jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: P. Sivaprakash | Raja Venkatesan | S. Esakki Muthu | Mohammad Rafe Hatshan | Alexandre A. Vetcher | Seong‐Cheol Kim | Ikhyun Kim
Source: Heliyon (article, 2023-12-01)
Field: Materials Science — Materials Chemistry

RETRACTED: Effect of different etching times on the structural, morphological, electrical, and antimicrobial properties of mesoporous silicon The present work focuses on the structural, morphological, electrical characteristics, and antibacterial activity of mesoporous silicon (PS) against <i>S. aureus</i> and <i>E. coli</i>. We depict the structural and antimicrobial activity of PS as a result of different etching times (10.0, 20.0, 30.0, 40.0, 50.0, and 60.0 min) with a current density of 100 mA/cm<sup>2</sup>. The structural and morphological characteristics of synthesized PS have been examined with Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). FTIR spectra have been used to confirmed the Si-O, Si-<i>O</i>-Si bond and the adsorption on the surface of PS nanoparticles. The formation of pores on the c-Si wafer results in an analysis of a photoluminescence (PL) band at 712 nm, which changes with etching time in a process similar to current density. The correlation exist among etching times and the ideality factor (η) and barrier height (ф<sub>b</sub>). Gram-positive (<i>S. aureus</i>) and Gram-negative (<i>E. coli</i>) bacteria showed enhanced antimicrobial activity against the PS nanoparticles. The synthesized of PS has been shown with good electrical and antimicrobial activities. Materials science ; Etching (microfabrication) ; Silicon ; Antimicrobial ; Mesoporous material ; Nanotechnology ; Chemical engineering ; Chemistry ; Engineering ; Optoelectronics ; Organic chemistry Silicon Nanostructures and Photoluminescence ; Nanoparticles: synthesis and applications ; Nanowire Synthesis and Applications
Authors: Xiaobin Xie | Marijn A. van Huis | Alfons van Blaaderen
Source: The Journal of Physical Chemistry C (article, 2023-08-03)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Morphology-Controlled Growth of Crystalline Ag–Pt-Alloyed Shells onto Au Nanotriangles and Their Plasmonic Properties The surface plasmon resonance of noble-metal nanoparticles depends on nanoscale size, morphology, and composition, and provides great opportunities for applications in biomedicine, optoelectronics, (photo)catalysis, photovoltaics, and sensing. Here, we present the results of synthesizing ternary metallic or trimetallic nanoparticles, Au nanotriangles (Au NTs) with crystalline Ag-Pt alloyed shells, the morphology of which can be adjusted from a yolk-shell to a core-shell structure by changing the concentration of AgNO<sub>3</sub> or the concentration of Au NT seeds, while the shell thickness can be precisely controlled by adjusting the concentration of K<sub>2</sub>PtCl<sub>4</sub>. By monitoring the growth process with UV-vis spectra and scanning transmission electron microscopy (STEM), the shells on the Au NT-Ag-Pt yolk-shell nanoparticles were found to grow via a galvanic replacement synergistic route. The plasmonic properties of the as-synthesized nanoparticles were investigated by optical absorbance measurements. Materials science ; Nanoparticle ; Plasmon ; Noble metal ; Nanomaterial-based catalyst ; Surface plasmon resonance ; Nanotechnology ; Ternary operation ; Nanoshell ; Metal ; Chemical engineering ; Galvanic cell ; Nucleation ; Shell (structure) ; Absorbance ; Optoelectronics ; Chemistry ; Metallurgy ; Composite material Gold and Silver Nanoparticles Synthesis and Applications ; Copper-based nanomaterials and applications ; Plasmonic and Surface Plasmon Research
Authors: María Elena Sánchez Vergara | Luis Alberto Cantera Cantera | Citlalli Ríos | Roberto Salcedo
Source: Preprints.org (preprint, 2023-07-13)
Field: Materials Science — Polymers and Plastics

