jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Arundhati Joshi | Hendrik Naatz | Kathrin Faber | Suman Pokhrel | Ralf Dringen
Source: Neurochemical Research (article, 2020-01-29)
Field: Chemistry — Electrochemistry

Iron-Doping of Copper Oxide Nanoparticles Lowers Their Toxic Potential on C6 Glioma Cells Copper oxide nanoparticles (CuO-NPs) are well known for their cytotoxicity which in part has been attributed to the release of copper ions from CuO-NPs. As iron-doping has been reported to reduce the susceptibility of CuO-NPs to dissolution, we have compared pure CuO-NPs and CuO-NPs that had been doped with 10% iron (CuO-Fe-NPs) for copper release and for their toxic potential on C6 glioma cells. Physicochemical characterization revealed that dimercaptosuccinate (DMSA)-coated CuO-NPs and CuO-Fe-NPs did not differ in their size or zeta potential. However, the redox activity and liberation of copper ions from CuO-Fe-NPs was substantially slower compared to that from CuO-NPs, as demonstrated by cyclic voltammetry and by the photometric quantification of the copper ion-bathocuproine complex, respectively. Exposure of C6 cells to these NPs caused an almost identical cellular copper accumulation and each of the two types of NPs induced ROS production and cell toxicity. However, the time- and concentration-dependent loss in cell viability was more severe for cells that had been treated with CuO-NPs compared to cells exposed to CuO-Fe-NPs. Copper accumulation and toxicity after exposure to either CuO-NPs or CuO-Fe-NPs was prevented in the presence of copper chelators, while neutralization of the lysosomal pH by bafilomycin A1 prevented toxicity without affecting cellular copper accumulation or ROS production. These data demonstrate that iron-doping does not affect cellular accumulation of CuO-NPs and suggests that the intracellular liberation of copper ions from CuO-NPs is slowed by the iron doping, which in turn lowers the cell toxic potential of iron-doped CuO-NPs. Copper ; Nanoparticle ; Zeta potential ; Chemistry ; Copper oxide ; Inorganic chemistry ; Copper toxicity ; Dissolution ; Nuclear chemistry ; Materials science ; Nanotechnology ; Organic chemistry Electrochemical Analysis and Applications ; Nanoparticles: synthesis and applications ; Gold and Silver Nanoparticles Synthesis and Applications
Authors: Yuto Shimoyama | Sayaka Uchida
Source: Chemistry Letters (article, 2020-09-24)
Field: Materials Science — Materials Chemistry

Structure-function Relationships of Porous Ionic Crystals (PICs) Based on Polyoxometalate Anions and Oxo-centered Trinuclear Metal Carboxylates as Counter Cations Abstract Unique structures and functions of porous ionic crystals (PICs) based on polyoxometalate (POM) anions, which are different from typical porous crystalline materials such as zeolites and metal-organic frameworks (MOFs), can be summarized as follows. (i) Crystal structures of PICs are often flexible since Coulomb interaction works isotropically in a long-range, so that structural transformation occurs to adapt to specific guest molecules. (ii) POMs show reversible redox properties leading to the formation of “redox-active” porous materials. (iii) Ionic building blocks create strong electrostatic fields in the pore, which are suitable for accommodating and stabilizing polar guests and ionic intermediates. (iv) Various cations can be incorporated as counter cations of POMs to fine-tune the functions. The crystal structures and functions of PICs can be controlled by the appropriate choice of molecular cations (macrocations) as ionic building blocks as well as the symmetry, size, and charge of POMs. In particular, oxo-centered trinuclear metal (MIII) carboxylates with a general formula of [M3O(OOCR)6(L)3]+ as macrocations allow controlling the crystal structures of PICs through the bridging ligands (R) and terminal ligands (L). The fine-tuned structures of PICs lead to unique functions in gas/solvent sorption/separation, heterogeneous catalysis, redox-induced ion-uptake/release, synthesis of mixed-valance metal nanoclusters, and so on. Polyoxometalate ; Chemistry ; Ionic bonding ; Redox ; Ionic compound ; Metal ; Crystal structure ; Crystallography ; Nanoclusters ; Solvent ; Molecule ; Inorganic chemistry ; Catalysis ; Ion ; Organic chemistry Polyoxometalates: Synthesis and Applications ; Metal-Organic Frameworks: Synthesis and Applications ; Covalent Organic Framework Applications
Authors: Sandhya Venkateshalu | Andrews Nirmala Grace
Source: Journal of The Electrochemical Society (article, 2020-01-04)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Review—Heterogeneous 3D Graphene Derivatives for Supercapacitors With the increasing industrialization and growing population, there is a great demand in developing efficient energy storage devices. One such device is a supercapacitor, which has been gaining attention in the past decade with its excellent energy and power density. By varying the electrode materials of the supercapacitor, its properties could be fine tuned to a greater extent. A heterogeneous functional material such as graphene is the widely used electrode material among the carbonaceous electrode materials. Graphene, a 2D structured material often suffers from agglomeration thereby limiting its performance. Restacking of sheets into a 3D structure enables them to provide numerous properties beneficial in improving the supercapacitance. This review focuses on the synthesis and application of various heterogeneous 3D graphene derivatives such as foam, sponge, aerogel, hydrogel, fibers, tubes, spheres etc., in supercapacitors. Supercapacitor ; Graphene ; Materials science ; Nanotechnology ; Aerogel ; Electrode ; Limiting ; Economies of agglomeration ; Energy storage ; Capacitance ; Chemical engineering ; Power (physics) ; Chemistry ; Mechanical engineering Supercapacitor Materials and Fabrication ; Electrospun Nanofibers in Biomedical Applications ; Graphene research and applications
Authors: Jooyeon Lee | Chinnadurai Satheeshkumar | Hyun Jung Yu | Seongwoo Kim | Jong Suk Lee | Myungeun Seo | Min Kim
Source: ACS Applied Nano Materials (article, 2020-07-27)
Field: Chemistry — Inorganic Chemistry

