jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Taro Uematsu | Ryunosuke Izumi | Shoki Sugano | R. Sugano | Tatsuya Hirano | Genichi Motomura | Tsukasa Torimoto | Susumu Kuwabata
Source: Faraday Discussions (article, 2023-09-02)
Field: Materials Science — Materials Chemistry

Spectrally narrow band-edge photoluminescence from AgInS<sub>2</sub>-based core/shell quantum dots for electroluminescence applications This study presents a facile synthesis of cadmium-free ternary and quaternary quantum dots (QDs) and their application to light-emitting diode (LED) devices. AgInS<sub>2</sub> ternary QDs, developed as a substitute for cadmium chalcogenide QDs, exhibited spectrally broad photoluminescence due to intrinsic defect levels. Our group has successfully achieved narrow band-edge PL by a coating with gallium sulfide shell. Subsequently, an intrinsic difficulty in the synthesis of multinary compound QDs, which often results in unnecessary byproducts, was surmounted by a new approach involving the nucleation of silver sulfide followed by material conversion to the intended composition (silver indium gallium sulfide). By fine-tuning this reaction and bringing the starting material closer to stoichiometric compositional ratios, atom economy was further improved. These QDs have been tested in LED applications, but the standard device encountered a significant defective emission that would have been eliminated by the gallium sulfide shells. This problem is addressed by introducing gallium oxide as a new electron transport layer. Photoluminescence ; Quantum dot ; Electroluminescence ; Optoelectronics ; Core (optical fiber) ; Materials science ; Enhanced Data Rates for GSM Evolution ; Shell (structure) ; Nanotechnology ; Computer science ; Telecommunications Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films ; ZnO doping and properties
Authors: Adarsh Mathew Abraham | Venkatesan Subramani
Source: Materials Today Proceedings (article, 2023-06-01)
Field: Materials Science — Biomaterials

Effect of Magnesium as Biomaterial in Biodegrdation Magnesium ; Biocompatibility ; Materials science ; Biodegradation ; Degradation (telecommunications) ; Inert gas ; Polymer ; Inert ; Biomaterial ; Corrosion ; Porosity ; Ceramic ; Metallurgy ; Nanotechnology ; Composite material ; Chemistry ; Computer science ; Organic chemistry Magnesium Alloys: Properties and Applications ; Hydrogen Storage and Materials ; Aluminum Alloys Composites Properties
Authors: А. Н. Гусев | Elena Braga | Ekaterina Zamnius | Igor A. Nauhatskiy | Maria A. Kryukova | Mikhail A. Kiskin | Eugeny V. Alexandrov | Andrey V. Sokolov | Wolfgang Linert
Source: Polyhedron (article, 2023-07-26)
Field: Chemistry — Inorganic Chemistry

Zinc(II) complexes of 3,5-bis(4-pyridyl)-1H-1,2,4-triazole: Synthesis, the role of counter-anions in the formation of a type of crystal structure, and luminescence properties Chemistry ; Zinc ; Luminescence ; Crystal structure ; Single crystal ; 1,2,4-Triazole ; Photoluminescence ; Crystallography ; Ion ; Infrared spectroscopy ; Emission spectrum ; Triazole ; Elemental analysis ; Spectroscopy ; Absorption spectroscopy ; Inorganic chemistry ; Spectral line ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Lanthanide and Transition Metal Complexes ; Magnetism in coordination complexes
Authors: Hoang T. Nguyen | Xu Zhang | Jianguo Wen | Xiang Zhang | Pulickel M. Ajayan | Horacio D. Espinosa
Source: Materials Today (article, 2023-11-01)
Field: Materials Science — Materials Chemistry

Engineering the fracture resistance of 2H-transition metal dichalcogenides using vacancies: An in-silico investigation based on HRTEM images High-resolution transmission electron microscopy ; Transition metal ; Materials science ; Fracture (geology) ; In silico ; Nanotechnology ; Chemistry ; Composite material ; Transmission electron microscopy ; Catalysis 2D Materials and Applications ; Machine Learning in Materials Science ; Metal-Organic Frameworks: Synthesis and Applications
Authors: Sajjad Ghojavand | Eddy Dib | Baptiste Riodent | Aymeric Magisson | Valérie Ruaux | Svetlana Mintova
Source: Advanced Sustainable Systems (article, 2023-03-17)
Field: Chemistry — Inorganic Chemistry