Preparation of Hybrid Films Based in Aluminum 8-hydroxyquinoline for Application in Organic Light-emitting Devices In the present work we have investigated an organic semiconductor based on tris(8-hydroxyquinoline) aluminum (AlQ3) doped with tetracyanoquinodimethane (TCNQ), which can be used as a photoactive layer in organic light-emitting device (OLED). DFT calculations were carried out to optimize the structure of semiconductor species and get related constants in order to compare experimental and theoretical results. The semiconductor AlQ3-TCNQ was structurally characterized and their experimental IR spectrum was compared with that obtained through DFT calculations. Subsequently, AlQ3-TCNQ films with polypyrrole (PPy) matrix were fabricated, they were morphologically and mechanically characterized by Scanning Electron and Atomic Force Microscopy techniques. The maximum stress for the film is 8.66 MPa and the Knoop hardness is 0.0311. The film was analyzed in its optical behavior and the optical properties of hybrid film were found to exhibit two indirect allowed transitions at 2.64 and 3.44 eV. Finally, an OLED type was fabricated that was electrically characterized. Applying a cubic-spline approximation to fit cubic polynomials to the J-V curves, the ohmic to SCLC transition voltage VON and the trap-filled-limit voltage VTFL for the device were obtained. Then, the free carrier density and trap density for the device were approximated to n0=2.4787×10171m3 and Nt=1.7419×10291m3 respectively. Materials science ; OLED ; Ohmic contact ; Semiconductor ; Optoelectronics ; Organic semiconductor ; Aluminium ; Density functional theory ; Analytical Chemistry (journal) ; Layer (electronics) ; Computational chemistry ; Nanotechnology ; Chemistry ; Composite material ; Organic chemistry Conducting polymers and applications ; Organic Electronics and Photovoltaics ; Organic Light-Emitting Diodes Research
Authors: Nicolas Richy | Safa Gam | Sabri Messaoudi | Amédée Triadon | Olivier Mongin | Mireille Blanchard‐Desce | Camille Latouche | Mark G. Humphrey | Abdou Boucekkine | Jean‐François Halet | Frédéric Paul
Source: Photochem (article, 2023-02-20)
Field: Materials Science — Materials Chemistry

Linear and Nonlinear Optical Properties of Quadrupolar Bithiophenes and Cyclopentadithiophenes as Fluorescent Oxygen Photosensitizers The linear and nonlinear optical properties of two quadrupolar bithiophenes and two quadrupolar cyclopentadithiophenes have been investigated. At the 5,5′ positions of the central bi/dithiophene units, the molecules possess 1,4-phenylalkynyl groups that bear either electron-donating (NPh2) or electron-withdrawing (SO2CF3) groups. The optical properties were experimentally studied and modelled via quantum chemistry computations of key configurations and conformations. All the compounds show good light harvesting efficiency due to their strong absorption in the visible range. These fluorescent compounds are also good two-photon absorbers in the NIR range that can photosensitize oxygen in toluene. DFT calculations reveal that the mixtures of conformers in a solution show similar linear optical properties. TD-DFT calculations reproduce the experimental spectroscopic data fairly well, including vibronic couplings in the fluorescence spectra. The lowest excited state for two-photon absorption corresponds to the S2 state. The roles of the SO2CF3 and NPh2 terminal groups on the nonlinear response were analyzed for possible bio-oriented applications, with the cyclopentadithiophenes showing the most promising figures of merit. Fluorescence ; Excited state ; Absorption (acoustics) ; Photochemistry ; Molecule ; Singlet oxygen ; Molecular physics ; Conformational isomerism ; Toluene ; Electron ; Two-photon absorption ; Absorption spectroscopy ; Chemistry ; Materials science ; Oxygen ; Atomic physics ; Optics ; Physics ; Laser ; Organic chemistry ; Quantum mechanics Porphyrin and Phthalocyanine Chemistry ; Nonlinear Optical Materials Research ; Nonlinear Optical Materials Studies
Authors: Rihards Klūga | Artis Kinēns | Edgars Sūna
Source: Chemistry - A European Journal (article, 2023-10-02)
Field: Chemistry — Organic Chemistry