Pore Engineering of Covalently Connected Metal–Organic Framework Nanoparticle–Mixed-Matrix Membrane Composites for Molecular Separation Fine-tuning and pore environment control of covalently connected metal–organic framework (MOF) and mixed-matrix membrane (MMM) composite materials were achieved. Core–shell-type, dual-functionalized, zirconium-based MOFs were prepared through a postsynthetic ligand exchange (PSE) process, and active vinyl functionalities on the surface of MOF nanoparticles were utilized for polymerization by forming interfacial-covalent connections between MOF nanoparticles and polymeric membranes via thiol–ene click photopolymerization. The target functionality of the MOF pore originated from the parent MOFs, allowing pore engineering of the MOF–MMM composite materials. A series of defect-free, interface-controlled, and core-functionalized MOF–MMMs were prepared through the present methodology, and the NO2-functionalized/covalently connected MOF–MMM showed the highest CO2 permeability and solubility without loss of selectivity. This facile and versatile approach will be useful for the fabrication of functional MOF nanoparticle-based membranes for various applications, such as catalysis and separation. Covalent bond ; Materials science ; Membrane ; Nanoparticle ; Covalent organic framework ; Metal-organic framework ; Chemical engineering ; Hybrid material ; Composite number ; Polymerization ; Zirconium ; Polymer chemistry ; Polymer ; Nanotechnology ; Chemistry ; Composite material ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Covalent Organic Framework Applications ; Membrane Separation and Gas Transport
Authors: Massimo Lazzari | Mercedes Torneiro
Source: Polymers (review, 2020-04-10)
Field: Materials Science — Materials Chemistry

A Global View on Block Copolymers In this systematic review, a total of 45,143 publications on block copolymers, issued between 1952 and 2019, are analyzed in terms of number, source, language, institution, country, keywords, and block copolymer type, to find out their evolution and predict research trends. The number of publications devoted to block copolymers has been growing for over six decades, maintaining a consistent level throughout the last few years. In their majority, documents came out of the United States, although more recently, Chinese institutions are those displaying the largest production. Keywords analysis indicated that one-third of the publications concerned synthesis, around 20% explored self-assembly and morphological aspects, and another 20% referred to block copolymer applications in solution. In particular, 2019 confirmed the expansion of studies related to drug delivery, and in minor extent, to a deeper view of self-assembling. Styrene-butadiene-styrene block copolymer was the most popular in studies covering both basic and industrially oriented aspects. Other highly investigated copolymers are PEO-<i>b</i>-PPO-<i>b</i>-PEO (Pluronic©) and amphiphilic block copolymers based on polycaprolactone or poly(lactic acid), which owed their success to their potential as delivery vehicles. Future trending topics will concern nanomedicine challenges and technology-related applications, with a special attention toward the orientation and ordering of mesophase-separated morphologies. Copolymer ; Block (permutation group theory) ; Materials science ; Computer science ; Polymer science ; Polymer ; Mathematics ; Composite material ; Combinatorics Block Copolymer Self-Assembly ; Advanced Battery Materials and Technologies ; Polymer Nanocomposites and Properties
Authors: Furui Zhang | Xiaobing Hu | Eric W. Roth | Yonghwi Kim | SonBinh T. Nguyen
Source: Chemistry of Materials (article, 2020-04-23)
Field: Chemistry — Inorganic Chemistry

