jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Matthew D. Flamini | Mohamad Keblawi | Thamires A. Lima | Robert V. Chimenti | Nicolas J. Alvarez | Vince Beachley
Source: Advanced Materials Technologies (article, 2024-12-14)
Field: Materials Science — Biomaterials

Novel Use of Laser Zone‐Drawing on Nanofibers Enables Ultra‐Fast Thermal Kinetics and Precise Diameter Control Abstract Laser zone‐drawing is shown to significantly enhance control over nanofiber properties. This study investigates the dynamics of nanofiber laser zone‐drawing. It is hypothesized that the equilibrium between heating and cooling guides fiber temperature. The high heating rate of laser irradiation and the high convective cooling rate of nanofibers facilitate fast heating and cooling kinetics. Results showed fiber thinning in the presence of laser irradiation until reaching a steady‐state diameter. Final fiber diameter is correlated to laser power independent of initial fiber diameter. The relationship between final fiber diameter and laser power is used to estimate the heat transfer coefficient, which is used to create a computational model of the thermodynamic system. These simulations predict rapid heating and cooling up to 36 000 K min −1 for the lowest fiber diameters tested experimentally. While laser‐induced softening of polymer nanofibers is described in detail, the forces driving fiber drawing, particularly under different thermal kinetics, remain unexplored. This research showcases the capabilities of laser zone‐drawing in nanofiber manufacturing and facilitates future investigations aimed at enhancing fiber processing by producing highly aligned molecular structures via rapid cooling. This work signifies a pivotal methodological leap, promising transformative nanofiber materials useful across multiple industries including aerospace, electronics, and biomedicine. Materials science ; Kinetics ; Thermal ; Laser ; Nanofiber ; Nanotechnology ; Composite material ; Optics ; Thermodynamics ; Physics Electrospun Nanofibers in Biomedical Applications ; Surface Modification and Superhydrophobicity ; Polymer Nanocomposite Synthesis and Irradiation
Authors: Chase Brooks | Stephan Lany
Source: Physical Review Materials (article, 2024-06-18)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Heterostructural alloy phase diagram for (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Cd</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mi>Zn</mml:mi><mml:mi>x</mml:mi></mml:msub><mml:msub><mml:mrow><mml:mo>)</mml:mo></mml:mrow><mml:mn>3</mml:mn></mml:msub><mml:msub><mml:mi>As</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math> Alloying the topological semimetal ${\mathrm{Cd}}_{3}{\mathrm{As}}_{2}$ with ${\mathrm{Zn}}_{3}{\mathrm{As}}_{2}$ provides a potential route for controlling the electronic properties. We predict the alloy phase diagram from first-principles calculations, considering that both end members have a crystal structure derived from the antifluorite lattice, but with different arrangements of the unoccupied cation sites. To overcome the limitations of the regular solution approximation and to include short-range order effects, we perform Monte Carlo simulations, parameterize the temperature dependence of the mixing enthalpy $\mathrm{\ensuremath{\Delta}}{H}_{\mathrm{m}}$, and perform thermodynamic integration of the free energy. The resulting phase diagram exhibits features that are unique to heterostructural alloy systems and provides computational predictions of solubility limits and composition ranges that are stable against spinodal decomposition. Phase diagram ; Materials science ; Spinodal decomposition ; Alloy ; Thermodynamics ; Solubility ; Solid solution ; Crystal structure ; Enthalpy ; Order (exchange) ; Crystallography ; Phase (matter) ; Condensed matter physics ; Physics ; Physical chemistry ; Chemistry ; Metallurgy ; Quantum mechanics Iron-based superconductors research ; Rare-earth and actinide compounds ; Physics of Superconductivity and Magnetism
Authors: Djordje Došenović | Samuel Dechamps | Kshipra Sharma | Jean‐Luc Rouvière | Yiran Lu | M. den Hertog | Luigi Genovese | Simon M.‐M. Dubois | Jean‐Christophe Charlier | Matthieu Jamet | A. Marty | Hanako Okuno
Source: ACS Nano (article, 2024-08-15)
Field: Materials Science — Materials Chemistry