Chiral 4‐MeO‐Pyridine (MOPY) Catalyst for Enantioselective Cyclopropanation: Attenuation of Lewis Basicity Leads to Improved Catalytic Efficiency The design of pyridine-derived organocatalysts aims at the increase of their Lewis basicity, however such an approach is not always efficient. For example, strongly Lewis basic DMAP is completely inefficient as catalyst in the cyclopropanation reaction. Herein we disclose an alternative approach that relies on attenuation of DMAP Lewis basicity. Specifically, the replacement of 4-dimethylamino substituent in DMAP for 4-MeO group delivered a highly efficient catalyst for cyclopropanation of electron-deficient olefins with α-bromoketones. Kinetic studies provide compelling evidence that the superior catalytic efficiency of 4-MeO pyridine (MOPY) is to be attributed to the favorable balance between Lewis basicity and leaving group ability. The use of chiral, enantiomerically pure MOPY catalyst has helped to achieve high enantioselectivities (up to 91 : 9 er) in the previously unreported pyridine-catalyzed cyclopropanation reaction. Cyclopropanation ; Pyridine ; Catalysis ; Lewis acids and bases ; Substituent ; Chemistry ; Enantioselective synthesis ; Medicinal chemistry ; Organic chemistry Cyclopropane Reaction Mechanisms ; Asymmetric Hydrogenation and Catalysis ; Synthetic Organic Chemistry Methods
Authors: Cheng‐Hui Shen | Chung‐Wei Kung
Source: ChemElectroChem (article, 2023-10-23)
Field: Chemistry — Inorganic Chemistry

Stable and Electrochemically “Inactive” Metal−Organic Frameworks for Electrocatalysis Abstract Metal−organic frameworks (MOFs) with ultrahigh surface areas and interconnected porosity have been considered as attractive materials for electrocatalysis. Numerous research efforts have thus been made to develop the “electrocatalytic MOFs”. But the poor stability in water and the low electrical conductivity of most MOFs strongly limit the direct use of such electrochemically active MOFs. In this article, we aim to highlight a different concept – utilizing stable but electrochemically “inactive” MOFs for electrocatalytic reactions. Though the porous framework does not exhibit electrocatalytic activity and is electrically insulating, it could modulate the microenvironment near the underlying surface of the electrocatalyst and thus adjust the reaction rates and selectivity of the complicated electrochemical reactions. Herein, such strategies reported previously are reviewed, and the potential opportunities in future studies are discussed. Electrocatalyst ; Metal-organic framework ; Porosity ; Materials science ; Electrochemistry ; Nanotechnology ; Metal ; Chemical engineering ; Chemistry ; Electrode ; Composite material ; Physical chemistry ; Metallurgy ; Adsorption Metal-Organic Frameworks: Synthesis and Applications ; Advanced Photocatalysis Techniques ; Covalent Organic Framework Applications
Authors: Sophie Jancke | Chen Liu | Ruosong Wang | Swagato Sarkar | Quinn A. Besford | Tobias A. F. König | Jürgen Popp | Dana Cialla‐May | Christian Roßner
Source: Nanoscale (article, 2023-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Turning on hotspots: supracolloidal SERS probes made brilliant by an external activation mechanism We achieved external activation of local hot-spot sites in supracolloidal assembly structures. The concept was demonstrated by boosting surface-enhanced Raman scattering (SERS) efficiency by one order of magnitude through a heating-induced process. Our approach involves assembling gold nanoparticles with distinct dimensions, <i>i.e.