jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Alejandro Martínez Gordon | María Isabel Prieto Barrio | Alfonso Cobo Escamilla
Source: Nanotechnology Reviews (article, 2023-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Graphene nanofibers: A modern approach towards tailored gypsum composites Abstract Energy poverty is a global challenge that demands sustainable and affordable solutions. This study investigates the use of commercial graphene nanofibers (GNFs) as a reinforcing agent in gypsum composites for energy-efficient building retrofitting. The GNFs were manually dispersed in the gypsum matrix, and the composites were fabricated by casting and curing. The thermomechanical properties were systematically studied using various characterization techniques, including scanning electron microscopy, X-ray diffraction, and thermal analysis. The results show that the addition of 1% GNFs reduces the thermal conductivity of the composites by more than 40% and improves their flexural and compressive strength by up to 23 and 42%, respectively, compared to neat gypsum. The enhancements are attributed to the effective phonon scattering of the GNFs and their ability to act as crystal seeding sites, resulting in a denser and more homogeneous structure. The dynamic thermal analysis further demonstrates that the GNF-reinforced composites could reduce heating and cooling requirements by 14 and 11%, respectively, indicating their potential for energy-efficient building retrofitting. However, the cost effectiveness and safety issues of the GNF-reinforced composites should be carefully considered before their large-scale implementation. Achieving uniform dispersion of nanoparticles in high concentrations is also a significant challenge that will be addressed in future studies. Materials science ; Composite material ; Graphene ; Flexural strength ; Nanofiber ; Retrofitting ; Gypsum ; Compressive strength ; Scanning electron microscope ; Thermal conductivity ; Nanotechnology ; Structural engineering Supercapacitor Materials and Fabrication ; Graphene research and applications ; Smart Materials for Construction
Authors: Reddivari Muniramaiah | Nandarapu Purushotham Reddy | Rompivalasa Santhosh | Gouranga Maharana | Jean Maria Fernandes | Dilli Babu Padmanaban | M. Kovendhan | Ganapathy Veerappan | Gangalakurti Laxminarayana | Banavoth Murali | D. Paul Joseph
Source: physica status solidi (a) (article, 2023-05-20)
Field: Materials Science — Materials Chemistry

Anionic Fluorine and Cationic Niobium Codoped Tin Oxide Thin Films as Transparent Conducting Electrodes for Optoelectronic Applications Exploration of alternatives for supplementing indium tin oxide electrode is currently trending due to scarcity of indium, leading to a steep increase in the cost of related optoelectronic components. Codoping of niobium (Nb) and fluorine (F) into SnO 2 lattice as cationic and anionic dopants, respectively, is explored by spray deposition technique. A fixed 10 wt% F and varying Nb concentration from 0 to 5 wt% is incorporated into the SnO 2 lattice. X‐ray diffraction reveals substitution of Nb and F into the SnO 2 lattice without altering the structure. Optical transmittance is found to increase with Nb content up to 4% of Nb (77.59%), and it decreases thereafter. Scanning electron microscope and optical profiler imply a relatively smooth surface with sharp‐tipped particles which vary with Nb concentration. Sheet resistance decreases up to 3 wt% of Nb doping and increases thereafter. Contact angle measurement indicates that upon doping with Nb, the films turn hydrophilic. Among the deposited films, 4 wt% of Nb‐doped film shows the highest figure of merit of 5.01 × 10 −3 Ω −1 . The surface work function of the 4 wt% Nb‐doped SnO 2 film is 4,687.85 meV. The optimal films are tested as electrodes in dye‐sensitized solar cells and are discussed in detail. Materials science ; Tin oxide ; Niobium ; Doping ; Sheet resistance ; Dopant ; Indium tin oxide ; Electrode ; Tin ; Niobium oxide ; Indium ; Scanning electron microscope ; Thin film ; Transparent conducting film ; Analytical Chemistry (journal) ; Optoelectronics ; Nanotechnology ; Layer (electronics) ; Metallurgy ; Composite material ; Chemistry ZnO doping and properties ; Gas Sensing Nanomaterials and Sensors ; Ga2O3 and related materials
Authors: Lewis R. Blackburn | Luke T. Townsend | Malin C. Dixon Wilkins | Toshiaki Ina | Merve Kuman | Shi‐Kuan Sun | Amber R. Mason | Laura J. Gardner | Martin C. Stennett | Claire L. Corkhill | Neil C. Hyatt
Source: Scientific Reports (article, 2023-06-08)
Field: Materials Science — Materials Chemistry