Altering the Atomic Order in Nanosized CHA Zeolites by Postsynthetic Silylation Treatment Abstract In this work, a new post‐synthetic hydrothermal approach leading to simultaneous dealumination and silylation of zeolite nanocrystals is presented. Starting from a nanosized chabazite (CHA) type zeolite with a Si/Al ratio equal to 2, a set of samples with Si/Al ratios up to 4 are obtained by altering the acidity and concentration of the added silica modifier during the post‐synthesis treatment leading to concurrent dealumination and silylation. The effect of the acidity during the post‐synthetic silylation treatment at different pH of 1.0–8.5 at a constant silicon concentration is investigated. The nanosized CHA samples are characterized in details by Fourier transform infrared spectroscopy and NMR spectroscopy ( 1 H, 29 Si, 27 Al), X‐ray diffraction, and thermogravimetric analyses. The post‐synthesis approach reported here can be applied to other zeolite types for fine‐tuning of their structural features including type and location of T‐atoms, silanol sites, and active sites. Silanol ; Zeolite ; Silylation ; Chabazite ; Thermogravimetric analysis ; Fourier transform infrared spectroscopy ; Chemistry ; Silicon ; Infrared spectroscopy ; Hydrothermal synthesis ; Inorganic chemistry ; Chemical engineering ; Hydrothermal circulation ; Catalysis ; Organic chemistry Zeolite Catalysis and Synthesis ; Mesoporous Materials and Catalysis ; Chemical Synthesis and Characterization
Authors: S.H. Joseph | Bejoy Francis
Source: Journal of Applied Polymer Science (article, 2023-08-18)
Field: Materials Science — Polymers and Plastics

Non‐covalent interactions between ionic liquid and graphene nanoplatelets as a tool to fine tune the properties of styrene butadiene rubber nanocomposites Abstract Achieving a robust interfacial interaction between the filler and polymer matrix is crucial for the production of polymer nanocomposites with superior performance. 1‐butyl‐3‐methyl imidazolium bromide (BMIB) was used to fine‐tune the surface properties of graphene nanoplatelets (GnP) in the preparation of ionic liquid (IL)‐functionalized styrene‐butadiene rubber (SBR) nanocomposites. The combined results of Fourier transformation infrared (FTIR) spectroscopy, Raman spectroscopy, x‐ray diffraction (XRD), x‐ray photoelectron spectroscopy, transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) confirmed multiple non‐covalent interactions between BMIB molecules and GnP in modified graphene (IMG). FTIR and XRD studies confirmed the role of IL as an efficient surface modifier for the uniform dispersion of GnP in the SBR matrix via secondary interactions. And the TEM micrographs revealed an even dispersion of IMG in the SBR matrix. TGA and DTG studies showed significant improvements in the thermal stability of SBR nanocomposites with IMG loading. The Cole‐Cole plot showed imperfect semicircles for all the filled systems, indicating heterogeneity. The novel SBR nanocomposites showed an improvement of 271% in tensile strength with 10‐phr IMG loading Materials science ; Thermogravimetric analysis ; Nanocomposite ; Fourier transform infrared spectroscopy ; Styrene-butadiene ; Graphene ; Natural rubber ; Thermal stability ; Chemical engineering ; Polymer ; Dispersion (optics) ; Polymer nanocomposite ; Composite material ; Styrene ; Copolymer ; Nanotechnology Polymer Nanocomposites and Properties ; Graphene research and applications ; Polymer Nanocomposite Synthesis and Irradiation
Authors: Aum Sagar Panda | Yi-Chien Lee | Thanmayee Shastry | Gkreti-Maria Manesi | Apostolos Avgeropoulos | Rong‐Ming Ho
Source: Macromolecules (article, 2023-01-16)
Field: Materials Science — Materials Chemistry