</i> 16 and 80 nm, into well-defined planet-satellite-type arrangement structures using thermoresponsive (poly(<i>N</i>-isopropylacrylamide)) star polymer linkers. Insights into the assembly process were obtained by calculations within the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory framework. We observe one order of magnitude increase in SERS enhancement by a heating-induced volume-phase transition. This magnification aligns with simulations run using the finite-difference time-domain (FDTD) method. The implications of this adaptive supracolloidal concept are twofold: Firstly, our approach bypasses limitations of existing systems that are associated with the limited accessibility of electromagnetic hot-spot sites in strongly coupled, static assemblies of plasmonic nanoparticles, by providing the capability of dynamic hot-spot re-configuration. Second, these externally activated probes offer promising opportunities for the development of messenger materials and associated sensing strategies. Mechanism (biology) ; Nanotechnology ; Materials science ; Physics Gold and Silver Nanoparticles Synthesis and Applications ; Quantum Dots Synthesis And Properties ; Polymer Surface Interaction Studies
Authors: Franziska Spruner von Mertz | Alexander Villinger | Peter Ehlers | Peter Langer
Source: European Journal of Organic Chemistry (article, 2023-11-28)
Field: Chemistry — Organic Chemistry

Synthesis and Properties of Pyridofluoranthenes Abstract A series of N‐doped Benzo[b]fluoranthenes was synthesized. Specifically varying the position of the Nitrogen atom in all four positions of the bottom ring. In the last reaction step the five‐membered ring of the unsubstituted core structure is formed by palladium catalyzed CH‐activation. This synthetic approach allows for the selective introduction of heteroatoms into the core structure and leads to four regioisomeric products. Subsequently the optical and electrochemical properties of these polyaromatic heterocycles were compared. DFT/TD‐DFT and NICS calculations were performed to further analyze, how the position of Nitrogen impacts the overall characteristics of the molecules. This composes a thorough study on the chemical behavior of N‐doped Benzo[b]fluoranthenes. Heteroatom ; Chemistry ; Ring (chemistry) ; Nitrogen atom ; Molecule ; Palladium ; Electrochemistry ; Stereochemistry ; Nitrogen ; Computational chemistry ; Combinatorial chemistry ; Catalysis ; Organic chemistry ; Physical chemistry Synthesis and Properties of Aromatic Compounds ; Catalytic C–H Functionalization Methods ; Axial and Atropisomeric Chirality Synthesis
Authors: Efstathia Triantafyllopoulou | Dimitriοs Selianitis | Νatassa Pippa | Maria Gazouli | Georgia Valsami | Stergios Pispas
Source: Polymers (article, 2023-04-22)
Field: Chemistry — Organic Chemistry

Development of Hybrid DSPC:DOPC:P(OEGMA950-DIPAEMA) Nanostructures: The Random Architecture of Polymeric Guest as a Key Design Parameter Hybrid nanoparticles have gained a lot of attention due to their advantageous properties and versatility in pharmaceutical applications. In this perspective, the formation of novel systems and the exploration of their characteristics not only from a physicochemical but also from a biophysical perspective could promote the development of new nanoplatforms with well-defined features. In the current work, lipid/copolymer bilayers were formed in different lipid to copolymer ratios and examined via differential scanning calorimetry as a preformulation study to decipher the interactions between the biomaterials, followed by nanostructure preparation by the thin-film hydration method. Physicochemical and toxicological evaluations were conducted utilizing light scattering techniques, fluorescence spectroscopy, and MTS assay. 1,2-dioctadecanoyl-sn-glycero-3-phosphocholine (DSPC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) in different weight ratios were the chosen lipids, while a linear random copolymer with pH- and thermoresponsive properties comprised of oligo (ethylene glycol) methyl ether methacrylate (OEGMA) and 2-(diisopropylamino) ethyl methacrylate (DIPAEMA) in different ratios was used. According to our results, non-toxic hybrid nanosystems with stimuli-responsive properties were successfully formulated, and the main parameters influencing their overall performance were the hydrophilic/hydrophobic balance, lipid to polymer ratio, and more importantly the random copolymer topology. Hopefully, this investigation can promote a better understanding of the factors affecting the behavior of hybrid systems. Copolymer ; Methacrylate ; Materials science ; Ethylene glycol ; Differential scanning calorimetry ; Polymer ; Dynamic light scattering ; Nanostructure ; Chemical engineering ; Nanoparticle ; Nanotechnology ; Polymer chemistry ; Chemistry ; Organic chemistry Advanced Polymer Synthesis and Characterization ; Lipid Membrane Structure and Behavior ; Nanoparticle-Based Drug Delivery
