jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Siddarth K. Achar | Julian Schneider | Derek A. Stewart
Source: ACS Applied Materials & Interfaces (article, 2022-12-14)
Field: Materials Science — Materials Chemistry

Using Machine Learning Potentials to Explore Interdiffusion at Metal–Chalcogenide Interfaces Chalcogenide alloys are key materials for selector and memory elements used in next-generation nonvolatile memory cells. However, the high electric fields and Joule heating experienced during operation can promote interdiffusion at the interfaces that degrade device performance over time. A clear atomic scale understanding of how chalcogenide alloys interact with electrodes could aid in identifying ways to improve long-term device endurance. In this work, we develop a robust set of moment tensor potentials (MTPs) to examine interactions between Ge-Se alloys and Ti electrodes. Previous works have shown evidence of strong interactions between Ti and chalcogenide alloys. This system offers an important first test in the use of ML empirical potentials to understand the role of interfaces in endurance in memory elements and broader nanoscale devices. The empirical potentials are constructed using an active learning moment tensor potential framework that leverages a broad data set of first-principles calculations for Ti, Ge, and Se compounds. Long-term simulations (>1 ns) show significant interdiffusion at the Ti|Ge-Se interface with Ti and Se both actively moving across the original interface. The strong chemical affinity of Ti and Se leads to a well-defined Ti-Se region and a severely Se-depleted central Ge-Se region with unfavorable selector characteristics. The evolution of the Ti-Se layer can be described using a self-limited growth model. By comparing effective Ti-Se diffusion constants for simulations at different temperatures, we find a low activation energy of 0.1 eV for Ti-Se layer interdiffusion. Chalcogenide ; Materials science ; Diffusion ; Optoelectronics ; Electrode ; Layer (electronics) ; Engineering physics ; Nanotechnology ; Thermodynamics ; Physical chemistry Machine Learning in Materials Science ; Advanced Memory and Neural Computing ; Phase-change materials and chalcogenides
Authors: Giovanni Angiulli | Mario Versaci
Source: Applied Sciences (article, 2022-11-02)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Extraction of the Electromagnetic Parameters of a Metamaterial Using the Nicolson–Ross–Weir Method: An Analysis Based on Global Analytic Functions and Riemann Surfaces The characterization of electromagnetic metamaterials (MMs) plays a fundamental role in their engineering processes. To this end, the Nicolson–Ross–Weir (NRW) method is intensively used to recover the effective parameters of MMs, even though this is affected by the branch ambiguity problem. In this paper, we face this issue in the context of global analytic functions and Riemann surfaces. This point of view allows us to rigorously demonstrate the mathematical foundations of an algorithmic approach for avoiding the branch ambiguity problem, in which the phase unwrapping method is merged with K-K relations for recovering the effective parameters of an MM. In addition, exploiting the intimate relationship between the K-K relations and the Hilbert transform, a simple variant of the above algorithm is presented. Riemann hypothesis ; Mathematics ; Ambiguity ; Context (archaeology) ; Point (geometry) ; Applied mathematics ; Mathematical analysis ; Computer science ; Algorithm ; Geometry ; Geology Metamaterials and Metasurfaces Applications ; Advanced Antenna and Metasurface Technologies ; Electromagnetic Scattering and Analysis
Authors: Keda Li | Jinghong Ding | Yuxiong Guo | Hongchao Wu | Wenwen Wang | Jiaqi Ji | Qi Pei | Chenliang Gong | Zhongying Ji | Xiaolong Wang
Source: Polymers (article, 2022-06-30)
Field: Materials Science — Polymers and Plastics

