raise the viscosity, inorganic filler particles with a water-soluble dispersant, and a colloidal wax to modify surface properties. The formulations typically contain hygroscopic species that are potentially subject to softening by environmental moisture. The hardness, tack adhesion, and coefficient of friction of formulated coatings determines their suitability in applications. However, the relationship of these properties to the components in a coating formulation has not been adequately explored. Furthermore, the relationship between hygroscopic components and properties is an added complication. Here, we have characterized the hardness and tack adhesion of model formulated coatings using a single micro-indentation cycle with a conical indenter under controlled temperatures (above and below the glass transition temperature of a latex binder) and relative humidities. In parallel, we measured the coefficient of kinetic friction, μ k , for the same coatings using a bespoke testing rig under controlled environmental conditions. Across a range of temperatures, RH and compositions, we find an inverse correlation between the coating hardness and μ k . Any correlation of μ k with the roughness of the coatings, which varies with the composition, is less clear. Formulations that contain wax additives have a higher μ k at a low RH of 10%, in comparison to formulations without wax. For the wax formulations, μ k decreases when the RH is raised, whereas in non-wax formulations, μ k increases with increasing RH. Wax-containing coatings are hydrophilic (with a lower water contact angle), however the wax has a lower water permeability. A lubricating layer of water can explain the lower observed μ k in these formulations. The addition of wax is also found to planarize the coating surface, which leads to higher tack adhesion in dry coatings in comparison to coatings without wax. Greater adhesive contact in these coatings can explain their higher friction. Our systematic research will aid the design of seed coating formulations to achieve their optimum properties under a wide range of environmental conditions. Materials science ; Wax ; Composite material ; Coating ; Adhesion ; Zinc stearate ; Glass transition ; Polymer ; Raw material ; Chemistry Surface Modification and Superhydrophobicity ; Adhesion, Friction, and Surface Interactions ; Tribology and Wear Analysis
Authors: Caterina Damiano | Matteo Cavalleri | Nicola Panza | Emma Gallo
Source: European Journal of Organic Chemistry (article, 2022-08-15)
Field: Chemistry — Organic Chemistry

Cobalt Porphyrin‐Catalysed Synthesis of Azobenzenes by Dehydrogenative Coupling of Anilines Abstract The demand for azobenzenes has exponentially grown due to their wide range of applications in textile, medical, and dye industries. Here we report a procedure to synthesise azobenzenes by the dehydrogenative coupling of anilines in the presence of Co II (TPP) (TPP=dianion of tetraphenyl porphyrin) catalyst and 4‐nitrophenyl azide oxidant species. Differently substituted azobenzenes were obtained in yields up to 72 % together with 4‐nitrophenyl amine, which is the stoichiometric by‐product of the process. The procedure displayed a good sustainability due to the almost quantitative recovery of pure 4‐nitrophenyl amine that can be transformed again into the desired azide to pave the way for an efficient circular process. Experimental data supported the occurrence of a radical mechanism mediated by putative nitrene radical cobalt intermediate. Chemistry ; Porphyrin ; Azide ; Cobalt ; Nitrene ; Amine gas treating ; Catalysis ; Photochemistry ; Combinatorial chemistry ; Polymer chemistry ; Organic chemistry Radical Photochemical Reactions ; Photochromic and Fluorescence Chemistry ; Synthesis and Catalytic Reactions
Authors: Mina Vaez | Meisam Asgari | L Hirvonen | Görkem Bakir | Sebastián Aguayo | C. Schuh | Kathleen Gough | Laurent Bozec
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2022-03-03)
Field: Materials Science — Biomaterials

Modulation of the Biophysical and Biochemical Properties of Collagen by Glycation for Tissue Engineering Applications Abstract The structural and functional properties of collagen are modulated by the presence of intramolecular and intermolecular crosslinks. Advanced Glycation End-products (AGEs) can produce intermolecular crosslinks by bonding the free amino groups of neighboring proteins. In this research, the following hypothesis is explored: The accumulation of AGEs in collagen decreases its proteolytic degradation rates while increasing its stiffness. Fluorescence Lifetime Imaging (FLIM) and Fourier-transform infrared spectroscopy (FTIR) detect biochemical changes in collagen scaffolds during the glycation process. The accumulation of AGEs increases exponentially in the collagen scaffolds as a function of Methylglyoxal (MGO) concentration by performing autofluorescence measurement and competitive ELISA. Glycated scaffolds absorb water at a much higher rate confirming the direct affinity between AGEs and interstitial water within collagen fibrils. In addition, the topology of collagen fibrils as observed by Atomic Force Microscopy (AFM) is a lot more defined following glycation. The elastic modulus of collagen fibrils decreases as a function of glycation, whereas the elastic modulus of collagen scaffolds increases. Finally, the enzymatic degradation of collagen by bacterial collagenase shows a sigmoidal pattern with a much slower degradation rate in the glycated scaffolds. This study identifies unique variations in the properties of collagen following accumulation of AGEs. Glycation ; Chemistry ; Biophysics ; Collagenase ; Type I collagen ; Pentosidine ; Autofluorescence ; Fourier transform infrared spectroscopy ; Fibrillogenesis ; Elastic modulus ; Fibril ; Biochemistry ; Chemical engineering ; Fluorescence ; Materials science ; Enzyme ; Composite material Collagen: Extraction and Characterization ; Advanced Glycation End Products research ; Protein Hydrolysis and Bioactive Peptides