Underpinning the use of indium as a neutron absorbing additive in zirconolite by X-ray absorption spectroscopy Indium (In) is a neutron absorbing additive that could feasibly be used to mitigate criticality in ceramic wasteforms containing Pu in the immobilised form, for which zirconolite (nominally CaZrTi<sub>2</sub>O<sub>7</sub>) is a candidate host phase. Herein, the solid solutions Ca<sub>1-x</sub>Zr<sub>1-x</sub>In<sub>2x</sub>Ti<sub>2</sub>O<sub>7</sub> (0.10 ≤ x ≤ 1.00; air synthesis) and Ca<sub>1-x</sub>U<sub>x</sub>ZrTi<sub>2-2x</sub>In<sub>2x</sub>O<sub>7</sub> (x = 0.05, 0.10; air and argon synthesis) were investigated by conventional solid state sintering at a temperature of 1350 °C maintained for 20 h, with a view to characterise In<sup>3+</sup> substitution behaviour in the zirconolite phase across the Ca<sup>2+</sup>, Zr<sup>4+</sup> and Ti<sup>4+</sup> sites. When targeting Ca<sub>1-x</sub>Zr<sub>1-x</sub>In<sub>2x</sub>Ti<sub>2</sub>O<sub>7</sub>, single phase zirconolite-2M was formed at In concentrations of 0.10 ≤ x ≤ 0.20; beyond x ≥ 0.20, a number of secondary In-containing phases were stabilised. Zirconolite-2M remained a constituent of the phase assemblage up to a concentration of x = 0.80, albeit at relatively low concentration beyond x ≥ 0.40. It was not possible to synthesise the In<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub> end member compound using a solid state route. Analysis of the In K-edge XANES spectra in the single phase zirconolite-2M compounds confirmed that the In inventory was speciated as trivalent In<sup>3+</sup>, consistent with targeted oxidation state. However, fitting of the EXAFS region using the zirconolite-2M structural model was consistent with In<sup>3+</sup> cations accommodated within the Ti<sup>4+</sup> site, contrary to the targeted substitution scheme. When deploying U as a surrogate for immobilised Pu in the Ca<sub>1-x</sub>U<sub>x</sub>ZrTi<sub>2-2x</sub>In<sub>2x</sub>O<sub>7</sub> solid solution, it was demonstrated that, for both x = 0.05 and 0.10, In<sup>3+</sup> was successfully able to stabilise zirconolite-2M when U was distributed predominantly as both U<sup>4+</sup> and average U<sup>5+</sup>, when synthesised under argon and air, respectively, determined by U L<sub>3</sub>-edge XANES analysis. Zirconolite ; XANES ; Materials science ; Indium ; Phase (matter) ; Extended X-ray absorption fine structure ; Spectroscopy ; Nuclear chemistry ; Analytical Chemistry (journal) ; Crystallography ; Absorption spectroscopy ; Chemistry ; Physics ; Metallurgy ; Organic chemistry Nuclear materials and radiation effects ; Radioactive element chemistry and processing ; Advanced Condensed Matter Physics
Authors: Seung‐Bae Jeon | Seung‐Jae Lee | Junsu Kim | Sungoh Eim | Wooseop Lee | Woo Hyun Nam | Jeong Gon Son | Du Yeol Ryu
Source: NPG Asia Materials (article, 2023-12-29)
Field: Materials Science — Materials Chemistry

Two-dimensional directed lamellar assembly in silicon- and fluorine-containing block copolymer with identical surface energies Abstract A block copolymer (BCP) with specific monomer structures of fluoroacrylate polymers was designed by exploiting the inorganic superhydrophobicity and low glass transition temperature of polydimethylsiloxane (PDMS). With the use of a fluorine-containing block providing a surface tension as low as that of PDMS (19.9 &lt; $$\gamma$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> &lt; 21.5 mN/m), PDMS- b -poly(2,2,3,3,3-pentafluoropropyl acrylate) (PDMS- b -PPeFPA) copolymer was synthesized to create a volume-symmetric lamellar structure. The compositional randomness of the BCP chains adsorbed onto the substrates provided well-balanced interfacial interactions toward the overlaid PDMS- b -PPeFPA ( $$\gamma$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> PDMS-ads ≈ $$\gamma$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> PPeFPA-ads ). Under this symmetric confinement with simultaneous dual neutral interfaces, lamellar microdomains with a sub-10 nm half-pitch feature size were successfully oriented perpendicular to the interfaces at room temperature. We showed the response of the BCP films to a lateral electric field, demonstrating that the perpendicular lamellae were adaptively aligned along the electric vector within a short treatment period. Furthermore, the PDMS- b -PPeFPA system exhibited a remarkable etch contrast for O 2 reactive ion etching, yielding unidirectionally aligned air–inorganic nanoarrays emanating from the perpendicular lamellae between the electrodes. This study reports a system engineering approach for conceiving highly immiscible, silicon- and fluorine-containing BCP whose components exhibit identical surface tensions ( $$\gamma$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> PDMS ≈ $$\gamma$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> PPeFPA ) and for generating perpendicularly oriented lamellar microdomains due to substrate neutrality. Materials science ; Copolymer ; Lamellar structure ; Polymer ; Polydimethylsiloxane ; Polymer chemistry ; Composite material Block Copolymer Self-Assembly ; Liquid Crystal Research Advancements ; Fluid Dynamics and Thin Films
Authors: Marius Murariu | Yoann Paint | Oltea Murariu | Fouad Laoutid | Philippe Dúbois
Source: Polymers (article, 2023-02-05)
Field: Materials Science — Biomaterials

