jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Jochen A.H. Dreyer | Carsten Gundlach | Claus Erik Weinell | Kim Dam‐Johansen | Søren Kiil
Source: Industrial & Engineering Chemistry Research (article, 2021-04-07)
Field: Materials Science — Polymers and Plastics

Quantitative Characterization of Highly Porous Structures with Fluorescence Microscopy and Microcomputed Tomography In this study, a rapid and versatile methodology for quantitative pore structure characterization is described taking the example of intumescent char. The char porosity and pore structure tend to be difficult to quantify but are decisive for the material’s thermal conductivity and thus performance. The methodology described here uses a fluorescent dye containing epoxy to impregnate the char. After curing, the sample is cut and polished, followed by imaging with a fluorescence microscope. The recorded images are segmented using an open-source interactive machine learning program, followed by automated pore size and porosity measurements. Volume-based three-dimensional (3D) pore size distributions are calculated via stereography and compared to X-ray microcomputed tomography (μ-CT) results. The pore aspect ratio and tortuosity of the solid char phase are also discussed. It is shown that the fluorescence microscopy methodology produces high-resolution images with excellent contrast, while similar pore metrics (porosity of 81.8%, average volume-based pore size of 70.5 μm) to those for μ-CT are obtained. Characterization (materials science) ; Porosity ; Fluorescence ; Microscopy ; Materials science ; Fluorescence microscope ; Tomography ; Chemistry ; Nanotechnology ; Chemical engineering ; Optics ; Composite material ; Physics Polymer Foaming and Composites ; Advanced Polymer Synthesis and Characterization ; Polymer composites and self-healing
Authors: Guiyun Yi
Source: Biomedical Journal of Scientific & Technical Research (article, 2021-07-16)
Field: Materials Science — Materials Chemistry

"Cobalt Doped TiO2/rGO Nanocomposites as Highly Efficient Photocatalyst for Water Purification" An efficient Co-TiO 2 /rGO nanocomposite for photocatalytic degradation of organic dyes were successfully prepared by hydrothermal method with Co(NO 3 ) 2 6H 2 O, titanium dioxide (TiO 2 ) and graphene oxide (GO) as raw materials. The morphology and structure of the as-prepared materials were characterized by XRD, SEM UV-Vis and XPS. Methylene blue (MB), a typical organic dye, was selected as the probe to investigate the effects of the mass ratio of GO and Co-TiO 2 , the dosage amount of catalyst and the cycling performance of Co-TiO 2 /rGO. The results showed that the band gap width of the prepared Co-TiO 2 /rGO composite was about 2.92eV, and when the mass ratio of GO and Co-TiO 2 was 0.01 and the dosage was 20mg, the highest photocatalytic degradation of MB was observed with the degradation rate of 99.7%. Significantly, after 5 times of photocatalytic recycle was conducted, the degradation rate of MB by Co-TiO 2 /rGO was still above 70%. China ; Coal ; Work (physics) ; Engineering ; Waste management ; Chemical engineering ; Environmental science ; Library science ; Political science ; Mechanical engineering ; Computer science ; Law Advanced Nanomaterials in Catalysis ; Water Quality Monitoring and Analysis ; Advanced Photocatalysis Techniques
Authors: Tobias Gensch | Sleight R. Smith | Thomas J. Colacot | Yam Timsina | Guolin Xu | Ben W. Glasspoole | Matthew S. Sigman
Source:  (preprint, 2021-08-13)
Field: Chemistry — Inorganic Chemistry

Design and Application of a Screening Set for Monophosphine Lig-ands in Metal Catalysis In reaction discovery, the search space of discrete reaction parameters such as catalyst structure is often not explored systematical-ly. We have developed a tool set to aid the search of optimal catalysts in the context of phosphine ligands. A virtual library, kra-ken, that is representative of the monodentate P(III)-ligand chemical space was utilized as the basis to represent the discrete lig-ands as continuous variables. Using dimensionality reduction and clustering techniques, we suggested a Phosphine Optimization Screening Set (PHOSS) of 32 commercially available ligands that samples this chemical space completely and evenly. We present the application of this screening set in the identification of active catalyst for various cross-coupling reactions and how well-distributed sampling of the chemical space facilitates identification of active catalysts. Furthermore, we demonstrate how proximi-ty in ligand space can be a useful guide to further explore ligands when very few active catalysts are known. Chemical space ; Virtual screening ; Computer science ; Combinatorial chemistry ; Context (archaeology) ; Catalysis ; Chemistry ; Identification (biology) ; Set (abstract data type) ; Phosphine ; Ligand (biochemistry) ; Dimensionality reduction ; Data mining ; Stereochemistry ; Drug discovery ; Organic chemistry ; Artificial intelligence ; Biology Asymmetric Hydrogenation and Catalysis ; Machine Learning in Materials Science ; Computational Drug Discovery Methods
Authors: Jacek Malinowski | Dagmara Jacewicz | Artur Sikorski | Mariusz Urbaniak | Przemysław Rybiński | Patrycja Parnicka | Adriana Zaleska‐Medynska | Barbara Gawdzik | Joanna Drzeżdżon
Source: Scientific Reports (article, 2021-07-26)
Field: Chemistry — Organic Chemistry