Controlled Orientation of Silicon-Containing Diblock Copolymer Thin Films by Substrate Functionalization Under Vacuum This work demonstrates a simple approach to control the orientation of the self-assembled nanostructured block copolymer thin films of polystyrene-block-polydimethylsiloxane (PS-b-PDMS) by functionalization of the oxide layer (SiO2) on the Si substrate followed by thermal annealing under low-pressure environmental conditions. The substrate can be functionalized through two-step grafting of hydroxy-terminated polystyrene brush (PS–OH brush) followed by hydroxy-terminated polydimethylsiloxane brush (PDMS–OH brush) onto the wafer substrate. By controlling the grafting ratio of PS–OH and PDMS–OH brushes, the affinities of the PS and PDMS blocks with the substrates can be fine-tuned to provide a neutral substrate in order to form perpendicular cylinders from the bottom after thermal annealing. Owing to the vacuum-driven orientation [i.e., thermal annealing under low-pressure environment conditions (∼10–4 Pa)], the orientation of the cylinders can be controlled at the air/polymer interface. Interestingly, by combining the vacuum-driven approach with substrate functionalization, perpendicular cylinders from the air/polymer interface and substrate/polymer interface can be generated, respectively. Consequently, well-aligned perpendicular cylinders with long-range ordering can be fabricated by the self-alignment process. Materials science ; Polydimethylsiloxane ; Polystyrene ; Surface modification ; Copolymer ; Polymer brush ; Annealing (glass) ; Polymer ; Chemical engineering ; Wafer ; Substrate (aquarium) ; Polymer chemistry ; Composite material ; Nanotechnology ; Polymerization Block Copolymer Self-Assembly ; Anodic Oxide Films and Nanostructures ; Organic Electronics and Photovoltaics
Authors: Bhanwar Kumar Malviya | Eric C. Hansen | Caleb J. Kong | Joseph Imbrogno | Jenson Verghese | Steven M. Guinness | Chase A. Salazar | Jean‐Nicolas Desrosiers | C. Oliver Kappe | David Cantillo
Source: Chemistry - A European Journal (article, 2023-08-23)
Field: Chemistry — Organic Chemistry

Metal‐Free Electrochemical Reduction of Disulfides in an Undivided Cell under Mass Transfer Control Electroorganic synthesis is generally considered to be a green alternative to conventional redox reactions. Electrochemical reductions, however, are less advantageous in terms of sustainability, as sacrificial metal anodes are often employed. Divided cell operation avoids contact of the reduction products with the anode and allows for convenient solvent oxidation, enabling metal free greener electrochemical reductions. However, the ion exchange membranes required for divided cell operation on a commercial scale are not amenable to organic solvents, which hinders their applicability. Herein, we demonstrate that electrochemical reduction of oxidatively sensitive compounds can be carried out in an undivided cell without sacrificial metal anodes by controlling the mass transport to a small surface area electrode. The concept is showcased by an electrochemical method for the reductive cleavage of aryl disulfides. Fine tuning of the electrode surface area and current density has enabled the preparation of a wide variety of thiols without formation of any oxidation side products. This strategy is anticipated to encourage further research on greener, metal free electrochemical reductions. Electrochemistry ; Anode ; Redox ; Electrode ; Metal ; Chemistry ; Electrochemical cell ; Mass transfer ; Nanotechnology ; Combinatorial chemistry ; Chemical engineering ; Materials science ; Inorganic chemistry ; Organic chemistry ; Chromatography Sulfur-Based Synthesis Techniques ; Radical Photochemical Reactions ; Catalytic C–H Functionalization Methods
Authors: Dana Cohen | Lothar Houben | Andrea Gálisová | Yishay Feldman | S. Fox | Inbal Biton | Amnon Bar‐Shir
Source: ACS Applied Nano Materials (article, 2023-06-29)
Field: Materials Science — Materials Chemistry