Engineering Polypropylene–Calcium Sulfate (Anhydrite II) Composites: The Key Role of Zinc Ionomers via Reactive Extrusion Polypropylene (PP) is one of the most versatile polymers widely used in packaging, textiles, automotive, and electrical applications. Melt blending of PP with micro- and/or nano-fillers is a common approach for obtaining specific end-use characteristics and major enhancements of properties. The study aims to develop high-performance composites by filling PP with CaSO<sub>4</sub> β-anhydrite II (AII) issued from natural gypsum. The effects of the addition of up to 40 wt.% AII into PP matrix have been deeply evaluated in terms of morphology, mechanical and thermal properties. The PP-AII composites (without any modifier) as produced with internal mixers showed enhanced thermal stability and stiffness. At high filler loadings (40% AII), there was a significant decrease in tensile strength and impact resistance; therefore, custom formulations with special reactive modifiers/compatibilizers (PP functionalized/grafted with maleic anhydride (PP-g-MA) and zinc diacrylate (ZnDA)) were developed. The study revealed that the addition of only 2% ZnDA (able to induce ionomeric character) leads to PP-AII composites characterized by improved kinetics of crystallization, remarkable thermal stability, and enhanced mechanical properties, i.e., high tensile strength, rigidity, and even rise in impact resistance. The formation of Zn ionomers and dynamic ionic crosslinks, finer dispersion of AII microparticles, and better compatibility within the polyolefinic matrix allow us to explain the recorded increase in properties. Interestingly, the PP-AII composites also exhibited significant improvements in the elastic behavior under dynamic mechanical stress and of the heat deflection temperature (HDT), thus paving the way for engineering applications. Larger experimental trials have been conducted to produce the most promising composite materials by reactive extrusion (REx) on twin-screw extruders, while evaluating their performances through various methods of analysis and processing. Materials science ; Polypropylene ; Composite material ; Ultimate tensile strength ; Thermal stability ; Extrusion ; Reactive extrusion ; Izod impact strength test ; Heat deflection temperature ; Chemical engineering biodegradable polymer synthesis and properties ; Polymer Nanocomposites and Properties ; Natural Fiber Reinforced Composites
Authors: Jan Meißner | L.H. Ahrens | Joachim Pasel | Alexander Schwedt | Sebastian Wohlrab | Joachim Mayer | Ralf Peters
Source: Scientific Reports (article, 2023-06-08)
Field: Materials Science — Materials Chemistry

An improved preparation method for a CuO/CeO2-coated monolith for the CO–PrOx reaction In this study, we present a method for directly coating monoliths with a CeO<sub>2</sub>/CuO catalyst using the urea-nitrate combustion method. The catalyst was characterized by means of XRD, SEM/EDX, and EPR measurements. Experimental results are described, when this catalyst was used for the preferential oxidation of CO. The catalytic activity for the CO-PrOx-reaction was measured by recording CO conversion as a function of the reaction temperature in a hydrogen-rich gas mixture in the presence and absence of water vapor. In a long-term test of over 310 h, the catalyst's long-term stability was demonstrated. Direct coating is shown to be a promising approach by which a larger amount of catalyst can be deposited onto the monolith in a single step than would be possible with washcoats. Monolith ; PROX ; Chemistry ; Chemical engineering ; Catalysis ; Organic chemistry ; Carbon monoxide Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Catalysts for Methane Reforming
Authors: Babita Rani | Vladimir Bubanja | V. K. Jindal
Source: Journal of Physics Condensed Matter (article, 2023-07-07)
Field: Materials Science — Materials Chemistry

