jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: María Elena Sánchez Vergara | Luis Alberto Cantera-Cantera | Citlalli Ríos | Roberto Salcedo | O. Flores | Ateet Dutt
Source: Sensors (article, 2023-09-06)
Field: Materials Science — Polymers and Plastics

Preparation of Hybrid Films Based in Aluminum 8-Hydroxyquinoline as Organic Semiconductor for Photoconductor Applications In the present work, we have investigated an organic semiconductor based on tris(8-hydroxyquinoline) aluminum (AlQ<sub>3</sub>) doped with tetracyanoquinodimethane (TCNQ), which can be used as an organic photoconductor. DFT calculations were carried out to optimize the structure of semiconductor species and to obtain related constants in order to compare experimental and theoretical results. Subsequently, AlQ<sub>3</sub>-TCNQ films with polypyrrole (Ppy) matrix were fabricated, and they were morphologically and mechanically characterized by Scanning Electron Microscopy, X-ray diffraction and Atomic Force Microscopy techniques. The maximum stress for the film is 8.66 MPa, and the Knoop hardness is 0.0311. The optical behavior of the film was also analyzed, and the optical properties were found to exhibit two indirect transitions at 2.58 and 3.06 eV. Additionally, photoluminescence measurements were carried out and the film showed an intense visible emission in the visible region. Finally, a photoconductor was fabricated and 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=4.4586×10191m3 and Nt=3.1333×10311m3, respectively. Materials science ; Ohmic contact ; Photoluminescence ; Organic semiconductor ; Semiconductor ; Scanning electron microscope ; Optoelectronics ; Thin film ; Analytical Chemistry (journal) ; Nanotechnology ; Chemistry ; Composite material Conducting polymers and applications ; Organic Electronics and Photovoltaics ; Organic Light-Emitting Diodes Research
Authors: Javier Macías | J.R. Frade | Aleksey A. Yaremchenko
Source: Materials (article, 2023-12-14)
Field: Materials Science — Materials Chemistry