Template-Assisted, Seed-Mediated Synthesis of Hierarchically Mesoporous Core–Shell UiO-66: Enhancing Adsorption Capacity and Catalytic Activity through Iterative Growth A hierarchically mesoporous (HM) UiO-66-F4 shell with ∼8 nm mesopores can be iteratively grown on top of UiO-66 nanoparticle (NP) seeds over several cycles templated by Pluronic F-127 micelles. Presumably, the Pluronic micelles that were formed in water can surround UiO-66 NPs to facilitate the overgrowth of an HM-UiO-66-F4 shell in the presence of ZrIV precursors and BDC-F4 linkers. The UiO-66 NP seeds play an important role in directing the continuous growth of the HM-UiO-66-F4 shell, as only a nonporous phase was obtained in their absence. This template-assisted, seed-mediated method can be extended to produce other UiO-66-X (X = (OH)2, (COOH)2, etc.) shells, demonstrating its generality for the UiO-66 family of metal–organic frameworks. Notably, the incorporation of mesopores into the thrice-overgrown UiO-66@HM|3rd-UiO-66-F4 materials leads to impressive enhancements in the per-mass uptake capacity of Direct Blue 86, a large anionic dye: 320% better than the parent UiO-66 seeds and 150% better than that for a [UiO-66 + UiO-66-F4] physical mixture at the same mass proportion. Similar enhancements were also observed in the catalyzed oxidation of thioanisole. Mesoporous material ; Catalysis ; Materials science ; Micelle ; Chemical engineering ; Adsorption ; Nanoparticle ; Shell (structure) ; Porosity ; Nanotechnology ; Chemistry ; Organic chemistry ; Aqueous solution ; Composite material Metal-Organic Frameworks: Synthesis and Applications ; Covalent Organic Framework Applications ; Zeolite Catalysis and Synthesis
Authors: Geh Wilson Ejuh | Fridolin Tchangnwa Nya | Noël Djongyang | J.M.B. Ndjaka
Source: SN Applied Sciences (article, 2020-06-19)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Theoretical study on the electronic, optoelectronic, linear and non linear optical properties and UV–Vis Spectrum of Coronene and Coronene substituted with Chlorine Coronene ; Hyperpolarizability ; Density functional theory ; Molecule ; Chemistry ; Chlorine ; Photonics ; Materials science ; Optoelectronics ; Computational chemistry Nonlinear Optical Materials Research ; Organic Chemistry Cycloaddition Reactions ; Organic Electronics and Photovoltaics
Authors: Luca Bellucci | Valentina Tozzini
Source: Molecules (review, 2020-01-14)
Field: Materials Science — Materials Chemistry

Engineering 3D Graphene-Based Materials: State of the Art and Perspectives Graphene is the prototype of two-dimensional (2D) materials, whose main feature is the extremely large surface-to-mass ratio. This property is interesting for a series of applications that involve interactions between particles and surfaces, such as, for instance, gas, fluid or charge storage, catalysis, and filtering. However, for most of these, a volumetric extension is needed, while preserving the large exposed surface. This proved to be rather a hard task, especially when specific structural features are also required (e.g., porosity or density given). Here we review the recent experimental realizations and theoretical/simulation studies of 3D materials based on graphene. Two main synthesis routes area available, both of which currently use (reduced) graphene oxide flakes as precursors. The first involves mixing and interlacing the flakes through various treatments (suspension, dehydration, reduction, activation, and others), leading to disordered nanoporous materials whose structure can be characterized <i>a posteriori</i>, but is difficult to control. With the aim of achieving a better control, a second path involves the functionalization of the flakes with pillars molecules, bringing a new class of materials with structure partially controlled by the size, shape, and chemical-physical properties of the pillars. We finally outline the first steps on a possible third road, which involves the construction of pillared multi-layers using epitaxial regularly nano-patterned graphene as precursor. While presenting a number of further difficulties, in principle this strategy would allow a complete control on the structural characteristics of the final 3D architecture. Graphene ; Nanoporous ; Oxide ; Materials science ; Nanotechnology ; Porosity ; Interlacing ; Computer science ; Composite material Graphene research and applications ; Supercapacitor Materials and Fabrication ; Graphene and Nanomaterials Applications
Authors: Ruth Prieto‐Montero | Alberto Katsumiti | Miren P. Cajaraville | Íñigo López‐Arbeloa | Virginia Martínez‐Martínez
Source: Sensors (article, 2020-09-29)
Field: Materials Science — Biomaterials