Direct Ink Writing of Phenylethynyl End-Capped Oligoimide/SiO2 to Additively Manufacture High-Performance Thermosetting Polyimide Composites The three-dimensional (3D) printing of a SiO<sub>2</sub>-filled thermosetting polyimide (SiO<sub>2</sub>@TSPI) composite with outstanding performance is realized via the direct ink writing (DIW) of polyamide acid (PAA) composite ink and thermal treatment conducted thereafter. The composite ink consists of phenylethynyl-terminated PAA and silica nanoparticles, where the SiO<sub>2</sub> nanoparticles serve as the rheology modifier that is necessary for the DIW technique to obtain self-supporting feedstock during 3D printing and the reinforcement filler that is used to enhance the performance of the final composite. As a result, printed parts with complex geometry and robust thermal stability are obtained. Due to the extrusion-based DIW technique, the printed structures exhibit anisotropic mechanical strength that highly depends on printing roads. This simple and convenient means of realizing 3D structures of thermosetting polyimides is a promising strategy in aerospace and other fields. Thermosetting polymer ; Materials science ; Composite number ; Polyimide ; Composite material ; Inkwell ; Extrusion ; Polyamide ; Thermal stability ; 3D printing ; Filler (materials) ; Rheology ; Nanoparticle ; Nanotechnology ; Chemical engineering ; Layer (electronics) Synthesis and properties of polymers ; Additive Manufacturing and 3D Printing Technologies ; Polymer composites and self-healing
Authors: Yang Yang | Kaijuan Li | Yaxin Wang | Zhanpeng Wu | Thomas P. Russell | Shaowei Shi
Source: Nanomaterials (review, 2022-10-27)
Field: Materials Science — Materials Chemistry

MXene-Based Porous Monoliths In the past decade, a thriving family of 2D nanomaterials, transition-metal carbides/nitrides (MXenes), have garnered tremendous interest due to its intriguing physical/chemical properties, structural features, and versatile functionality. Integrating these 2D nanosheets into 3D monoliths offers an exciting and powerful platform for translating their fundamental advantages into practical applications. Introducing internal pores, such as isotropic pores and aligned channels, within the monoliths can not only address the restacking of MXenes, but also afford a series of novel and, in some cases, unique structural merits to advance the utility of the MXene-based materials. Here, a brief overview of the development of MXene-based porous monoliths, in terms of the types of microstructures, is provided, focusing on the pore design and how the porous microstructure affects the application performance. MXenes ; Nanotechnology ; Materials science ; Porosity ; Microstructure ; Nanomaterials ; Porous medium ; Thriving ; Composite material MXene and MAX Phase Materials ; Graphene research and applications ; Graphene and Nanomaterials Applications
Authors: Lukas Lohmeyer | Elisabeth Kaifer | Hans‐Jörg Himmel
Source: Inorganic Chemistry (article, 2022-05-25)
Field: Chemistry — Inorganic Chemistry

Solvent-Induced Redox Isomerism of Cobalt Complexes with Redox-Active Bisguanidine Ligands Redox-isomeric coordination compounds, in which the magnetic and optical properties could be varied by a stimulated intramolecular electron transfer between the metal and a redox-active ligand, are of interest for several applications in catalysis and materials science. In this work, the redox chemistry of cobalt complexes with redox-active bisguanidine ligands is studied; systematic modifications at the redox-active bisguanidine and the co-ligand units allow for fine-tuning of the electronic structure, which eventually leads to the first observation of redox isomerism for cobalt complexes with redox-active guanidine ligands. Redox isomerism is triggered by a change in the solvent properties. Chemistry ; Redox ; Non-innocent ligand ; Cobalt ; Ligand (biochemistry) ; Intramolecular force ; Electron transfer ; Solvent ; Photochemistry ; Half-reaction ; Inorganic chemistry ; Combinatorial chemistry ; Stereochemistry ; Organic chemistry Metal-Catalyzed Oxygenation Mechanisms ; Metal complexes synthesis and properties ; Porphyrin and Phthalocyanine Chemistry
Authors: Juan Wu | Runping Ye | Dong-Jie Xu | Lingzhong Wan | Tomás Ramı́rez Reina | Hui Sun | Ying Ni | Zhangfeng Zhou | Xiaonan Deng
Source: Frontiers in Chemistry (review, 2022-08-05)
Field: Materials Science — Materials Chemistry