Cooperative Doping in Ultrasmall BaF<sub>2</sub> Nanocrystals for Multimodal <sup>19</sup>F-MRI and CT Applications Nanostructured metal fluorides (nanofluorides) are an emerging type of inorganic nanocrystals (NCs) with unique physiochemical properties for advanced applications. One recent demonstration used water-dispersed ultrasmall CaF2 nanofluorides as imaging agents that combined the advantages of inorganic NCs with the benefit of background-free 19F-magnetic resonance imaging (19F-MRI). Nevertheless, obtaining small nanofluorides with a face-centered cubic crystal structure, where all fluorides are magnetically equivalent to result in a single 19F NMR signal, is challenging for other types of nanofluorides, preventing their use in 19F-MRI. Here, we show the development of ultrasmall, water-dispersed, barium fluoride (BaF2) NCs for bioimaging applications. By doping BaF2 with two types of lanthanides, diamagnetic-La3+ and paramagnetic-Sm3+, we were able to control the morphology and 19F-MR properties of the final La,Sm:BaF2 (termed LaSamBa) formulation. The fine-tuning of the La3+ content enabled us to obtain monodispersed 4.5 nm NCs, and control over the Sm3+ content provided LaSamBa with very short T1 relaxation properties (ca. 100 ms) needed for enhanced 19F-MRI sensitivity. This type of nanofluorides was examined in two different imaging modalities (i.e., 19F-MRI and CT), benefiting from their single 19F-NMR signal and the high atomic number of barium atoms, respectively. As their 19F chemical shift significantly differs from that of other nanofluorides (e.g., CaF2 and SrF2), LaSamBa expanded the nanofluoride library for future multitarget 19F-MRI studies. Fluorine-19 NMR ; Materials science ; Nanocrystal ; Barium ; Nuclear magnetic resonance ; Paramagnetism ; Doping ; Magnetic resonance imaging ; Relaxometry ; Diamagnetism ; Nanotechnology ; Analytical Chemistry (journal) ; Chemistry ; Nuclear magnetic resonance spectroscopy ; Optoelectronics ; Physics ; Spin echo ; Condensed matter physics ; Magnetic field Luminescence Properties of Advanced Materials ; Lanthanide and Transition Metal Complexes ; Atomic and Subatomic Physics Research
Authors: José M. Veleta | Roy Arrieta | Yanyu Wu | Miguel Á. Baeza Cinco | Karen Castañeda | D. Villagrán
Source: Langmuir (article, 2023-06-02)
Field: Chemistry — Inorganic Chemistry

Enhanced Gas Adsorption on Cu<sub>3</sub>(BTC)<sub>2</sub> Metal–Organic Framework by Post-Synthetic Cation Exchange and Computational Analysis Increased gas adsorption in a series of post-synthetically modified metal-organic frameworks (MOFs) of the type HKUST-1 was achieved by the partial cation exchange process. Manipulation of post-synthetic conditions demonstrates high tunability in the site substitution and gas adsorption properties during the dynamic equilibrium process. In this work, post-synthetic modification of Cu<sub>3</sub>(BTC)<sub>2</sub> is carried on by exposure to TM<sup>2+</sup> solutions (TM = Mn, Fe, Co, Ni) at different time intervals. The crystal structure, composition, and morphology were studied by powder X-ray diffraction, Fourier-transform infrared spectroscopy, inductively coupled plasma optical emission spectroscopy, and scanning electron microscopy. Structural analysis supports the retention of the crystal structure and partial substitution of the Cu metal nodes within the framework. A linear increase in the transmetalation process is observed with Fe and Co with a maximum percentage of 39 and 18%, respectively. Conversely, relatively low cation exchange is observed with Mn having a maximum percentage of 2.40% and Ni with only 2.02%. Gas adsorption measurements and surface area analysis were determined for each species. Interestingly, (Cu/Mn)<sub>3</sub>(BTC)<sub>2</sub> revealed the highest CO<sub>2</sub> adsorption capacity of 5.47 mmol/g, compared to 3.08 mmol/g for Cu<sub>3</sub>(BTC)<sub>2</sub>. The overall increased gas adsorption can be attributed to the formation of defects in the crystal structure during the cation exchange process. These results demonstrate the outstanding potential of post-synthetic ion exchange as a general approach to fine-tuning the physical properties of existing MOF architectures. Adsorption ; Metal-organic framework ; Chemistry ; Ion exchange ; Infrared spectroscopy ; Scanning electron microscope ; Fourier transform infrared spectroscopy ; Metal ; Crystal structure ; Cation-exchange capacity ; Transmetalation ; Analytical Chemistry (journal) ; Inorganic chemistry ; Crystallography ; Chemical engineering ; Physical chemistry ; Ion ; Materials science ; Organic chemistry ; Catalysis Metal-Organic Frameworks: Synthesis and Applications ; Zeolite Catalysis and Synthesis ; Enhanced Oil Recovery Techniques
Authors: Zhiming Zhong | Huilei Quan | Jian Zhang | Feng Peng | Wenkai Zhong | Lei Ying
Source: ACS Applied Electronic Materials (article, 2023-11-09)
Field: Materials Science — Materials Chemistry