Authors: R. A. Bakar | Kyle S. Hepburn | Joseph L. Keddie | Peter J. Roth
Source: Angewandte Chemie (article, 2023-06-28)
Field: Chemistry — Organic Chemistry

Degradable, Ultraviolet‐Crosslinked Pressure‐Sensitive Adhesives Made from Thioester‐Functional Acrylate Copolymers Abstract Pressure‐sensitive adhesives (PSAs) are made from soft, irreversibly lightly crosslinked polymers. Even after removal from surfaces, they retain insoluble networks which pose problems during the recycling of glass and cardboard. Herein, degradable PSAs are presented that provide the required performance in use but have networks that can be degraded after use. A series of copolymers was prepared through radical copolymerization of n ‐butyl acrylate, 4‐acryloyloxy benzophenone (ABP) photo‐crosslinker, and dibenzo[c,e]oxepin‐5(7H)‐thione (DOT) to provide degradable backbone thioesters. The optimum tack and peel strengths were found for molar contents of 0.05 mol% ABP and 0.25 mol% DOT. Degradation of the backbone thioesters through aminolysis or thiolysis led to the full dissolution of the networks, loss of adhesive properties of films (decreases in the measured tack and peel strengths), and the quick detachment of model labels from a substrate. Inclusion of DOT into PSAs offers a viable route toward degradable and recyclable packaging labels. Copolymer ; Adhesive ; Acrylate ; Polymer chemistry ; Aminolysis ; Polymer ; Benzophenone ; Materials science ; Pressure sensitive ; Chemical engineering ; Chemistry ; Organic chemistry ; Composite material Advanced Polymer Synthesis and Characterization ; biodegradable polymer synthesis and properties ; Silicone and Siloxane Chemistry
Authors: Monika Kušter | Janez Kovač | Zoran Samardžija | Matej Komelj | Sorour Semsari Parapari | Matejka Podlogar | Jean‐Marie Dubois | Sašo Šturm
Source: Preprints.org (preprint, 2023-04-19)
Field: Materials Science — Materials Chemistry

Impact Of Tuned Oxidation on the Surface Energy of Sintered Samples Produced from Atomised B-Doped Al-Cu-Fe Quasicrystalline Powders Super-hydrophobic surfaces and coatings have stimulated a great deal of research, with the aim to achieve better wetting properties. Factors such as surface chemistry and roughness play an important role in changing the surface energy, which in turn leads to changes in the wettability. Here, we have analysed the time dependence of the oxide layer and possible surface adsorbates on the surface topography of an Al59Cu25Fe13B3 quasicrystalline material for changes to the wettability. The quasicrystalline matrix phase was 94 % of the sample volume, and covered by a very smooth, amorphous oxide layer. The AlB12 and AlFe2B2 boron-rich phases were embedded in the quasicrystalline material as a result of a 3 at.% boron addition, which makes atomisation of the material a simpler process. Under ambient conditions the sample was naturally covered by an oxide layer; therefore, it is referred to as “surfenergy”, to distinguish it from the conventional surface energy of a bare quasicrystal surface. The growth of the oxide layer with atmospheric ageing and annealing at 500° C in air for various times was investigated for both cases. The phase most prone to oxidation was the boron-rich AlFe2B2, which influenced the topography of the surface and accordingly the wetting behaviour of the specimen. We demonstrated that the surfenergy depends on the polar component, which is the most sensitive to the operating conditions. A correlation between the surfenergy components and the surface roughness was found. In addition, theoretical models to determine the wettability were included. Wetting ; Materials science ; Oxide ; Annealing (glass) ; Surface energy ; Surface roughness ; Quasicrystal ; Surface finish ; Contact angle ; Boron ; Amorphous solid ; Coating ; Chemical engineering ; Layer (electronics) ; Wetting layer ; Composite material ; Metallurgy ; Analytical Chemistry (journal) ; Crystallography ; Chemistry ; Organic chemistry Quasicrystal Structures and Properties ; nanoparticles nucleation surface interactions ; Laser-Ablation Synthesis of Nanoparticles