Cat-CrNP as new material with catalytic properties for 2-chloro-2-propen-1-ol and ethylene oligomerizations The contemporary search for new catalysts for olefin oligomerization and polymerization is based on the study of coordinating compounds and/or organometallic compounds as post-metallocene catalysts. However known catalysts are suffered by many flaws, among others unsatisfactory activity, requirement of high pressure or instability at high temperatures. In this paper, we present a new catalyst i.e. the crystalline complex compound possesing high catalytic activity in the oligomerization of olefins, such as 2-chloro-2-propen-1-ol and ethylene under very mild conditions (room temperature, 0.12 bar for ethylene oligomerization, atmospheric pressure for 2-chloro-2-propen-1-ol oligomerization). New material-Cat-CrNP ([nitrilotriacetato-1,10-phenanthroline]chromium(III) tetrahydrate) has been obtained as crystalline form of the nitrilotriacetate complex compound of chromium(III) with 1,10-phenanthroline and characterized in terms of its crystal structure by the XRD method and by multi-analytical investigations towards its physicochemical propeties The yield of catalytic oligomerization over Cat-CrNP reached to 213.92 g · mmol<sup>-1</sup> · h<sup>-1</sup>· bar<sup>-1</sup> and 3232 g · mmol<sup>-1</sup> · h<sup>-1</sup> · bar<sup>-1</sup> for the 2-chloro-2-propen-1-ol and ethylene, respectively. Furthemore, the synthesis of Cat-CrNP is cheap, easy to perform and solvents used during preparation are environmentally friendly. Ethylene ; Catalysis ; Olefin fiber ; Yield (engineering) ; Ethylene glycol ; Chromium ; Materials science ; Chemistry ; Polymerization ; Polymer chemistry ; Organic chemistry ; Metallurgy ; Polymer Organometallic Complex Synthesis and Catalysis ; Carbon dioxide utilization in catalysis ; Synthesis and characterization of novel inorganic/organometallic compounds
Authors: Obieze C. Enudi | Hitler Louis | Goodness J. Ogunwale | Michael T. Kadiri | Prince M. Okibe | Isaiah A. Adejoro | Terkumbur E. Gber | Anthony M.S. Pembere | Adedotun E. Adewale
Source: Research Square (preprint, 2021-10-22)
Field: Chemistry — Physical and Theoretical Chemistry

Understanding the Electronic Interactions, Vertical Excitation Analysis, and the Photovoltaic Properties of 5-(2-ethylhexyl)-1,3-di(furan-2-yl)-4H-thieno[3,4-c]pyrrole-4,6-dione Furan ; Excitation ; Photovoltaic system ; Pyrrole ; Chemistry ; Photochemistry ; Analytical Chemistry (journal) ; Materials science ; Computational chemistry ; Organic chemistry ; Physics ; Engineering ; Electrical engineering ; Quantum mechanics Photochemistry and Electron Transfer Studies ; Organic Electronics and Photovoltaics ; Nonlinear Optical Materials Research
Authors: T. Naveen Kumar | T. Deepa | L. Natrayan | Marabathina Maheedhar | R. Kathiravan
Source: Journal of Nanomaterials (article, 2021-10-04)
Field: Materials Science — Materials Chemistry

Evaluation of Prestrain Annealing Impact on Nanomaterial Sensitization Light metal alloys are extensively used in automotive, aerospace, aircraft, and military sectors since their lightweight leads to reduced energy consumption, increased fuel efficiency, and better environmental protection. In the present situation, nanomaterials are the potential candidate for weight saving in the structural application and can meet stringent government norms. Nanomaterial was heat-treated in the furnace to about a certain temperature and time and then normalized for strengthening. The heat-treated nanomaterial undergoes different forging processes, namely, hot forging and cold forging, using a certain capacity’s hydraulic press. Hence, in this work, an extensive study on the influence of the prestrain annealing, the corrosion rate on differently treated samples, and the effect of sensitization heat treatment on the nanomaterial was done. Nanomaterials ; Materials science ; Forging ; Annealing (glass) ; Automotive industry ; Aerospace ; Metallurgy ; Composite material ; Nanotechnology ; Engineering Carbon Nanotubes in Composites ; Nanotechnology research and applications ; Advanced Materials Characterization Techniques
Authors: Marianna V. Kharlamova | Christian Kramberger
Source: Nanomaterials (article, 2021-11-06)
Field: Materials Science — Materials Chemistry