Functionalized Fluorescent Silica Nanoparticles for Bioimaging of Cancer Cells Functionalized fluorescent silica nanoparticles were designed and synthesized to selectively target cancer cells for bioimaging analysis. The synthesis method and characterization of functionalized fluorescent silica nanoparticles (50-60 nm), as well as internalization and subcellular localization in HeLa cells is reported here. The dye, rhodamine 101 (R101) was physically embedded during the sol-gel synthesis. The dye loading was optimized by varying the synthesis conditions (temperature and dye concentration added to the gel) and by the use of different organotriethoxysilanes as a second silica precursor. Additionally, R101, was also covalently bound to the functionalized external surface of the silica nanoparticles. The quantum yields of the dye-doped silica nanoparticles range from 0.25 to 0.50 and demonstrated an enhanced brightness of 230-260 fold respect to the free dye in solution. The shell of the nanoparticles was further decorated with PEG of 2000 Da and folic acid (FA) to ensure good stability in water and to enhance selectivity to cancer cells, respectively. In vitro assays with HeLa cells showed that fluorescent nanoparticles were internalized by cells accumulating exclusively into lysosomes. Quantitative analysis showed a significantly higher accumulation of FA functionalized fluorescent silica nanoparticles compared to nanoparticles without FA, proving that the former may represent good candidates for targeting cancer cells. HeLa ; Fluorescence ; Nanoparticle ; Cancer cell ; Rhodamine ; Silicon dioxide ; Chemistry ; Materials science ; Rhodamine B ; Surface modification ; Nanotechnology ; Biophysics ; In vitro ; Organic chemistry ; Cancer ; Biochemistry ; Catalysis Nanoparticle-Based Drug Delivery ; Nanoplatforms for cancer theranostics ; Advanced biosensing and bioanalysis techniques
Authors: Maxime Boniface | Milivoj Plodinec | Robert Schlögl | Thomas Lunkenbein
Source: Topics in Catalysis (article, 2020-11-01)
Field: Materials Science — Materials Chemistry

Quo Vadis Micro-Electro-Mechanical Systems for the Study of Heterogeneous Catalysts Inside the Electron Microscope? Abstract During the last decade, modern micro-electro-mechanical systems (MEMS) technology has been used to create cells that can act as catalytic nanoreactors and fit into the sample holders of transmission electron microscopes. These nanoreactors can maintain atmospheric or higher pressures inside the cells as they seal gases or liquids from the vacuum of the TEM column and can reach temperatures exceeding 1000 °C. This has led to a paradigm shift in electron microscopy, which facilitates the local characterization of structural and morphological changes of solid catalysts under working conditions. In this review, we outline the development of state-of-the-art nanoreactor setups that are commercially available and are currently applied to study catalytic reactions in situ or operando in gaseous or liquid environments. We also discuss challenges that are associated with the use of environmental cells. In catalysis studies, one of the major challenge is the interpretation of the results while considering the discrepancies in kinetics between MEMS based gas cells and fixed bed reactors, the interactions of the electron beam with the sample, as well as support effects. Finally, we critically analyze the general role of MEMS based nanoreactors in electron microscopy and catalysis communities and present possible future directions. Nanoreactor ; Nanotechnology ; Microelectromechanical systems ; Catalysis ; Microreactor ; Materials science ; Characterization (materials science) ; Transmission electron microscopy ; Electron microscope ; Chemical engineering ; Chemistry ; Nanoparticle ; Optics ; Organic chemistry ; Physics Electronic and Structural Properties of Oxides ; Electrochemical Analysis and Applications ; Electrocatalysts for Energy Conversion
Authors: Gabriele Barrera | Marco Coïsson | Federica Celegato | Luca Martino | Priyanka Tiwari | Roshni Verma | S. N. Kane | F. Mazaleyrat | Paola Tiberto
Source: Sensors (article, 2020-04-10)
Field: Materials Science — Materials Chemistry