Authors: Zixin Wang | Hui Wang
Source: Nanoscale Advances (article, 2023-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Au@C/Pt core@shell/satellite supra-nanostructures: plasmonic antenna–reactor hybrid nanocatalysts Integration of plasmonic nanoantennas with catalytically active reactors in deliberately designed hybrid supra-nanostructures creates a dual-functional materials platform, based upon which precise modulation of catalytic reaction kinetics becomes accomplishable through optical excitations of plasmon resonances. Here, we have developed a multistep synthetic approach that enables us to assemble colloidal Au@C/Pt core@shell/satellite supra-nanostructures, in which the Au core functions as a light-harvesting plasmonic nanoantenna, the Pt satellites act as catalytically active reactors, and the C shell serves as a nanoscale dielectric spacer separating the reactors from the antenna, respectively. By adjusting several synthetic parameters, the size of the Au core, the thickness of the C shell, and the surface coverage of Pt satellites can all be tuned independently. Choosing Pt-catalyzed cascade oxidation of 3,3',5,5'-tetramethylbenzidine in an aerobic aqueous environment as a model reaction, we have systematically studied the detailed kinetic features of the catalytic reactions both in the dark and under visible light illumination over a broad range of reaction conditions, which sheds light on the interplay between plasmonic and catalytic effects in these antenna-reactor nanohybrids. The plasmonic antenna effect can be effectively harnessed to kinetically modulate multiple crucial steps during the cascade reactions, benefiting from plasmon-enhanced interband electronic transitions in the Pt satellites and plasmon-enhanced intramolecular electronic excitations in chromogenic intermediate species. In addition to the plasmonic antenna effect, photothermal transduction derived from plasmonic excitations can also provide significant contributions to the kinetic enhancements under visible light illumination. The knowledge gained from this work serves as important guiding principles for rational design and structural optimization of plasmonic antenna-reactor hybrid nanomaterials, endowing us with enhanced capabilities to kinetically modulate targeted catalytic/photocatalytic molecule-transforming processes through light illumination. Nanomaterial-based catalyst ; Plasmon ; Shell (structure) ; Core (optical fiber) ; Satellite ; Antenna (radio) ; Materials science ; Optoelectronics ; Nanotechnology ; Nanoparticle ; Aerospace engineering ; Telecommunications ; Computer science ; Engineering ; Composite material Gold and Silver Nanoparticles Synthesis and Applications ; Nanocluster Synthesis and Applications ; Advanced Nanomaterials in Catalysis
Authors: Yating Wen | Weiqing Xu | Liuyong Hu | Miao Xu | Wenling Gu | Hongcheng Sun | Chengzhou Zhu
Source: Sensors & Diagnostics (article, 2023-01-01)
Field: Materials Science — Materials Chemistry

Tuning atomic-scale sites in metal–organic framework-based nanozymes for sensitive biosensing This review provides an overview of the methods for tuning atomic-scale sites in metal–organic framework-based nanozymes for sensitive biosensing. Biosensor ; Nanotechnology ; Scale (ratio) ; Metal-organic framework ; Atomic units ; Chemistry ; Materials science ; Physics ; Physical chemistry Advanced Nanomaterials in Catalysis ; Nanocluster Synthesis and Applications ; Advanced biosensing and bioanalysis techniques