SrTiO3-SrVO3 Ceramics for Solid Oxide Fuel Cell Anodes: A Route from Oxidized Precursors Perovskite-type Sr(Ti,V)O3-δ ceramics are promising anode materials for natural gas- and biogas-fueled solid oxide fuel cells, but the instability of these phases under oxidizing conditions complicates their practical application. The present work explores approaches to the fabrication of strontium titanate-vanadate electrodes from oxidized precursors. Porous ceramics with the nominal composition SrTi1−yVyOz (y = 0.1–0.3) were prepared in air via a solid state reaction route. Thermal processing at temperatures not exceeding 1100 °C yielded composite ceramics comprising perovskite-type SrTiO3, pyrovanadate Sr2V2O7 and orthovanadate Sr3(VO4)2 phases, while increasing firing temperatures to 1250–1440 °C enabled the formation of SrTi1−yVyO3 perovskites. Vanadium was found to substitute into the titanium sublattice predominantly as V4+, even under oxidizing conditions at elevated temperatures. Both perovskite and composite oxidized ceramics exhibit moderate thermal expansion coefficients in air, 11.1–12.1 ppm/K at 30–1000 °C, and insignificant dimensional changes induced by reduction in a 10%H2-N2 atmosphere. The electrical conductivity of reduced perovskite samples remains comparatively low, ~10−1 S/cm at 900 °C, whereas the transformation of oxidized vanadate phases into high-conducting SrVO3−δ perovskites upon reduction results in enhancement in conductivity, which reaches ~3 S/cm at 900 °C in porous composite ceramics with nominal composition SrTi0.7V0.3Oz. The electrical performance of the composite is expected to be further improved by optimization of the processing route and microstructure to facilitate the reduction of the oxidized precursor and attain better percolation of the SrVO3 phase. Materials science ; Perovskite (structure) ; Ceramic ; Oxidizing agent ; Strontium titanate ; Vanadium ; Oxide ; Vanadate ; Composite number ; Chemical engineering ; Microstructure ; Solid oxide fuel cell ; Inorganic chemistry ; Anode ; Composite material ; Metallurgy ; Electrode ; Nanotechnology ; Chemistry ; Thin film ; Physical chemistry ; Organic chemistry Advancements in Solid Oxide Fuel Cells ; Electronic and Structural Properties of Oxides ; Magnetic and transport properties of perovskites and related materials
Authors: Claire Meyer | Patrick Davidson | Geoffrey R. Luckhurst | Irena Dokli | Anamarija Knežević | Andreja Lesac | Daniel A. Paterson | Rebecca Walker | John M. D. Storey | Corrie T. Imrie | I. Dozov
Source: Crystals (article, 2023-03-08)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Temperature Dependence of the Electroclinic Effect in the Twist-Bend Nematic Phase The twist-bend nematic (NTB) phase of bent-shaped molecules has recently attracted much attention due to the spontaneous bend of its director field and the doubly-degenerate chirality of its heliconical structure. Despite intensive experimental and theoretical investigation worldwide, the main structural characteristics (pitch and conical angle) and elastic properties of the phase are still barely understood. This is mainly due to the difficulty in growing large single domains of the NTB phase, which prevents the application of the powerful electro-optical techniques developed for the nematic (N) phase. Moreover, the twist and bend distortions of the optic axis are forbidden by the pseudo-layered structure of the NTB phase, which makes its response to the field smectic-like instead of nematic-like. Therefore, the only macroscopic electric effect that can be observed deep in the NTB phase is the smectic-like “electroclinic” effect (ECENTB). Here, we achieve large monochiral NTB domains which remain uniform over a wide temperature range (20–60 °C) in thin (1.5 µm) planar cells, thus avoiding the so-called stripe- and rope-like textural instabilities. This allowed us to experimentally determine, using electro-optical measurements, the temperature dependence of the ECENTB response in four different NTB materials: namely the dimers CB7CB, CB9CB, CB6OCB, and BNA76. For all compounds, the thermal dependences of conical angle and pitch in the vicinity of the N-NTB transition follow the theoretically predicted power law behaviour. However, the agreement between the measured and predicted power law exponents remains only qualitative, which calls for improvement of the theoretical models. Liquid crystal ; Conical surface ; Phase (matter) ; Materials science ; Twist ; Condensed matter physics ; Phase transition ; Optics ; Power law ; Physics ; Optoelectronics ; Composite material ; Geometry Liquid Crystal Research Advancements ; Photonic Crystals and Applications ; Synthesis and Properties of Aromatic Compounds
Authors: Prashant Singh
Source: Scripta Materialia (article, 2023-07-06)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Role of spin-orbit coupling on crystal-field splitting and phase-stability of rare-earth based layered intermetallic Materials science ; Condensed matter physics ; Heterojunction ; Intermetallic ; Density functional theory ; Crystal (programming language) ; Fermi level ; Superconductivity ; Phase (matter) ; Chemistry ; Computational chemistry ; Physics ; Electron Iron-based superconductors research ; 2D Materials and Applications ; MXene and MAX Phase Materials
Authors: Chloé Andrade | Saly Hawila | Ahmad Abdallah | Jean-Luc Rukemampunzi | Adel Mesbah | Nathalie Guillou | Florent Perret | Stefan Wuttke | Thomas A. Niehaus | Régis Debord | Olivier Boisron | S. Pailhès | Aude Demessence
Source: Journal of Materials Chemistry C (article, 2023-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

A p-type semi-conducting copper(<scp>i</scp>)-1,3-benzenedithiolate 2D coordination polymer with high Seebeck coefficient A p-type semi-conducting and 2D coordination polymer, made of 1D copper( i )–sulfur inorganic networks, exhibits very high Seebeck coefficient for thermoelectricity. Seebeck coefficient ; Copper ; Materials science ; Thermoelectric effect ; Polymer ; Coordination polymer ; Sulfur ; Metallurgy ; Composite material ; Thermodynamics ; Thermal conductivity ; Physics Organic and Molecular Conductors Research ; Metal-Organic Frameworks: Synthesis and Applications ; Advanced Thermoelectric Materials and Devices
Authors: Thomas P. Nicholls | Zhongfan Jia | Justin M. Chalker
Source: Chemistry - A European Journal (article, 2023-10-24)
Field: Chemistry — Organic Chemistry