Emerging natural and tailored perovskite-type mixed oxides–based catalysts for CO2 conversions The rapid economic and societal development have led to unprecedented energy demand and consumption resulting in the harmful emission of pollutants. Hence, the conversion of greenhouse gases into valuable chemicals and fuels has become an urgent challenge for the scientific community. In recent decades, perovskite-type mixed oxide-based catalysts have attracted significant attention as efficient CO<sub>2</sub> conversion catalysts due to the characteristics of both reversible oxygen storage capacity and stable structure compared to traditional oxide-supported catalysts. In this review, we hand over a comprehensive overview of the research for CO<sub>2</sub> conversion by these emerging perovskite-type mixed oxide-based catalysts. Three main CO<sub>2</sub> conversions, namely reverse water gas shift reaction, CO<sub>2</sub> methanation, and CO<sub>2</sub> reforming of methane have been introduced over perovskite-type mixed oxide-based catalysts and their reaction mechanisms. Different approaches for promoting activity and resisting carbon deposition have also been discussed, involving increased oxygen vacancies, enhanced dispersion of active metal, and fine-tuning strong metal-support interactions. Finally, the current challenges are mooted, and we have proposed future research prospects in this field to inspire more sensational breakthroughs in the material and environment fields. Catalysis ; Perovskite (structure) ; Methanation ; Oxide ; Methane ; Materials science ; Greenhouse gas ; Mixed oxide ; Nanotechnology ; Chemical engineering ; Carbon fibers ; Chemistry ; Metallurgy ; Organic chemistry ; Engineering Catalytic Processes in Materials Science ; Catalysts for Methane Reforming ; Catalysis and Oxidation Reactions
Authors: Chen Wang | Fuwei Sun | Guokang He | Hongwei Zhao | Li Tian | Yibo Cheng | Guangtao Li
Source: Current Opinion in Colloid & Interface Science (article, 2022-11-14)
Field: Chemistry — Organic Chemistry

Noble metal nanoparticles meet molecular cages: A tale of integration and synergy Nanoparticle ; Noble metal ; Nanotechnology ; Metal ; Chemistry ; Materials science ; Organic chemistry Supramolecular Chemistry and Complexes ; Supramolecular Self-Assembly in Materials ; Advanced biosensing and bioanalysis techniques
Authors: Sandy M. Wong | Cheng Cao | Martina Lessio | Martina H. Stenzel
Source: Nanoscale (article, 2022-01-01)
Field: Materials Science — Polymers and Plastics

Sugar-induced self-assembly of curcumin-based polydopamine nanocapsules with high loading capacity for dual drug delivery Many drug delivery carriers reported in the literature require multistep assembly or often have very low drug loading capacities. Here, we present a simple sugar-based strategy that feeds the increased interest in high-loading nanomedicine. The driving force of the supramolecular nanocapsule formation is the interaction between curcumin (CCM) and the monosaccharide fructose. Drug and sugar are simply mixed in an aqueous solution in an open vessel, followed by coating the nanocapsules with polydopamine (PDA) to maintain structural integrity. We show that nanocapsules can still be obtained when other drugs are added, producing dual-drug nanoparticles with sizes of around 150-200 nm and drug loading contents of around 90% depending on the thickness of the PDA shell. This concept is widely applicable for a broad variety of drugs, as long as the drug has similar polarities to CCM. The key to success is the interaction of CCM and the second drug as shown in computational studies. The drug was able to be released from the nanocapsule at a release rate that could be fine-tuned by adjusting the thickness of the PDA layer. Nanocapsules ; Drug delivery ; Drug ; Nanomedicine ; Curcumin ; Nanotechnology ; Materials science ; Nanoparticle ; Aqueous solution ; Chemistry ; Pharmacology ; Organic chemistry ; Biochemistry Dendrimers and Hyperbranched Polymers ; Nanoparticle-Based Drug Delivery ; Advanced Drug Delivery Systems
Authors: Yu Zhou | Ping Wu | Fanshu Cao | Lei Shi | Ni Zhang | Zuqian Xue | Gen Luo
Source: RSC Advances (article, 2022-01-01)
Field: Chemistry — Organic Chemistry

Mechanistic insights into rare-earth-catalysed C–H alkylation of sulfides: sulfide facilitating alkene insertion and beyond The catalytic C-H alkylation with alkenes is of much interest and importance, as it offers a 100% atom efficient route for C-C bond construction. In the past decade, great progress in rare-earth catalysed C-H alkylation of various heteroatom-containing substrates with alkenes has been made. However, whether or how a heteroatom-containing substrate would influence the coordination or insertion of an alkene at the catalyst metal center remained elusive. In this work, the mechanism of Sc-catalysed C-H alkylation of sulfides with alkenes and dienes has been carefully examined by DFT calculations, which revealed that the alkene insertion could proceed <i>via</i> a sulfide-facilitated mechanism. It has been found that a similar mechanism may also work for the C-H alkylation of other heteroatom-containing substrates such as pyridine and anisole. Moreover, the substrate-facilitated alkene insertion mechanism and a substrate-free one could be switched by fine-tuning the sterics of catalysts and substrates. This work provides new insights into the role of heteroatom-containing substrates in alkene-insertion-involved reactions, and may help guide designing new catalysis systems. Alkene ; Rare earth ; Sulfide ; Alkylation ; Chemistry ; Migratory insertion ; Combinatorial chemistry ; Catalysis ; Organic chemistry ; Mineralogy Catalytic C–H Functionalization Methods ; Synthesis and Catalytic Reactions ; Sulfur-Based Synthesis Techniques
Authors: Д. В. Моисеев | Brian R. James
Source: Phosphorus, sulfur, and silicon and the related elements (article, 2022-04-03)
Field: Chemistry — Organic Chemistry