Enhanced quantum capacitance of MX<sub>4</sub> (M = Fe, Co, Ni, Cu, and Zn; X = N, P) moieties embedded graphene: a DFT study In this work, density functional theory calculations are performed to study the impact of embedding transition metal-(N/P)<sub>4</sub>moieties in graphene on its geometric structure, electronic properties, and quantum capacitance. Enhancement of quantum capacitance of transition metal doped nitrogen/phosphorus pyridinic graphenes is observed, which is directly related to the availability of states near the Fermi level. The findings show that electronic properties and hence quantum capacitance of graphene can be tuned by varying transition metal dopants and/or their coordination environment. Modified graphenes can suitably be chosen as positive or negative electrodes of asymmetric supercapacitors depending upon the values of quantum capacitance and stored charges. Furthermore, quantum capacitance can be enhanced by widening the working voltage window. The results can serve as guidelines for the design of graphene-based electrodes in supercapacitor applications. Quantum capacitance ; Graphene ; Capacitance ; Supercapacitor ; Materials science ; Transition metal ; Dopant ; Density functional theory ; Condensed matter physics ; Fermi level ; Electrode ; Quantum ; Doping ; Nanotechnology ; Optoelectronics ; Chemistry ; Physics ; Quantum mechanics ; Computational chemistry ; Physical chemistry Graphene research and applications ; Supercapacitor Materials and Fabrication ; Advancements in Battery Materials
Authors: Arige Sumanth | Vikash Mishra | M. S. Ramachandra Rao | Tejendra Dixit
Source: physica status solidi (a) (article, 2023-07-21)
Field: Materials Science — Materials Chemistry

Interface Analysis of CuO/ZnO Heterojunction for Optoelectronic Applications: An Experimental and Simulation Study Material interfaces are essential building blocks for a wide variety of emerging technologies. Well‐defined and optimized heterostructures serve as the foundation for developing materials toward innovative optoelectronic applications. The distinctive features of heterojunctions have recently attracted the attention of the optoelectronics community, prompting a rise in the construction of modern devices. A solution‐based method is presented for developing a heterojunction made of copper oxide nanorods coated with zinc oxide thin films. Coating ZnO thin films on vertically oriented CuO nanorods results in the development of ZnO/CuO heterojunction configuration, which exhibits outstanding optoelectronic capabilities like broadband absorption and white light emission. Additionally, systematic ab initio computations have been done to comprehend the impact on various optical and electrical properties. It is observed that defects play a very crucial role in determining the quantum efficiency as well as improved visible to near‐infrared absorption. Moreover, the formation of energy levels near conduction bands in the presence of vacancies leads to broad absorption in the ultraviolet–visible region, and therefore, greater than 60% quantum efficiency over the range 350–800 nm is observed. Therefore, the presented work serves as the foundation for additional design and optimization techniques for oxide heterojunctions and emerging applications. Heterojunction ; Materials science ; Nanorod ; Optoelectronics ; Absorption (acoustics) ; Nanotechnology ; Ultraviolet ; Oxide ; Semiconductor ZnO doping and properties ; Copper-based nanomaterials and applications ; Gas Sensing Nanomaterials and Sensors
Authors: Philippe Lalanne | А. К. Дмитриев | Carsten Rockstuhl | Alexander Sprafke | Kévin Vynck
Source: arXiv (Cornell University) (preprint, 2023-10-22)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Minireview on Disordered Optical Metasurfaces The use of coherent wave phenomena to enhance device performance is a cornerstone of modern optics. In juxtaposition to (locally) periodic metasurfaces, their disordered counterparts exhibit an interplay of destructive and constructive interferences occurring at the same spatial and spectral frequencies. This attribute provides disordered metasurfaces with a remarkable degree of flexibility, setting them apart from the constraints of periodic arrangements. Hereafter, we provide a concise overview of the cutting-edge developments and offer insights into the forthcoming research in this dynamic field. Constructive ; Flexibility (engineering) ; Metamaterial ; Cornerstone ; Field (mathematics) ; Enhanced Data Rates for GSM Evolution ; Optics ; Computer science ; Physics ; Telecommunications ; Mathematics ; Process (computing) ; History Metamaterials and Metasurfaces Applications ; Photonic Crystals and Applications ; Plasmonic and Surface Plasmon Research
Authors: Chiara Borsari | Alexandra Ioana Corfu | Paola Conti
Source: CHIMIA International Journal for Chemistry (article, 2023-05-31)
Field: Chemistry — Organic Chemistry