Electrochemical Synthesis of Gold‐ <i>N</i> ‐Heterocyclic Carbene Complexes** An electrochemical synthesis of gold(I)-N-heterocyclic carbene (Au-NHC) complexes has been developed. The electrochemical methodology uses only imidazolium salts, gold metal electrodes, and electricity to produce these complexes with hydrogen gas as the only by-product. This high-yielding and operationally simple procedure has been used to produce eight mononuclear and three dinuclear Au-NHC complexes. The electrochemical procedure facilitates a clean reaction with no by-products. As such, Au-NHC complexes can be directly transferred to catalytic reactions without work-up or purification. The Au-NHC complexes were produced on-demand and tested as catalysts in a vinylcyclopropanation reaction. All mononuclear Au-NHC complexes performed similarly to or better than the isolated complexes. Carbene ; Electrochemistry ; Catalysis ; Chemistry ; Combinatorial chemistry ; Metal ; Electrode ; Organic chemistry ; Medicinal chemistry ; Polymer chemistry ; Physical chemistry N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Catalytic Cross-Coupling Reactions ; Catalytic Alkyne Reactions
Authors: Joe Willis | Romain Claes | Qi Zhou | Matteo Giantomassi | Gian‐Marco Rignanese | Geoffroy Hautier | David O. Scanlon
Source: ChemRxiv (preprint, 2023-06-26)
Field: Materials Science — Materials Chemistry

Limits to Hole Mobility and Doping in Copper Iodide Over one hundred years have passed since the discovery of the p-type transparent conducting material copper iodide, pre-dating the concept of the ``electron-hole'' itself. Supercentenarian status notwithstanding, little is understood about the charge transport mechanisms in \ce{CuI}. Herein, a variety of modelling techniques are used to investigated the charge transport properties of \ce{CuI}, and limitations to the hole mobility over experimentally achievable carrier concentrations are discussed. Poor dielectric response is responsible for extensive scattering from ionised impurities at degenerately doped carrier concentrations, while phonon scattering is found to dominate at lower carrier concentrations. A phonon-limited hole mobility of \SI{162}{\centi\meter\squared\per\volt\per\second} is predicted at room temperature. The simulated charge transport properties for \ce{CuI} are compared to existing experimental data and the implications for future device performance are discussed. In addition to charge transport calculations, the defect chemistry of \ce{CuI} is investigated with hybrid functionals, revealing that reasonably localised holes from the copper vacancy are the predominant source of charge carriers. The chalcogens S and Se are investigated as extrinsic dopants, where it is found that despite relatively low defect formation energies, they are unlikely to act as efficient electron acceptors due to strong localisation of holes and subsequent deep transition levels. Electron mobility ; Dopant ; Charge carrier ; Doping ; Impurity ; Scattering ; Materials science ; Copper ; Vacancy defect ; Iodide ; Electron ; Charge (physics) ; Condensed matter physics ; Phonon scattering ; Carrier scattering ; Electron hole ; Chemical physics ; Phonon ; Chemistry ; Optoelectronics ; Inorganic chemistry ; Physics ; Optics ; Metallurgy Copper-based nanomaterials and applications ; Quantum Dots Synthesis And Properties ; ZnO doping and properties
Authors: Andrés García‐Viada | Celia Sánchez‐González | Mario Martínez‐Mingo | Inés Alonso | Nuria Rodríguez | Juan C. Carretero
Source: Advanced Synthesis & Catalysis (article, 2023-10-12)
Field: Chemistry — Organic Chemistry

Pd‐Catalyzed δ‐C(<i>sp</i><sup>3</sup>)−H Thiolation of Amino Acid Derivatives Abstract Herein, we report a protocol for the selective δ‐thiolation of aliphatic α‐amino acids catalyzed by a Pd(II)/Ag(I) system. This reaction employs disulfides as thiolating agents and N ‐COPy as directing group, providing valuable non‐proteinogenic amino acid derivatives in moderate to good diastereoselectivities and yields. Remarkably, the method is also suitable for the late‐stage functionalization of a dipeptide. Experimental and DFT studies have provided significant insights into the mechanism and underlying factors controlling the selectivity of the process and determining the key role of the silver salt. Chemistry ; Dipeptide ; Catalysis ; Selectivity ; Amino acid ; Surface modification ; Salt (chemistry) ; Combinatorial chemistry ; Stereochemistry ; Organic chemistry ; Biochemistry Sulfur-Based Synthesis Techniques ; Chemical Synthesis and Reactions ; Catalytic C–H Functionalization Methods
Authors: Mengwen Yan | Liman Hou | Xianjun Deng | Xinyuan Shi | Feng Jiang | Mingfeng Wang
Source: Chemistry - A European Journal (article, 2023-12-27)
Field: Chemistry — Organic Chemistry