Phospha-Mannich reactions of RPH<sub>2</sub>, R<sub>2</sub>PH, and R<sub>3</sub>P Phosphorus-based Mannich-type reactions (phospha-Mannich reactions) of primary or secondary phosphines with carbonyl compounds and amines (R2NH, RNH2, and NH3) provide a powerful synthetic tool in the worldwide search for future ligands. The variety of amines and phosphines available allows for designing and fine-tuning water-soluble, chiral, macrocyclic, pincer, tripodal, photoactive, and etc., phosphine ligands with P–C–N linkage(s) (P,N-acetals). Aminized supports and amine-terminated dendrimers can easily be phosphine-functionalized by phospha-Mannich reactions, and used in reusable heterogeneous catalysts. If CH2O is used as a C-component, its stable adducts with phosphines, that is, RP(CH2OH)2 and R2PCH2OH, are often used in syntheses of P,N-acetals as they are less toxic and non-pyrophoric analogs of the phosphines, whereas other carbonyl compounds are usually converted into imines or iminium salts. In phospha-Mannich reactions, tertiary phosphines form a P+–C–N linkage (P+,N-acetals) that can easily be broken by bases, realizing imine, or iminium cations, and are used as imine/iminium donors in organic syntheses. Iminium ; Phosphine ; Chemistry ; Imine ; Amine gas treating ; Catalysis ; Organic chemistry ; Medicinal chemistry ; Adduct ; Combinatorial chemistry Organophosphorus compounds synthesis ; Asymmetric Hydrogenation and Catalysis ; Chemical Synthesis and Analysis
Authors: Gabriele De Luca | Jonathan Spring | Moloud Kaviani | Simon Jöhr | Marco Campanini | Anna Zakharova | Charles Guillemard | Javier Herrero‐Martín | Rolf Erni | Cínthia Piamonteze | Marta D. Rossell | Ulrich Aschauer | Marta Gibert
Source: Advanced Materials (article, 2022-07-16)
Field: Materials Science — Materials Chemistry

Top‐Layer Engineering Reshapes Charge Transfer at Polar Oxide Interfaces Charge-transfer phenomena at heterointerfaces are a promising pathway to engineer functionalities absent in bulk materials but can also lead to degraded properties in ultrathin films. Mitigating such undesired effects with an interlayer reshapes the interface architecture, restricting its operability. Therefore, developing less-invasive methods to control charge transfer will be beneficial. Here, an appropriate top-interface design allows for remote manipulation of the charge configuration of the buried interface and concurrent restoration of the ferromagnetic trait of the whole film. Double-perovskite insulating ferromagnetic La<sub>2</sub> NiMnO<sub>6</sub> (LNMO) thin films grown on perovskite oxide substrates are investigated as a model system. An oxygen-vacancy-assisted electronic reconstruction takes place initially at the LNMO polar interfaces. As a result, the magnetic properties of 2-5 unit cell LNMO films are affected beyond dimensionality effects. The introduction of a top electron-acceptor layer redistributes the electron excess and restores the ferromagnetic properties of the ultrathin LNMO films. Such a strategy can be extended to other interfaces and provides an advanced approach to fine-tune the electronic features of complex multilayered heterostructures. Materials science ; Ferromagnetism ; Perovskite (structure) ; Heterojunction ; Oxide ; Layer (electronics) ; Charge (physics) ; Electron transfer ; Ferromagnetic material properties ; Thin film ; Optoelectronics ; Nanotechnology ; Electron ; Chemical physics ; Condensed matter physics ; Chemical engineering ; Magnetic field ; Physical chemistry Electronic and Structural Properties of Oxides ; Magnetic and transport properties of perovskites and related materials ; Multiferroics and related materials
Authors: Ludwig Zapf | Sven Peters | Rüdiger Bertermann | Udo Radius | Maik Finze
Source: Chemistry - A European Journal (article, 2022-05-10)
Field: Chemistry — Organic Chemistry