Specific Loss Power of Co/Li/Zn-Mixed Ferrite Powders for Magnetic Hyperthermia An important research effort on the design of the magnetic particles is increasingly required to optimize the heat generation in biomedical applications, such as magnetic hyperthermia and heat-assisted drug release, considering the severe restrictions for the human body's exposure to an alternating magnetic field. Magnetic nanoparticles, considered in a broad sense as passive sensors, show the ability to detect an alternating magnetic field and to transduce it into a localized increase of temperature. In this context, the high biocompatibility, easy synthesis procedure and easily tunable magnetic properties of ferrite powders make them ideal candidates. In particular, the tailoring of their chemical composition and cation distribution allows the control of their magnetic properties, tuning them towards the strict demands of these heat-assisted biomedical applications. In this work, Co<sub>0.76</sub>Zn<sub>0.24</sub>Fe<sub>2</sub>O<sub>4,</sub> Li<sub>0.375</sub>Zn<sub>0.25</sub>Fe<sub>2.375</sub>O<sub>4</sub> and ZnFe<sub>2</sub>O<sub>4</sub> mixed-structure ferrite powders were synthesized in a 'dry gel' form by a sol-gel auto-combustion method. Their microstructural properties and cation distribution were obtained by X-ray diffraction characterization. Static and dynamic magnetic measurements were performed revealing the connection between the cation distribution and magnetic behavior. Particular attention was focused on the effect of Co<sup>2+</sup> and Li<sup>+</sup> ions on the magnetic properties at a magnetic field amplitude and the frequency values according to the practical demands of heat-assisted biomedical applications. In this context, the specific loss power (SLP) values were evaluated by ac-hysteresis losses and thermometric measurements at selected values of the dynamic magnetic fields. Materials science ; Magnetic hyperthermia ; Magnetic nanoparticles ; Magnetic field ; Ferrite (magnet) ; Heat generation ; Magnetism ; Magnetic hysteresis ; Context (archaeology) ; Nuclear magnetic resonance ; Nanotechnology ; Nanoparticle ; Chemical engineering ; Magnetization ; Condensed matter physics ; Composite material ; Thermodynamics ; Physics Magnetic Properties and Synthesis of Ferrites ; Iron oxide chemistry and applications ; Characterization and Applications of Magnetic Nanoparticles
Authors: Christina Zovko | Sebastian Bestgen | Christoph Schoo | Anne Görner | José M. Goicoechea | Peter W. Roesky
Source: Chemistry - A European Journal (article, 2020-04-14)
Field: Chemistry — Organic Chemistry

A Phosphine Functionalized β‐Diketimine Ligand for the Synthesis of Manifold Metal Complexes A bis(diphenyl)-phosphine functionalized β-diketimine (PNac-H) was synthesized as a flexible ligand for transition metal complexes. The newly designed ligand features symmetrically placed phosphine moieties around a β-diketimine unit, forming a PNNP-type pocket. Due to the hard and soft donor atoms (N vs. P) the ligand can stabilize various coordination polyhedra. A complete series ranging from coordination numbers 2 to 6 was realized. Linear, trigonal planar, square planar, tetrahedral, square pyramidal, and octahedral coordination arrangements containing the PNac-ligand around the metal center were observed by using suitable metal sources. Hereby, PNac-H or its anion PNac<sup>-</sup> acts as mono-, bi- and tetradendate ligand. Such a broad flexibility is unusual for a rigid tetradentate system. The structural motifs were realized by treatment of PNac-H with a series of late transition metal precursors, for example, silver, gold, nickel, copper, platinum, and rhodium. The new complexes have been fully characterized by single crystal X-ray diffraction, NMR, IR, UV/Vis spectroscopy, mass spectrometry as well as elemental analysis. Additionally, selected complexes were investigated regarding their photophysical properties. Thus, PNac-H proved to be an ideal ligand platform for the selective coordination and stabilization of various metal ions in diverse polyhedra and oxidation states. Ligand (biochemistry) ; Crystallography ; Chemistry ; Phosphine ; Transition metal ; Octahedron ; Square pyramidal molecular geometry ; Rhodium ; Denticity ; Metal ; Single crystal ; Crystal structure ; Organic chemistry Organometallic Complex Synthesis and Catalysis ; Carbon dioxide utilization in catalysis ; Polyoxometalates: Synthesis and Applications