Anthraquinodimethane‐Based Molecular Switches Tethered by Four‐Arm Star‐like Polymers Abstract Molecular switches that reversibly change their structures and physical properties are important for applications such as sensing and information processing at molecular scales. In order to avoid the intermolecular aggregation that is often detrimental to the stimuli‐responses of molecular switches, previous studies of molecular switches have been often conducted in dilute solutions which are difficult for applications in solid‐state devices. Here we report molecular design and synthesis that integrates anthraquinodimethane as molecular switching units into polymers with amenable processibility in solid states. Optical and electron spin resonance characterizations indicate that the four‐arm polymers of poly(ϵ‐caprolactone) or poly(D,L‐lactide) tethered from anthraquinodimethane slow down the dynamics of the conformational switching between the folded and the twisted conformations, enhance the photoluminescence in solid states and impart materials with a small energy gap from singlet ground state to thermally accessible triplet state. Molecular switch ; Polymer ; Intermolecular force ; Materials science ; Singlet state ; Chemical physics ; Solid-state ; Photoluminescence ; Molecular wire ; Molecular dynamics ; Nanotechnology ; Molecule ; Chemistry ; Optoelectronics ; Computational chemistry ; Physics ; Excited state ; Physical chemistry ; Atomic physics ; Organic chemistry Supramolecular Chemistry and Complexes ; Luminescence and Fluorescent Materials ; Molecular Junctions and Nanostructures
Authors: Yosuke Akae | Jun Sawada | K. Nakajima | Toshikazu Takata
Source: Angewandte Chemie (article, 2023-05-10)
Field: Chemistry — Organic Chemistry

The Effect of the Axle End Structure and Number of Through‐Space Bonds on the Properties of Rotaxane Crosslinked Polymers Abstract A rotaxane crosslinker (RC) is known to toughen the resulting rotaxane crosslinked polymer (RCP) via a stress dispersion effect that is attributed to the movable nature of the crosslinking structure. To evaluate this toughening mechanism in detail, a series of structure‐definite RCs equipped with different axle end structures or different numbers of wheel components were synthesized, and subjected to free radical polymerization with a vinyl monomer to obtain RCPs. Analyses of the obtained RCPs revealed that the size of the axle end structure should be well‐balanced to produce a strong toughening effect, and a [3]rotaxane crosslinker works more effectively than [2]rotaxane to toughen RCPs. The mobility of the crosslinking points, in terms of rotational and flipping movements, was more crucial to toughening the RCP than that of translational movement along the axle. The first observation of the above crucial findings proved the utility of the systematic molecular design used in this study. Rotaxane ; Toughening ; Axle ; Materials science ; Polymer ; Monomer ; Composite material ; Chemical engineering ; Polymer chemistry ; Toughness ; Molecule ; Chemistry ; Organic chemistry ; Structural engineering ; Supramolecular chemistry Supramolecular Chemistry and Complexes ; Advanced Polymer Synthesis and Characterization ; Silicone and Siloxane Chemistry
Authors: Hualei Zhang | Xinlei Wang | Jie Zhou | Weihua Tang
Source: Molecules (article, 2023-11-08)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Azo-Linkage Redox Metal–Organic Framework Incorporating Carbon Nanotubes for High-Performance Aqueous Energy Storage The design of well-defined hierarchical free-standing electrodes for robust high-performance energy storage is challenging. We report herein that azo-linkage redox metal-organic frameworks (MOFs) incorporate single-walled carbon nanotubes (CNTs) as flexible electrodes. The in situ-guided growth, crystallinity and morphology of UiO-66-NO<sub>2</sub> MOFs were finely controlled in the presence of CNTs. The MOFs' covalent anchoring to CNTs and solvothermal grafting anthraquinone (AQ) pendants endow the hybrid (denoted as CNT@UiO-66-AQ) with greatly improved conductivity, charge storage pathways and electrochemical dynamics. The flexible CNT@UiO-66-AQ displays a highest areal specific capacitance of 302.3 mF cm<sup>-2</sup> (at 1 mA cm<sup>-2</sup>) in -0.4~0.9 V potential window, together with 100% capacitance retention over 5000 cycles at 5 mA cm<sup>-2</sup>. Its assembled symmetrical supercapacitor (SSC) achieves a maximum energy density of 0.037 mWh cm<sup>-2</sup> and a maximum power density of 10.4 mW cm<sup>-2</sup>, outperforming many MOFs-hybrids-based SSCs in the literature. Our work may open a new avenue for preparing azo-coupled redox MOFs hybrids with carbaneous substrates for high-performance robust aqueous energy storage. Supercapacitor ; Carbon nanotube ; Materials science ; Crystallinity ; Redox ; Capacitance ; Energy storage ; Chemical engineering ; Electrochemistry ; Nanotechnology ; Aqueous solution ; Electrode ; Carbon fibers ; Hybrid material ; Chemistry ; Composite number ; Organic chemistry ; Composite material Supercapacitor Materials and Fabrication ; Advanced battery technologies research ; Conducting polymers and applications
Authors: Tommaso Nicolini | Bernardo A. Frontana‐Uribe | Alexander Kuhn | Gerardo Salinas
Source: ChemElectroChem (article, 2023-10-04)
Field: Materials Science — Polymers and Plastics