Improving the Performance of Quantum Dot Light-Emitting Diodes by the Enrichment of a Fluorinated Component on Top of a Hole Transport Layer The hole transport layers are crucial to the device performance of quantum dot light-emitting diodes (QLEDs) due to the huge hole-injection barrier between the work function of the anode and the valence band of II–VI-type quantum dots (QDs). In this study, we developed a heterogeneous hole transport layer (HTL) consisting of two conjugated polymers with almost identical conjugated backbones and successfully applied it in QLEDs. The introduction of trifluoromethyl groups simultaneously modified surface energy, energy levels, and hole transport mobility, thus altering the heterojunction of HTL/QD and enhancing the device’s performance. Based on an optimized weight ratio of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-4,4′-(N-(4-s-butylphenyl)diphenylamine)] (TFB)/TF-DCF3 = 7:3, the maximum current efficiency of a red QLED significantly improved from 14.1 cd A–1 for the reference device based on TFB as the HTL to 23.1 cd A–1. According to X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry, the blend film with a weight ratio of TFB/TF-DCF3 = 7:3 exhibited a gradient component distribution, with TF-DCF3 enriched on the top surface. Our research sheds light on the advantage of a hole transport layer with a fluorinated component and its application in a QLED and provides an approach to fine-tune the component’s vertical distribution of HTL. Quantum dot ; X-ray photoelectron spectroscopy ; Optoelectronics ; Anode ; Diode ; Materials science ; Heterojunction ; Light-emitting diode ; Work function ; Cathode ; Layer (electronics) ; Chemistry ; Nanotechnology ; Electrode ; Physics ; Physical chemistry ; Nuclear magnetic resonance Quantum Dots Synthesis And Properties ; Semiconductor Quantum Structures and Devices ; Organic Light-Emitting Diodes Research
Authors: Mohamed S. Elafify | Toru Itagaki | Nermeen A. Elkasabgy | Sinar Sayed | Yoshihiro Ito | Motoki Ueda
Source: Biomaterials Science (article, 2023-01-01)
Field: Materials Science — Biomaterials

