jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: S. Tazekritt | M. Gallouze | A. Kellou
Source: Journal of Applied Physics (article, 2024-03-01)
Field: Materials Science — Materials Chemistry

DFT study of energetics and optoelectronics properties of B, C, and N binary and ternary honeycomb structures Using the Full Potential Linear Augmented Plane Wave and the pseudo-potential method based on the Density Functional Theory, we investigate the physical properties of two-dimensional (2D) boron nitride, carbon nitride, and boron carbide as well as their ternary system boron carbon nitride (BCN). The structural and optoelectronic properties are determined and discussed in detail with available theoretical and experimental results. We show that the studied physical properties are influenced and tunable by atom concentration. A high concentration of nitrogen (&amp;gt; 50%) disturbs the honeycomb structure of binary and ternary alloys. Additionally, the optoelectronic properties are very sensitive to the amount of boron and nitrogen atoms. The zero bandgap is only conserved for B3C12N3 and B6C6N6 ternary systems. A large bandgap was observed for B9N9 (∼3.9 eV) and a moderate one for B6N12 and B3N15 (∼2 eV). The coexistence of boron, carbon, and nitrogen atoms with different concentrations has important optical properties as they can absorb light in all spectra. However, they have more active absorption in the ultraviolet than visible regions. It is more interesting to use ternary BCN than binary or pristine alloys with tunable optoelectric properties, by varying the nitrogen content in nanodevices. Ternary operation ; Materials science ; Band gap ; Density functional theory ; Nitride ; Boron ; Boron nitride ; Absorption (acoustics) ; Carbon fibers ; Boron carbide ; Nitrogen ; Absorption spectroscopy ; Optoelectronics ; Nanotechnology ; Chemistry ; Computational chemistry ; Metallurgy ; Composite material ; Optics ; Organic chemistry ; Layer (electronics) Graphene research and applications ; Boron and Carbon Nanomaterials Research ; MXene and MAX Phase Materials
Authors: Collin D. Wick | Andrew J. Peters | Guoqiang Li
Source: Journal of Polymer Science (article, 2024-10-04)
Field: Materials Science — Polymers and Plastics

A Molecular Dynamics Modeling Framework for Shape Memory Vitrimers ABSTRACT Vitrimers with self‐healing, recycling, and remolding capabilities are changing the paradigm for thermoset polymer design. In the past several years, vitrimers that exhibit shape memory effects and are curable by ultraviolet (UV) light have made significant progress in the realm of 4D printing. Herein, we report a molecular dynamics (MD) modeling framework to model UV curable shape memory vitrimers. We used our framework and compared our modeling results with one UV curable shape memory vitrimer found in the literature, bisphenol A glycerolate dimethacrylate. The comparison showed reasonable agreement between the modeling and experimental results in terms of thermomechanical and shape memory properties, along with self‐healing efficiency. It was found that during recycling, it was important for the network to percolate through a majority of the system to get reasonably high recovery stress and recycling efficiency. Once this was achieved, a topological descriptor that was found to represent the compactness of the network was identified as having a very high correlation with recovery stress and recycling efficiency for networks that percolated 70% or more of the monomers in a system. Molecular dynamics ; Statistical physics ; Dynamics (music) ; Computer science ; Biological system ; Physics ; Computational chemistry ; Chemistry ; Biology ; Acoustics Polymer composites and self-healing ; Photochromic and Fluorescence Chemistry ; Advanced Polymer Synthesis and Characterization
Authors: Hanrui Su | Yun Hang Hu
Source: Proceedings of the National Academy of Sciences (article, 2024-01-02)
Field: Materials Science — Materials Chemistry