Tricyanoborane‐Functionalized Anionic N‐Heterocyclic Carbenes: Adjustment of Charge and Stereo‐Electronic Properties The 1-methyl-3-(tricyanoborane)imidazolin-2-ylidenate anion (2) was obtained in high yield by deprotonation of the B(CN)<sub>3</sub> -methylimidazole adduct 1. Regarding charge and stereo-electronic properties, anion 2 closes the gap between well-known neutral NHCs and the ditopic dianionic NHC, the 1,3-bis(tricyanoborane)imidazolin-2-ylidenate dianion (IIb). The influence of the number of N-bonded tricyanoborane moieties on the σ-donating and π-accepting properties of NHCs was assessed by quantum chemical calculations and verified by experimental data on 2, IIb, and 1,3-dimethylimidazolin-2-ylidene (IMe, IIa). Therefore NHC 2, which acts as a ditopic ligand via the carbene center and the cyano groups, was reacted with alkyl iodides, selenium, and [Ni(CO)<sub>4</sub> ] yielding alkylated imidazoles 3 and 4, the anionic selenium adduct 5, and the anionic nickel tricarbonyl complex 8, respectively. The results of this study prove that charge, number of coordination sites, buried volume (%V<sub>bur</sub> ) and σ-donor and π-acceptor abilities of NHCs can be effectively fine-tuned via the number of tricyanoborane substituents. Charge (physics) ; Chemistry ; Materials science ; Computational chemistry ; Combinatorial chemistry ; Physics ; Particle physics N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Organoboron and organosilicon chemistry ; Catalytic Cross-Coupling Reactions
Authors: Jiaxin Quan | Ying Guo | Junkai Ma | Deqing Long | Jingjing Wang | Liling Zhang | Yong Sun | Manivannan Kalavathi Dhinakaran | Haibing Li
Source: Frontiers in Chemistry (review, 2022-09-21)
Field: Materials Science — Materials Chemistry

Light-responsive nanochannels based on the supramolecular host–guest system The light-responsive nanochannel of rhodopsin gained wider research interest from its crucial roles in light-induced biological functions, such as visual signal transduction and energy conversion, though its poor stability and susceptibility to inactivation <i>in vitro</i> have limited its exploration. However, the fabrication of artificial nanochannels with the properties of physical stability, controllable structure, and easy functional modification becomes a biomimetic system to study the stimulus-responsive gating properties. Typically, light-responsive molecules of azobenzene (Azo), retinal, and spiropyran were introduced into nanochannels as photo-switches, which can change the inner surface wettability of nanochannels under the influence of light; this ultimately results in the photoresponsive nature of biomimetic nanochannels. Furthermore, the fine-tuning of their stimulus-responsive properties can be achieved through the introduction of host-guest systems generally combined with a non-covalent bond, and the assembling process is reversible. These host-guest systems have been introduced into the nanochannels to form different functions. Based on the host-guest system of light-responsive reversible interaction, it can not only change the internal surface properties of the nanochannel and control the recognition and transmission behaviors but also realize the controlled release of a specific host or guest molecules in the nanochannel. At present, macrocyclic host molecules have been introduced into nanochannels including pillararenes, cyclodextrin (CD), and metal-organic frameworks (MOFs). They are introduced into the nanochannel through chemical modification or host-guest assemble methods. Based on the changes in the light-responsive structure of azobenzene, spiropyran, retinal, and others with macrocycle host molecules, the surface charge and hydrophilic and hydrophobic properties of the nanochannel were changed to regulate the ionic and molecular transport. In this study, the development of photoresponsive host and guest-assembled nanochannel systems from design to application is reviewed, and the research prospects and problems of this photo-responsive nanochannel membrane are presented. Supramolecular chemistry ; Host (biology) ; Nanotechnology ; Chemistry ; Materials science ; Molecule ; Organic chemistry ; Biology ; Ecology Luminescence and Fluorescent Materials ; Supramolecular Self-Assembly in Materials ; Porphyrin and Phthalocyanine Chemistry