Reversible transformation of peptide assembly between densified-polysarcosine-driven kinetically and helix-orientation-driven thermodynamically stable morphologies Stimuli-responsive transformable biomaterials development can be manipulated practically by fine-tuning the built-in molecular design of their structural segments. Here, we demonstrate a peptide assembly by the bola-type amphiphilic polypeptide, glycolic acid-polysarcosine (PSar)<sub>13</sub>-<i>b</i>-(L-Leu-Aib)<sub>6</sub>-<i>b</i>-PSar<sub>13</sub>-glycolic acid (S<sub>13</sub>L<sub>12</sub>S<sub>13</sub>), which shows morphological transformations between hydrophilic chain-driven and hydrophobic unit-driven morphologies. The hydrophobic α-helical unit (L-Leu-Aib)<sub>6</sub> precisely controls packing in the hydrophobic layer of the assembly and induces tubule formation. The densified, hydrophilic PSar chain on the assembly surface becomes slightly more hydrophobic as the temperature increases above 70 °C, starting to disturb the helix-helix interaction-driven formation of tubules. As a result, the S<sub>13</sub>L<sub>12</sub>S<sub>13</sub> peptide assembly undergoes a reversible vesicle-nanotube transformation following a time course at room temperature and a heat treatment above 80 °C. Using membrane fluidity analysis with DPH and TMA-DPH and evaluating the environment surrounding the PSar side chain with NMR, we clarify that the vesicle was in a kinetically stable state driven by the dehydrated PSar chain, while the nanotube was in a thermodynamically stable state. Vesicle ; Chemistry ; Amphiphile ; Helix (gastropod) ; Peptide ; Micelle ; Biophysics ; Crystallography ; Self-assembly ; Hydrophobic effect ; Membrane ; Chemical engineering ; Polymer ; Copolymer ; Organic chemistry ; Aqueous solution ; Biochemistry Supramolecular Self-Assembly in Materials ; Lipid Membrane Structure and Behavior ; Polydiacetylene-based materials and applications
Authors: François Mairesse | Lorenzo Maschio | Benoı̂t Champagne
Source: The Journal of Chemical Physics (article, 2023-01-17)
Field: Materials Science — Electronic, Optical and Magnetic Materials

First-principles evaluation of the second harmonic generation response of reference organic and inorganic crystals Using the CRYSTAL17 package at the coupled-perturbed Kohn-Sham (CPKS) level, periodic boundary conditions first-principles calculations are enacted to predict the second harmonic generation second-order nonlinear optical (NLO) susceptibility, χ<sup>(2)</sup>, values of six historical NLO crystals. This selection allowed the comparison between state-of-the-art calculations and experiment. Several computational aspects are tackled to define conditions where the results are converged with respect to the range of lattice summations, to the number of k-points in the first Brillouin zone, to the order of the multipole expansions for evaluating the long-range part of the electrostatic interactions, as well as to the atomic basis set size. A valence triple zeta basis set supplemented with polarization functions has been selected. Then, χ<sup>(2)</sup> calculations have been performed using a range of exchange-correlation functionals (XCFs). Results show the large impact of the amount of Hartree-Fock (HF) exchange on the amplitude but also on the sign on the χ<sup>(2)</sup> tensor components. To a given extent, these amplitude effects are consistent with results on molecules, but the sign reversal effects and the non-monotonic behavior of the χ<sup>(2)</sup> tensor components as a function of the amount of HF exchange are scarcely found for molecules. Then, using the recommended range-separated hybrid XCFs, the CPKS scheme leads to good agreement with experimental data for potassium dihydrogenophosphate, urea, and χ<sub>ZXX</sub> <sup>(2)</sup> of LiNbO<sub>3</sub>. The agreement is more questionable for χ<sub>ZZZ</sub> <sup>(2)</sup> of LiNbO<sub>3</sub> whereas it remains poor for ammonium dihydrogenophosphate and 2-methyl-4-nitroaniline, with large underestimations by about a factor of 3, opening a path to further fine-tuning of the ranges of inclusion of HF exchange. Second-harmonic generation ; Materials science ; Chemistry ; Physics ; Optics ; Laser Nonlinear Optical Materials Research ; Crystallography and molecular interactions ; Spectroscopy and Quantum Chemical Studies
Authors: Jintana Siriboon | Nisanart Traiphol | Rakchart Traiphol
Source: Materials Today Chemistry (article, 2023-07-27)
Field: Chemistry — Organic Chemistry

ZnO quantum dots-diacetylenes-zinc(II) nanocomposites for colorimetric detection of ultraviolet-B light: the size effects Diacetylene ; Nanocomposite ; Ultraviolet ; Polydiacetylenes ; Materials science ; Quantum dot ; Monomer ; Nanoparticle ; Zinc ; Colorimetry ; Optoelectronics ; Ultraviolet light ; Nanotechnology ; Chemistry ; Polymer ; Composite material ; Chromatography Polydiacetylene-based materials and applications ; Ocular Surface and Contact Lens ; Nanoplatforms for cancer theranostics