Understanding Intrinsic Warhead Reactivity and Cysteine Druggability in Covalent Drug Discovery Druggability ; Warhead ; Drug discovery ; Cysteine ; Chemistry ; Reactivity (psychology) ; Covalent bond ; Computational biology ; Combinatorial chemistry ; Biochemistry ; Physics ; Biology ; Medicine ; Organic chemistry ; Enzyme ; Gene Click Chemistry and Applications ; Computational Drug Discovery Methods ; Organic Chemistry Cycloaddition Reactions
Authors: Jonas Braun | Daniel Seufert | Christopher E. Anson | Jinkui Tang | Annie K. Powell
Source: International Journal of Molecular Sciences (article, 2023-12-23)
Field: Materials Science — Electronic, Optical and Magnetic Materials

An Effectively Uncoupled Gd8 Cluster Formed through Fixation of Atmospheric CO2 Showing Excellent Magnetocaloric Properties The [Gd<sub>8</sub>(opch)<sub>8</sub>(CO<sub>3</sub>)<sub>4</sub>(H<sub>2</sub>O)<sub>8</sub>]·4H<sub>2</sub>O·10MeCN coordination cluster (<b>1</b>) crystallises in P1¯. The Gd<sub>8</sub> core is held together by four bridging carbonates derived from atmospheric CO<sub>2</sub> as well as the carboxyhydrazonyl oxygens of the 2-hydroxy-3-methoxybenzylidenepyrazine-2-carbohydrazide (H<sub>2</sub>opch) Schiff base ligands. The magnetic measurements show that the Gd<sup>III</sup> ions are effectively uncoupled as seen from the low Weiss constant of 0.05 K needed to fit the inverse susceptibility to the Curie-Weiss law. Furthermore, the magnetisation data are consistent with the Brillouin function for eight independent Gd<sup>III</sup> ions. These features lead to a magnetocaloric effect with a high efficiency which is 89% of the theoretical maximum value. Magnetic refrigeration ; Carbohydrazide ; Chemistry ; Ion ; Schiff base ; Cluster (spacecraft) ; Crystallography ; Magnetization ; Physics ; Magnetic field ; Medicinal chemistry Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes ; Inorganic Chemistry and Materials
Authors: Yury V. Ryabchikov | Alexander N. Zaderko
Source: Photonics (article, 2023-11-03)
Field: Materials Science — Materials Chemistry

“Green” Fluorescent–Plasmonic Carbon-Based Nanocomposites with Controlled Performance for Mild Laser Hyperthermia Fluorescent carbon nanodots are a promising nanomaterial for different applications in biophotonics, sensing and optical nanothermometry fields due to their strong fluorescence properties. However, their multi-modal applications are considerably limited, requiring the use of several nanoagents that could solve different tasks simultaneously. In this paper, we report the first experimental results on a facile “green” laser-based synthesis of multi-modal carbon–metallic nanocomposites with tuned optical performance. This simple approach leads to the appearance of finely controlled plasmonic properties in carbon-based nanocomposites whose spectral position is adapted by using an appropriate material. Thus, longer laser ablation provokes 29-fold increase in the absorption intensity of carbon–gold nanocomposites due to the increase in the metal content from 13% (30 s) to 53% (600 s). Despite strong plasmonic properties, the metal presence results in the quenching of the carbon nanostructures’ fluorescence (2.4-fold for C-Au NCs and 3.6-fold for C-Ag NCs for 600 s ablation time). Plasmonic nanocomposites with variable metal content reveal a ~3-fold increase in the laser-to-heat conversion efficiency of carbon nanodots matching the temperature range for mild hyperthermia applications. The findings presented demonstrate a facile approach to expanding the properties of chemically prepared semiconductor nanostructures due to the formation of novel semiconductor–metallic nanocomposites using a “green” approach. Together with the ease in control of their performance, it can considerably increase the impact of semiconductor nanomaterials in various photonic, plasmonic and biomedical applications. Materials science ; Nanocomposite ; Plasmon ; Nanomaterials ; Lasing threshold ; Laser ; Carbon fibers ; Photonics ; Nanodot ; Nanotechnology ; Semiconductor ; Optoelectronics ; Laser ablation ; Optics ; Composite material Carbon and Quantum Dots Applications ; Laser-Ablation Synthesis of Nanoparticles ; Graphene and Nanomaterials Applications