Temperature-Dependent Growth of 36 Inner Nanotubes inside Nickelocene, Cobaltocene and Ferrocene-Filled Single-Walled Carbon Nanotubes We have investigated the effects of temperature, diameter and metal catalyst type on the growth of inner nanotubes inside metallocene-filled single-walled carbon nanotubes (SWCNTs). The effects on the yield of different chiralities of inner nanotubes were scrutinized by multifrequency Raman spectroscopy. The investigated diameters range from ~0.7 to 1.3 nm and comprise 36 distinct chiralities. For all three investigated metals (Ni, Co, Fe), there is a linear correlation of growth temperature with nanotube diameter. The common slope for these metals is found to be 40.5 °C/Å. The temperature difference between the largest and the smallest diameter tubes amounts to ~230 °C for all three precursors. The growth temperatures are offset by 34 °C from Ni to Co and another 28 °C from Co to Fe. The quantified correlations of temperature, diameter and metal catalyst type provide the basis for engineering the diameter-specific growth of nanotubes. Nickelocene ; Cobaltocene ; Carbon nanotube ; Materials science ; Ferrocene ; Raman spectroscopy ; Metal ; Metallocene ; Catalysis ; Chemical engineering ; Atmospheric temperature range ; Nanotube ; Yield (engineering) ; Nickel ; Nanotechnology ; Composite material ; Chemistry ; Organic chemistry ; Physical chemistry ; Electrochemistry ; Metallurgy Carbon Nanotubes in Composites ; Graphene research and applications ; Molecular Junctions and Nanostructures
Authors: Babajide Oluwagbenga Fatile | Martin Pugh | Mamoun Medraj
Source: Nanomaterials (article, 2021-06-23)
Field: Materials Science — Biomaterials

Optimization of the Electrospun Niobium–Tungsten Oxide Nanofibers Diameter Using Response Surface Methodology The present research aimed to investigate the effect of working parameters on the electrospinning of niobium-tungsten oxide nanofibers and optimize the process using central composite design (CCD) based on the response surface methodology (RSM). An experiment was designed to assess the effects of five variables including the applied voltage (V), spinning distance (D), polymer concentration (P), flow rate (F), and addition of NaCl (N) on the resulting diameter of the nanofibers. Meanwhile, a second-order prediction model of nanofibers diameter was fitted and verified using analysis of variance (ANOVA). The results show that the diameter of the nanofibers was significantly influenced by all the variables except the flow rate. Some second-order and cross factor interactions such as VD, DP, PF, PN, and P<sup>2</sup> also have significant effects on the diameter of the nanofibers. The results of the ANOVA yielded <i>R</i><sup>2</sup> and adjusted <i>R</i><sup>2</sup> values of 0.96 and 0.93 respectively, this affirmed that the predictive model fitted well with the experimental data. Furthermore, the process parameters were optimized using the CCD method and a maximum desirability function of 226 nm was achieved for the diameter of the nanofibers. This is very close to the 233 nm diameter obtained from a confirmatory experiment using the optimum conditions. Therefore, the model is representative of the process, and it could be used for future studies for the reduction of the diameter of electrospun nanofibers. Nanofiber ; Response surface methodology ; Materials science ; Electrospinning ; Central composite design ; Composite material ; Tungsten ; Composite number ; Polymer ; Volumetric flow rate ; Mathematics ; Statistics ; Thermodynamics ; Metallurgy ; Physics Electrospun Nanofibers in Biomedical Applications ; Conducting polymers and applications ; Polymer Nanocomposite Synthesis and Irradiation
Authors: Leila Abylgazina | Irena Senkovska | Stefan Kaskel
Source: ChemRxiv (preprint, 2021-01-21)
Field: Chemistry — Inorganic Chemistry