Thermo-photo catalytic anode process for carbonate-superstructured solid fuel cells Converting hydrocarbons and greenhouse gases (i.e., carbon dioxide, CO<sub>2</sub>) directly into electricity through fuel cells at intermediate temperatures (450 to 550 °C) remains a significant challenge, primarily due to the sluggish activation of C-H and C=O bonds. Here, we demonstrated a unique strategy to address this issue, in which light illumination was introduced into the thermal catalytic CO<sub>2</sub> reforming of ethane in the anode as a unique thermo-photo anode process for carbonate-superstructured solid fuel cells. The light-enhanced fuel activation led to excellent cell performance with a record-high peak power density of 168 mW cm<sup>-2</sup> at an intermediate temperature of 550 °C. Furthermore, no degradation was observed during ~50 h operation. Such a successful integration of photo energy into the fuel cell system provides a new direction for the development of efficient fuel cells. Anode ; Materials science ; Catalysis ; Chemical engineering ; Power density ; Fuel cells ; Chemical energy ; Degradation (telecommunications) ; Chemistry ; Electrode ; Power (physics) ; Organic chemistry ; Electrical engineering ; Physical chemistry Advancements in Solid Oxide Fuel Cells ; Fuel Cells and Related Materials ; Catalysis and Oxidation Reactions
Authors: Afifeh Khorramshokouh | Hesam Ramezani | Mehdi Sahami | Mehdi Sharif | Behzad Vaferi
Source: International Journal of Polymer Science (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Silver Nanoparticles Decorated in In Situ Reduced Graphene Oxide Nanohybrids Improved Properties in Poly(vinylidene fluoride)/Poly(methyl methacrylate) Blends In this paper, reduced graphene oxide decorated with silver nanoparticle (rGO‐Ag) nanohybrids were prepared using an environmentally friendly approach and incorporated as reinforcement in poly(vinylidene fluoride)‐poly(methyl methacrylate) blends via a melt mixing process. The microstructure of rGO‐Ag nanohybrids and its effect on the microstructure, mechanical, thermal, and electrical properties of the PVDF/PMM/rGO‐Ag was studied using Fourier transform infrared (FTIR), Raman spectroscopy, X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), tensile, thermogravimetric analysis (TGA), and impedance spectroscopy methods. FTIR and TEM analysis confirmed that rGO‐Ag successfully synthesized and Ag nanoparticles are located on the rGO surface. The tensile analysis demonstrated that incorporating 1 wt.% of rGO‐Ag in PVDF/PMMA blend increases Young’s modulus and strength of nanocomposite up to 31% and 35%, respectively. The Halpin‐Tsai model was also used for PVDF/PMMA/rGO‐Ag nanocomposites, and the results confirmed that this model works well to predict the tensile modulus. Impedance spectroscopy analysis showed that the presence of rGO‐Ag nanohybrids in PVDF/PMMA blend effectively enhanced the conductivity of PVDF/PMMA blend. TGA results demonstrated that the presence of rGO‐Ag nanohybrids enhanced the thermal stability of nanocomposites and increased the degradation temperature of PVDF/PMMA/rGO‐Ag nanocomposites in the range of 20°C compared to PVDF/PMMA blend. Materials science ; Graphene ; Poly(methyl methacrylate) ; Fluoride ; In situ ; Methyl methacrylate ; Oxide ; Nanoparticle ; Methacrylate ; Chemical engineering ; Polymer chemistry ; Composite material ; Polymer ; Nanotechnology ; Copolymer ; Organic chemistry ; Inorganic chemistry ; Chemistry Graphene research and applications ; Polymer Nanocomposite Synthesis and Irradiation ; Graphene and Nanomaterials Applications
Authors: Jianqi Xi | Hongliang Zhang | Ranran Su | Shuguang Wei | Xuanxin Hu | Benoît Queylat | Tae‐Ho Kim | Adrien Couet | Izabela Szlufarska
Source: npj Materials Degradation (article, 2024-02-01)
Field: Materials Science — Ceramics and Composites

Coupling of radiation and grain boundary corrosion in SiC Abstract Radiation and corrosion can be coupled to each other in non-trivial ways and such coupling is of critical importance for the performance of materials in extreme environments. However, it has been rarely studied in ceramics and therefore it is not well understood to what extent these two phenomena are coupled and by what mechanisms. Here, we discover that radiation-induced chemical changes at grain boundaries of ceramics can have a significant (and positive) impact on the corrosion resistance of these materials. Specifically, we demonstrate using a combination of experimental and simulation studies that segregation of C to grain boundaries of silicon carbide leads to improved corrosion resistance. Our results imply that tunning of stoichiometry at grain boundaries either through the sample preparation process or via radiation-induced segregation can provide an effective method for suppressing surface corrosion. Corrosion ; Grain boundary ; Silicon carbide ; Materials science ; Ceramic ; Coupling (piping) ; Carbide ; Stoichiometry ; Metallurgy ; Radiation ; Radiation damage ; Radiation resistance ; Microstructure ; Optics ; Physical chemistry ; Chemistry ; Physics Advanced ceramic materials synthesis ; Nuclear materials and radiation effects ; Fusion materials and technologies
Authors: Tarun Maity | Anandu K. Balachandran | Lakshmi Priya Krishnamurthy | Karthik L. Nagar | Raghavender S. Upadhyayula | Shubhashis Sengupta | Prabal K. Maiti
Source: ACS Omega (article, 2024-05-27)
Field: Materials Science — Polymers and Plastics