Imaging Negative Charge around Single Vanadium Dopant Atoms in Monolayer Tungsten Diselenide Using 4D Scanning Transmission Electron Microscopy There has been extensive activity exploring the doping of semiconducting two-dimensional (2D) transition metal dichalcogenides in order to tune their electronic and magnetic properties. The outcome of doping depends on various factors, including the intrinsic properties of the host material, the nature of the dopants used, their spatial distribution, as well as their interactions with other types of defects. A thorough atomic-level analysis is essential to fully understand these mechanisms. In this work, the vanadium-doped WSe<sub>2</sub> monolayer grown by molecular beam epitaxy is investigated using four-dimensional scanning transmission electron microscopy (4D-STEM). Through center-of-mass-based reconstruction, atomic-scale maps are produced, allowing the visualization of both the electric field and the electrostatic potential around individual V atoms. To provide quantitative insights, these results are successfully compared to multislice image simulations based on ab initio calculations, accounting for lens aberrations. Finally, a negative charge around the V dopants is detected as a drop in the electrostatic potential, unambiguously demonstrating that 4D-STEM can be used to detect and to accurately analyze single-dopant charge states in semiconducting 2D materials. Tungsten diselenide ; Materials science ; Transmission electron microscopy ; Dopant ; Monolayer ; Scanning transmission electron microscopy ; Vanadium ; Energy filtered transmission electron microscopy ; Diselenide ; Tungsten ; Microscopy ; Scanning electron microscope ; Doping ; Scanning confocal electron microscopy ; Charge (physics) ; Electron microscope ; Nanotechnology ; Optoelectronics ; Chemistry ; Optics ; Transition metal ; Catalysis ; Physics 2D Materials and Applications ; Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films
Authors: Umberto Contaldo | Anne de Poulpiquet | Ievgen Mazurenko | Élisabeth Lojou
Source: Electrochemistry (article, 2024-01-23)
Field: Chemistry — Electrochemistry

Electrode Nanopatterning for Bioelectroanalysis and Bioelectrocatalysis Although intensive research in the bioelectroanalysis domain in the last twenty years led to great improvements in protein-based electrode and device performances, their large application remains limited by their stability overtime under operational and resting conditions. One under-studied issue is the role played by the spatial distribution of enzymes on electrocatalysis. Actually, high fluxes in metabolic pathways involve compartmentalization and spatial organization of active biomolecules. In a mimicking way, it can be expected that controlled localization of proteins on electrode surfaces may play a role in the overall electron transfer processes and bioelectrocatalysis performances. In this short review, we will discuss recent developments in surface patterning allowing to tune in a controlled manner the localization and density of enzymes on the electrode surface. We will investigate how mixed functional layers, electrode and biological materials can serve as protein platforms to provide such electrode patterning. Materials science ; Electrode ; Nanotechnology ; Optoelectronics ; Chemistry ; Physical chemistry Electrochemical Analysis and Applications ; Electrochemical sensors and biosensors ; Advanced biosensing and bioanalysis techniques
Authors: Peter Fritz | Hanan AlHamwi | Alexander Villinger | Dirk Michalik | Jonas Bresien | Fabian Reiß | Torsten Beweries | Axel Schulz
Source: Chemistry - A European Journal (article, 2024-06-25)
Field: Chemistry — Organic Chemistry

A Phosphorus‐Centred, Zirconocene‐Bridged Tetraradical: Synthesis, Structure and Application as Molecular Double Switch Biradicals are important intermediates in the formation and breaking of a chemical bond. Their use as molecular switches is of particular interest. Much less is known about tetraradicals, which can, for example, consist of two biradical(oid) units. Here we report the synthesis of the first persistent phosphorus-centred tetraradical bound to a transition metal fragment. Starting from a zirconocene complex, rac-(ebthi)ZrCl<sub>2</sub> (rac-(ebthi)=1,2-ethylene-1,10-bis(η<sup>5</sup>-tetrahydroindenyl), two cyclo-1,3-diphospha-pentane-1,3-diyls were successfully introduced, which finally led to the isolation of a deep green zirconcene-bridged bis(biradicaloid) complex (5) that can act as a double molecular switch. Under the influence of light (570 nm), this tetraradical forms a transannular bond in each of the two five-membered biradical units, leading to the formation of housane 5 h. Upon irradiation at 415 nm, the reverse reaction is observed, fully recovering tetraradical 5. Through single-crystal-to-single-crystal transformation, both stable species of the molecular switch could be structurally characterised using SCXRD. The switching under the influence of light and the activation of molecular hydrogen were analysed in solution using NMR and UV spectroscopy. It was found that the addition of one or two equivalents of molecular hydrogen can be switched on and off by light. Phosphorus ; Materials science ; Chemistry ; Crystallography ; Organic chemistry Organometallic Complex Synthesis and Catalysis ; Magnetism in coordination complexes ; Porphyrin and Phthalocyanine Chemistry
Authors: Veronika Richterová | Miloslav Pekař
Source: Gels (article, 2024-09-24)
Field: Materials Science — Biomaterials