Tuning the Electrochemical Properties of Poly‐thiophenes with a 2,5‐Dithienil‐N‐subtituted‐pyrrole Bearing an Aniline Moiety for Electrochromic Devices Abstract Conducting polymers find applications as active materials in electrochromic devices thanks to their tunable optoelectronic and electrochemical properties. Such versatility can be further enhanced by copolymerizing various aromatic monomers in order to produce new materials. In this work, we present different copolymers obtained by electropolymerization of an N‐substituted dithienylpyrrole (SNSBA) with either 3,4‐ethylendioxythiophene (EDOT) or bithiophene (BTh). The electrochemical, spectroscopic, and electrical properties were characterized across their different neutral and charged states by means of ex‐situ and in‐situ spectroelectrochemical techniques. The peculiar feature of SNSBA lies in the aniline bearing substituent of the central pyrrole unit that allows polymerization to occur at three different sites, yielding a cross‐linked polymer network. Our findings show that the SNSBA comonomer not only influences the optoelectronic properties of the final materials with respect to their homopolymers, but also induces a lowering of the hysteresis of the insulating/conducting transition ( ΔE G &lt;280 mV), likely due to the cross‐linked nature of the polymer layer. These features are promising to develop a new class of copolymers for electrochromic devices with stable, reversible, and fast operation. Electrochromism ; Materials science ; Comonomer ; Substituent ; Aniline ; Copolymer ; Monomer ; Electrochemistry ; Polymerization ; Polymer ; Electrochromic devices ; Conductive polymer ; Polymer chemistry ; Moiety ; Thiophene ; Chemical engineering ; Electrode ; Organic chemistry ; Chemistry ; Physical chemistry ; Composite material Conducting polymers and applications ; Organic Electronics and Photovoltaics ; Transition Metal Oxide Nanomaterials
Authors: Liao Ai-hua | Wei Du | Huanghao Yang
Source: Analysis & Sensing (article, 2023-09-25)
Field: Chemistry — Organic Chemistry

The Inverse Electron Demand Diels‐Alder Reaction Between Tetrazine and Trans‐Cyclooctene for Pretargeted Bioimaging Applications Abstract Over the past few decades, pretargeted bioimaging has made significant contributions to disease diagnosis and the real‐time visualization of biological processes. Notably, the inverse electron demand Diels‐Alder (IEDDA) reaction between tetrazine (Tz) and trans ‐cyclooctene (TCO) has shown enormous potential in pretargeted bioimaging applications by capitalizing on its rapid kinetics, specific reactivity, biorthogonality and biocompatibility. To date, imaging probes based on the Tz−TCO click reaction have been extensively developed and widely used for pretargeted bioimaging applications. In this review, we focus on the Tz−TCO click reaction and summarize its applications in pretargeted bioimaging. Firstly, the fundamental principles for designing imaging probes based on the Tz−TCO click reaction are explained. Then, recent advances in imaging probes based on the Tz−TCO click reaction are discussed in detail. Finally, the current challenges and perspectives of the Tz−TCO click reaction in pretargeted bioimaging applications are presented. Tetrazine ; Click chemistry ; Cyclooctene ; Bioorthogonal chemistry ; Radiological imaging ; Computer science ; Nanotechnology ; Chemistry ; Materials science ; Combinatorial chemistry ; Organic chemistry ; Medicine ; Surgery ; Catalysis Click Chemistry and Applications ; Advanced biosensing and bioanalysis techniques ; Advanced Biosensing Techniques and Applications