Data-Driven Approaches to Predict Dendrimer Cytotoxicity Dendrimers are employed as functional elements in contrast agents and are proposed as nontoxic vehicles for drug delivery. Toxicity is a property that is to be evaluated for this novel class of bionanomaterials for in vivo applications. The current research is hampered due to the lack of structured data sets for toxicity studies for dendrimers. In this work, we have built a data set by curating literature for toxicity data and augmented it with structural and physicochemical features. We present a comprehensive, feature-rich database of dendrimer toxicity measured across various cell lines for prediction, design, and optimization studies. We have also explored novel computational approaches for predicting dendrimer cytotoxicity. We demonstrate superior outcomes for toxicity prediction using essential regression in the space of small data sets. Dendrimer ; Cytotoxicity ; Chemistry ; Computer science ; Biochemistry ; In vitro Dendrimers and Hyperbranched Polymers ; Computational Drug Discovery Methods ; Chemical Synthesis and Analysis
Authors: Christopher B. Larsen | Kathryn Ledbetter | Daniel R. Nascimento | Elisa Biasin | Muhammad Qureshi | S. Nowak | Dimosthenis Sokaras | Niranjan Govind | Amy A. Cordones
Source: Journal of the American Chemical Society (article, 2024-10-08)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Metal–Ligand Covalency in the Valence Excited States of Metal Dithiolenes Revealed by S 1s3p Resonant Inelastic X-ray Scattering Metallo dithiolene complexes with biological and catalytic relevance are well-known for having strong metal-ligand covalency, which dictates their valence electronic structures. We present the resonant sulfur Kβ (1s3p) X-ray emission spectroscopy (XES) for a series of Ni and Cu bis(dithiolene) complexes to reveal the ligand sulfur contributions to both the occupied and unoccupied valence orbitals. While S K-edge X-ray absorption spectroscopy played a critical role in identifying the covalency of the unoccupied orbitals of metal dithiolenes, the present focus on XES explores the occupied density of states. For a series of [Cu(mnt)<sub>2</sub>]<sup><i>n</i>-</sup> and [Ni(mnt)<sub>2</sub>]<sup><i>n</i>-</sup> anions and dianions, a comparison of the nonresonant and resonant S Kβ XES spectra highlights the dramatic improvement in spectral resolution and corresponding ability to differentiate subtle changes in occupied electronic structure across the series. Furthermore, the use of resonant inelastic X-ray scattering (RIXS) probes the valence excited states and the core-valence couplings of the complexes. By employing a theoretical approach based on time-dependent density functional theory to interpret the RIXS spectra, we reveal how metal-ligand covalency influences the excited state energies and covalencies. We identify the low energy excited states as having the same symmetry as the nominal "ligand field" or "d-d" states that typically dominate the photophysics of 3d metal complexes but with significant metal-ligand charge transfer character dictated by their covalency. These results suggest that strong metal-ligand covalency can be used to influence the charge-transfer photochemistry of first row transition metal complexes. Chemistry ; Valence (chemistry) ; Atomic orbital ; Metal ; Excited state ; Resonant inelastic X-ray scattering ; Crystallography ; Electronic structure ; Spectroscopy ; Density functional theory ; Molecular orbital ; Ligand (biochemistry) ; Scattering ; Atomic physics ; Inelastic scattering ; Molecule ; Computational chemistry ; Inelastic neutron scattering ; Physics ; Electron Organic and Molecular Conductors Research ; Machine Learning in Materials Science ; Advanced Chemical Physics Studies
Authors: Zhuozheng Wang | Wenbo Xie | Yarong Xu | Yulan Han | Jiayan Xu | P. Hu
Source: Catalysis Science & Technology (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Comprehensive understanding of ethylene epoxidation on copper catalysts: a microkinetic study with coverage effects Ethylene epoxidation is one of the fundamental industrial reactions, garnering extensive theoretical and experimental studies. Ethylene ; Catalysis ; Copper ; Chemistry ; Organic chemistry Catalytic Processes in Materials Science ; Electrocatalysts for Energy Conversion ; Catalysis and Oxidation Reactions
Authors: Md. Imrul Khalid | Mohamed S. H. Salem | Shinobu Takizawa
Source: Molecules (review, 2024-01-05)
Field: Chemistry — Organic Chemistry