Effect of Silk Fibroin on the Mechanical and Transport Properties of Agarose Hydrogels In this work, the effect of incorporating silk fibroin, a fibrous biocompatible protein, into physically cross-linked agarose hydrogels was investigated as a simple model study to examine how supramolecular fibrous structures influence the properties of the hydrogels. The rheological and transport properties were studied. Fibroin did not change the general viscoelastic properties of the investigated hydrogels but changed the viscoelastic moduli values and also the mesh size, as calculated from rheometry data. Fibroin influenced the mechanical properties depending on its concentration: at lower concentrations, it increased the mesh size, while at higher concentrations, it acted as a filler, decreasing the mesh size. Similarly, the storage and loss moduli were affected, either increasing or decreasing based on the fibroin concentration. The fibroin effect on the diffusion of two dyes differing in their charge was the result of a combination of structural effects, responsible also for changes in the rheological properties, and a result of electrostatic interactions between the charged groups. For positively charged methylene blue, low fibroin concentrations accelerated diffusion, while higher concentrations slowed it by filling network vacancies. In contrast, for negatively charged eosin-B, fibroin strongly impeded diffusion at all concentrations due to electrostatic repulsion, leading to its accumulation at the hydrogel interface. The findings of this work may contribute to an understanding of the behavior of the extracellular matrix or soft tissues as well as to the development of the tailored design of hydrogel materials. Fibroin ; Self-healing hydrogels ; Rheology ; Viscoelasticity ; Materials science ; Rheometry ; Dynamic mechanical analysis ; Chemical engineering ; Agarose ; Diffusion ; Composite material ; Polymer chemistry ; Polymer ; Chemistry ; SILK ; Chromatography Silk-based biomaterials and applications ; Hydrogels: synthesis, properties, applications ; Collagen: Extraction and Characterization
Authors: Vincent Varanges | Vijay Kumar Rana | Valentin Phillippe | P.‐E. Bourban | Dominique P. Pioletti
Source: ACS Applied Engineering Materials (article, 2024-09-27)
Field: Materials Science — Polymers and Plastics

Development and Performance Evaluation of Hybrid Iono-organogels for Efficient Impact Mitigation Dissipative materials are essential for mitigating impact in various automotive, aerospace, and sports equipment applications. This study investigates the efficiency of a novel hybrid iono-organogel in dissipating and absorbing impact energies. The gel consists of a covalently cross-linked poly(acrylic acid)-<i>co</i>-poly(zwitterionic (DMAPS)) in a hybrid solvent system composed of the ionic liquid [C<sub>2</sub>OHMIM][BF<sub>4</sub>] and the oligomer PEG200. The optimal solvent hybridization ratio for achieving the lowest deceleration during impact testing is 40 vol % of the ionic liquid and 60 vol % of PEG200. The gel exhibits efficient mechanical dissipative properties with a loss factor exceeding 0.5 when solicited under various dynamic conditions with this optimized ratio. Moreover, the gel demonstrates high strength and toughness, enabling it to withstand impacts without experiencing catastrophic failure. The developed gel presents stable mechanical properties over broad temperature (0-100 °C) and frequency (0.01-2000 Hz) ranges. It maintains its performance during successive impacts, thanks to its self-recovery abilities. The remarkable mechanical properties of the gel are attributed to the abundance of combined functional groups within the gel polymeric network. Indeed, reversible H-bonds, ion-dipole, and dipole-dipole interactions were observed in different studies to enhance mechanical performance. Their unique synergy effect in the developed hybrid gels held promise for better control of impact properties and durability in numerous dynamic applications. Environmental science Polymer composites and self-healing ; Polymer Nanocomposites and Properties ; Advanced Sensor and Energy Harvesting Materials
Authors: Xinli Jia | Peiwen Xiao | Liqiang Yang | Jianhui Luo | Meiying He | Pingmei Wang | Bo Jiang | Bo Xiao
Source: Materials (article, 2024-03-08)
Field: Materials Science — Materials Chemistry