Synthesis and Structural and Optical Behavior of Dehydrohelicene-Containing Polycyclic Compounds Dehydrohelicene-based molecules stand out as highly promising scaffolds and captivating chiroptical materials, characterized by their unique chirality. Their quasi-helical π-conjugated molecular architecture, featuring successively <i>ortho</i>-annulated aromatic rings, endows them with remarkable thermal stability and optical properties. Over the past decade, diverse approaches have emerged for synthesizing these scaffolds, reinvigorating this field, with anticipated increased attention in the coming years. This review provides a comprehensive overview of the historical evolution of dehydrohelicene chemistry since the pioneering work of Zander and Franke in 1969 and highlights recent advancements in the synthesis of various molecules incorporating dehydrohelicene motifs. We elucidate the intriguing structural features and optical merits of these molecules, occasionally drawing comparisons with their helicene or circulene analogs to underscore the significance of the bond between the helical termini. Helicene ; Chirality (physics) ; Molecule ; Conjugated system ; Nanotechnology ; Chemistry ; Materials science ; Polymer ; Physics ; Organic chemistry ; Chiral symmetry Synthesis and Properties of Aromatic Compounds ; Porphyrin and Phthalocyanine Chemistry ; Photochromic and Fluorescence Chemistry
Authors: Susana Devesa | Carlos O. Amorim | J.H. Belo | João P. Araújo | S. Soreto Teixeira | M.P.F. Graça | L. C. Costa
Source: Magnetochemistry (article, 2024-10-20)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Comprehensive Characterization of Bi1.34Fe0.66Nb1.34O6.35 Ceramics: Structural, Morphological, Electrical, and Magnetic Properties Recent research in solid-state physics and materials engineering focuses on the development of new dielectric materials, with bismuth-based pyrochlores being already extensively applied in communications technology for their excellent dielectric properties and relatively low sintering temperatures. Herein, the structural, morphological, electrical, and magnetic properties of Bi1.34Fe0.66Nb1.34O6.35 ceramic, prepared by the sol–gel method and sintered at 500 °C, are investigated. The Rietveld refinement of the XRD pattern showed a cubic phase belonging to the space group Fd-3m and a crystallite size of 42 nm. Transmission electron microscopy further confirmed the crystallite size and the homogeneous distribution of Bi, Fe, Nb, and O elements, as evidenced by high-angle annular dark field imaging and STEM-EDX mapping. The morphology of the sample, assessed by scanning electron microscopy, is characterized by submicron-sized spherical particles. Dielectric spectroscopic studies revealed that the dielectric properties, strongly influenced by frequency and temperature, indicate the material’s potential for energy storage due to lower dielectric loss compared to the dielectric constant. The observed relaxation phenomena, confirmed through variations in dielectric loss and loss tangent, highlight the influence of grain boundaries and temperature on electron hopping and charge carrier dynamics. Using SQUID magnetometry, we identified two distinct magnetic phases. The primary phase, corresponding to the Bi1.34Fe0.66Nb1.34O6.35 ceramic, exhibits an antiferromagnetic behavior below its Néel temperature at around 8.8 K. A secondary high-Curie temperature ferrimagnetic phase, likely vestigial maghemite and/or magnetite, was also detected, indicating an estimated fraction below 0.02 wt.%. Characterization (materials science) ; Ceramic ; Materials science ; Magnetic susceptibility ; Condensed matter physics ; Nanotechnology ; Nuclear magnetic resonance ; Metallurgy ; Physics Multiferroics and related materials ; Ferroelectric and Piezoelectric Materials ; Nuclear materials and radiation effects
Authors: Maddalen Puyadena | Erika Pajares | Loli Martin | Aitor Barrio | Alba González | Lourdes Irusta
Source: Progress in Organic Coatings (article, 2024-01-15)
Field: Materials Science — Polymers and Plastics