Preparation of Asymmetric Al2O3-SiO2 Janus Nanoparticles in Aqueous Phase and Its Interfacial Property In this study, asymmetric Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub> Janus nanoparticles with a dumbbell-like structure were synthesized by a facile chemical process in the aqueous phase. Prior to synthesis, Al<sub>2</sub>O<sub>3</sub> nanoparticles in hydrosol were amino-modified using 3-aminopropyl triethoxysilane (KH550) and then carboxyl acid-functionalized using a ring-opening reaction of the amine functions with succinic anhydride, imparting unique anionic properties to the Al<sub>2</sub>O<sub>3</sub> end. SiO<sub>2</sub> nanoparticles were rendered hydrophobic through modification with hexamethyldisilazane (HMDS) and further functionalized with 3-chloropropyl triethoxysilane (KH230). The two nanoparticle hydrosols were then mixed, and the asymmetric Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub> Janus nanoparticles were synthesized via the reaction between the -NH<sub>2</sub> and -CH<sub>2</sub>Cl groups. The prepared Janus nanoparticles were primarily characterized by dynamic light scattering (DLS), Zeta potential (ZP), and transmission electron microscopy (TEM). The results indicated that about 90% of the modified Al<sub>2</sub>O<sub>3</sub> and SiO<sub>2</sub> nanoparticles were covalently coupled in a one-to-one manner to form the dominant dumbbell-like structure. These Janus nanoparticles exhibit amphiphilic properties, making them highly promising surfactants for emulsifying oil-water mixtures. Succinic anhydride ; Triethoxysilane ; Nanoparticle ; Janus ; Materials science ; Zeta potential ; Chemical engineering ; Dynamic light scattering ; Aqueous solution ; Janus particles ; Amphiphile ; Aqueous two-phase system ; Phase (matter) ; Polymer chemistry ; Organic chemistry ; Nanotechnology ; Chemistry ; Copolymer ; Polymer Pickering emulsions and particle stabilization ; Surfactants and Colloidal Systems ; Enhanced Oil Recovery Techniques
Authors: Kitti Franciska Szabó | Piotr Banachowicz | Antoni Powała | Ignacio Funes‐Ardoiz | Dorota Gryko
Source: ChemRxiv (preprint, 2024-07-11)
Field: Chemistry — Organic Chemistry

Photochemical C3-Amidation of Pyridines via Zincke Imine Intermediates Selective skeletal and peripheral editing of the pyridine moiety broadly expanded the chemical space. While CH functionalizations at the positions C2 and C4 are enabled by the inherent reactivity of this heteroarene, selective derivatization at C3 has long posed a significant challenge. Recently, based on dearomatization-rearomatization sequence, involving Zincke imine intermediates, selective halogenation (-Br, -Cl, -I) and isotopic labelling was accomplished. Here, we report a mild and regioselective method for C3 amination that relies on the photochemical reaction of Zincke imine with an amidyl radical generated from N-aminopyridinium salts. Mechanistic and theoretical studies confirmed radical intermediates involved and explains C-3 regioselectivity of the reaction. Imine ; Chemistry ; Photochemistry ; Organic chemistry ; Catalysis Catalytic C–H Functionalization Methods ; Synthesis and Catalytic Reactions ; Chemical Synthesis and Reactions
Authors: Razan E. Daoud | Roberto Cacciari | Luca De Vico
Source: The Journal of Physical Chemistry A (article, 2024-10-21)
Field: Materials Science — Materials Chemistry

Multiconfigurational Excitonic Couplings in Homo- and Heterodimer Stacks of Azobenzene-Derived Dyes Molecular excitons play a major role within dye aggregates and hold significant potential for (opto)electronic and photovoltaic applications. Numerous studies have documented alterations in the spectral properties of dye homoaggregates, but only limited work has been reported for heteroaggregates. In this article, dimeric dye stacks were constructed from azobenzene-like dyes with identical or distinct structures, and their excitonic features were computationally investigated. Our results show that strong exciton coupling is not limited to identical chromophores, as often assumed, based on a recently made available Frenkel Exciton Hamiltonian and multiconfigurational plus second-order perturbation theory energetics methodology. Heteroaggregate stacks were found to exhibit different absorption features from the corresponding interacting monomers, indicating considerable coupling interactions between units. We analyzed how such coupling may vary according to various aspects, such as the relative positions of the interacting monomers or the differences in their energetics. Such qualitative and semiquantitative analyses allow the evaluation of the excitonic behavior of these dye aggregates to encourage further efforts toward a deeper understanding of the excitonic properties of tailored dye heteroaggregate systems. Azobenzene ; Materials science ; Optoelectronics ; Physics ; Photochemistry ; Chemistry ; Chemical physics ; Quantum mechanics ; Molecule Photochromic and Fluorescence Chemistry ; Luminescence and Fluorescent Materials ; Supramolecular Self-Assembly in Materials
Authors: Nigus Maregu Demewoz
Source: Advances in Polymer Technology (article, 2024-01-01)
Field: Materials Science — Polymers and Plastics

Insights into Factors Influencing Thermoplastic Elastomer (TPE) Foam Production and the Role of Induced Crystallization This review provides a comprehensive overview of the multifaceted factors influencing TPE foam production, with a specific focus on the intriguing role of induced crystallization. TPE foams excel in versatility and cost‐effectiveness, yet their production faces several challenges, that significantly impact their final characteristics. The examination encompasses a range of factors, including solubility, diffusivity, interfacial tension, rheology, foaming parameters, nucleating agents, and the intricate influence of induced crystallization on TPE foam structure and performance. In TPE, crystallinity can be induced through various means including gas sorption, stress concentration, extrusion, annealing, and self‐nucleation. These induced crystals serve as nucleation sites for heterogeneous nucleation during foaming. The advancements achieved in polymer foam are thoroughly evaluated in terms of both progress and limitations, drawing insights from various research findings. Furthermore, the review examines recent developments and explores the effects of induced crystallization on TPE foam. Materials science ; Crystallization ; Thermoplastic elastomer ; Composite material ; Elastomer ; Thermoplastic ; Polymer science ; Chemical engineering ; Copolymer ; Polymer Polymer Foaming and Composites ; biodegradable polymer synthesis and properties ; Polymer composites and self-healing
Authors: Carolina Méndez‐Gálvez | Boris Olsthoorn | Fredrik Barnå | David Estébanez Rosich | Paul J. Gates | Lukasz T. Pilarski
Source: ChemRxiv (preprint, 2024-03-31)
Field: Chemistry — Inorganic Chemistry

Grind-and-Heat: Solvent-free Catalytic C–H and C–X Functionalization Without a Ball Mill This study describes an accessible approach to various solvent-free transition metal-catalyzed C–H and C–X functionalizations. Conditions from eight different Rh-, Ru-, Ir- and Pd-based mechanochemical reactions are adapted to proceed with generally high efficiency by substituting automated ball milling with pestle and mortar grinding and subsequent heating. This is a low-cost, operationally simple method that requires no specialized equipment and offers similar sustainability benefits. The reaction scope encompasses 10 heterocycle types, many pendant functional groups and is demonstrated on the late-stage modification of a variety of bioactive compounds. Grind ; Ball mill ; Surface modification ; Mill ; Catalysis ; Ball (mathematics) ; Materials science ; Chemical engineering ; Metallurgy ; Chemistry ; Organic chemistry ; Mechanical engineering ; Mathematics ; Engineering ; Grinding Asymmetric Hydrogenation and Catalysis ; Catalytic C–H Functionalization Methods ; Catalytic Processes in Materials Science
Authors: Samuel PANTALEO | Florent Gauvin | Katrin Schollbach | H.J.H. Brouwers
Source: Developments in the Built Environment (article, 2024-11-20)
Field: Chemistry — Spectroscopy

Development of latex / silica aerogel composites for thermal insulation applications Silica aerogel stands out as an exceptional thermal insulation material and is a great candidate for modern and energy-efficient buildings. However, silica aerogel also faces many challenges, mainly due to its expensive, unsustainable and difficult synthesis process, but also its poor structural properties. Consequently, the main research focus for silica aerogel is to mitigate its brittleness in order to pave the way for broader applications, especially in the building field. Therefore, this study focuses on the development of composite materials aiming at solving the abovementioned drawbacks of silica aerogel, by using environmentally friendly latexes and reinforcement that are easy to process. Results show the positive effect of this reinforcement, even at a small amount (5% volume), on the composite's properties, with thermal conductivity at least equivalent, or better, to either in development or already established insulation materials in the market. • The use of silica aerogel composites as building materials for building energy efficiency. • A solvent-free, less water demanding and easy to process material. • An evaluation of thermal conductivity and mechanical properties of the composites following a chemical addition to enhance the compatibility between matrix and filler. • An assessment of the impact of the matrices and the effect of the addition of the enhancer on the properties. • A material development aimed for refurbishment of existing buildings. Aerogel ; Composite material ; Materials science ; Thermal insulation ; Thermal Aerogels and thermal insulation ; Silicone and Siloxane Chemistry ; Surface Modification and Superhydrophobicity