UV-curable acrylic end-capped amphoteric waterborne polyurethane coatings Waterborne polyurethane dispersions (WPUs) are environmentally friendly coatings since they present low amount of volatile organic compound amounts (VOCs). In the majority of the WPUs the dispersions are balanced with anionic groups and accordingly their stability at low pH is limited. In order to this drawback to be solved, in this work a tertiary amine containing chain extender (triethanolamine, TEOA) was introduced together with a conventional internal emulsifier (carboxylic acid) in acrylic end-capped polyurethane dispersions giving rise to amphoteric UV curable WPUs. After adding a radical photo-initiator and film formation, the coatings were cured under UV irradiation. The properties of amphoteric and anionic dispersions were compared. The best properties were obtained for the samples containing a 1/1 amine/acid molar ratio. Thus, while the anionic dispersions coagulated at low pH values, the 1/1 amphoteric dispersion showed high stability to pH changes. After curing this sample with UV irradiation, the gel content of the film was higher and the water vapour transmission rate was lower than that of the anionic polyurethane because of the strong acid/base interaction. The results showed that the amphoteric WPUs are promising for various applications, offering stability over a wider pH range than traditional formulations. Triethanolamine ; Polyurethane ; Materials science ; UV curing ; Amine gas treating ; Acrylic acid ; Polymer chemistry ; Chemical engineering ; Curing (chemistry) ; Prepolymer ; Nuclear chemistry ; Organic chemistry ; Composite material ; Copolymer ; Chemistry ; Polymer Polymer composites and self-healing ; Advanced Polymer Synthesis and Characterization ; Silicone and Siloxane Chemistry
Authors: Klara Bonneau | Jonas Lederer | Clark Templeton | David Rosenberger | Klaus‐Robert Müller | Cecilia Clementi
Source: arXiv (Cornell University) (preprint, 2024-07-05)
Field: Materials Science — Materials Chemistry

Peering inside the black box: Learning the relevance of many-body functions in Neural Network potentials Machine learned potentials are becoming a popular tool to define an effective energy model for complex systems, either incorporating electronic structure effects at the atomistic resolution, or effectively renormalizing part of the atomistic degrees of freedom at a coarse-grained resolution. One of the main criticisms to machine learned potentials is that the energy inferred by the network is not as interpretable as in more traditional approaches where a simpler functional form is used. Here we address this problem by extending tools recently proposed in the nascent field of Explainable Artificial Intelligence (XAI) to coarse-grained potentials based on graph neural networks (GNN). We demonstrate the approach on three different coarse-grained systems including two fluids (methane and water) and the protein NTL9. On these examples, we show that the neural network potentials can be in practice decomposed in relevance contributions to different orders, that can be directly interpreted and provide physical insights on the systems of interest. Peering ; Black box ; Relevance (law) ; Artificial neural network ; Computer science ; Artificial intelligence ; The Internet ; World Wide Web ; Political science Machine Learning in Materials Science ; Quantum many-body systems
Authors: Kedarnath Chaudhary | Vikrant K. Haribhakta
Source: MethodsX (review, 2024-09-23)
Field: Materials Science — Materials Chemistry

Micro-drilling on shape memory alloys—A review Technology like micro-hole drilling has progressed because of the machining industry's demand for high-precision micro components. Although micro drilling can be duplicated in theory, many challenges must be overcome before this becomes a reality. Micro-drilling with a thermal-mechanical interaction in the alloy is simulated in Abaqus. It looks at twist-bit modeling, material constitutive modeling, chip separation criteria, and element division. Focusing on work and tool electrode materials, hole specifications, micro hole types (through or blind holes), process parameters, performance measurements, and significant discoveries, this study presents a complete survey of the literature on spark methods for drilling microscopic holes. With an emphasis on spark erosion machining, drilling, and its modifications, this study seeks to aid researchers and academics by showcasing the potential of these methods to create extremely small holes. Microdrilling is critical for manufacturing miniaturized Nitinol components having applications in the medical field, robotics industry. Mechanical microdrilling offers a cost-effective and precise method over non-conventional ones. Thus, the model may identify the drilling performance's key process parameters. They can also help operators choose micro-drilling-optimal machining parameters. Modeling micro-drilling software helps in shaping an alloy. Drilling ; Shape-memory alloy ; Materials science ; Petroleum engineering ; Computer science ; Nanotechnology ; Biochemical engineering ; Geology ; Engineering ; Metallurgy Shape Memory Alloy Transformations ; Advanced machining processes and optimization