Logic and Symbolism of Switchable Porous Framework Materials Metal-Organic Frameworks (MOFs) are highly porous materials composed of organic linkers connected by inorganic nodes. A unique subset of MOFs shows switchability, the ability to switch between at least two distinct structures differing significantly in porosity. These unique guest dependent pore opening and closing processes offer new opportunities in gas separation, selective recognition, sensing and energy storage. However, the factors affecting switchability are poorly understood. Network topology, micromechanics of building blocks and their hinges, but also particle size, defects, agglomeration, desolvation conditions etc. are convoluted into the responsiveness of the system. In essence all factors are a consequence of the materials history including synthesis procedure and desolvation but also all subsequent handling steps such as mechanical and adsorption stress leading to a complex interplay of factors which are difficult to express clearly by ordinary writing systems, chemical or mathematical symbols without loss of intuitive understanding. Here we propose a symbolic language for the rationalization of switchability emphasizing the history dependent responsivity of many dynamic frameworks and their stimuli induced 1st order phase transitions. Color representations of the guest and host offer an intuitive understanding of switchability phenomena even for non-experts. The system follows a bivalent logic inspired by Freges Begriffsschrift providing a fundamental logic structure for the rationalization of statements and representation of logic gates. Materials science ; Computer science ; Nanotechnology ; Porosity Metal-Organic Frameworks: Synthesis and Applications ; Polyoxometalates: Synthesis and Applications ; Molecular Sensors and Ion Detection
Authors: Yahya Saleh | Vishnu Sanjay | Armin Iske | Andrey Yachmenev | Jochen Küpper
Source: arXiv (Cornell University) (article, 2021-04-01)
Field: Materials Science — Materials Chemistry

Active learning of potential-energy surfaces of weakly-bound complexes with regression-tree ensembles Several pool-based active learning algorithms (AL) were employed to model potential energy surfaces (PESs) with a minimum number of electronic structure calculations. Theoretical and empirical results suggest that superior strategies can be obtained by sampling molecular structures corresponding to large uncertainties in their predictions while at the same time not deviating much from the true distribution of the data. To model PESs in an AL framework we propose to use a regression version of stochastic query by forest, a hybrid method that samples points corresponding to large uncertainties while avoiding collecting too many points from sparse regions of space. The algorithm is implemented with decision trees that come with relatively small computational costs. We empirically show that this algorithm requires around half the data to converge to the same accuracy in comparison to the uncertainty-based query-by-committee algorithm. Moreover, the algorithm is fully automatic and does not require any prior knowledge of the PES. Simulations on a 6D PES of \pyrrolew show that $\mathord{<}15\,000$ configurations are enough to build a PES with a generalization error of 16~\invcm, whereas the final model with around 50\,000 configurations has a generalization error of 11~\invcm. Generalization ; Computer science ; Algorithm ; Sampling (signal processing) ; Tree (set theory) ; Regression ; Decision tree ; Space (punctuation) ; Energy (signal processing) ; Mathematical optimization ; Artificial intelligence ; Mathematics ; Statistics Machine Learning in Materials Science ; Computational Drug Discovery Methods ; Fuel Cells and Related Materials
Authors: Mark J. Spillman | Kenneth Shankland
Source: CrystEngComm (article, 2021-01-01)
Field: Materials Science — Materials Chemistry

GALLOP: accelerated molecular crystal structure determination from powder diffraction data A new GPU-accelerated algorithm delivers state-of-the-art performance for molecular crystal structure determination from powder diffraction data. Powder diffraction ; Diffraction ; Materials science ; Crystal (programming language) ; Crystallography ; Crystal structure ; Chemistry ; Computer science ; Optics ; Physics X-ray Diffraction in Crystallography ; Crystallography and molecular interactions ; Machine Learning in Materials Science
Authors: Susi Lehtola | Antti J. Karttunen
Source:  (preprint, 2021-11-15)
Field: Chemistry — Physical and Theoretical Chemistry

Free and Open Source Software for Computational Chemistry Education Abstract Long in the making, computational chemistry for the masses [J. Chem. Educ. 1996, 73, 104] is finally here. Our brief review on various free and open source software (FOSS) quantum chemistry packages points out the existence of software offering a wide range of functionality, all the way from approximate semiempirical calculations with tight-binding density functional theory to sophisticated ab initio wave function methods such as coupled-cluster theory, both for molecular and for solid-state systems. Combined with the remarkable increase in the computing power of personal devices, which now rivals that of the fastest supercomputers in the world of the 1990s, we demonstrate that a decentralized model for teaching computational chemistry is now possible thanks to FOSS computational chemistry packages, enabling students to perform reasonable modeling on their own computing devices, in the bring your own device (BYOD) scheme. FOSS software can be made trivially simple to install and keep up to date, eliminating the need for departmental support, and also enables comprehensive teaching strategies, as various algorithms' actual implementations can be used in teaching. We exemplify what kinds of calculations are feasible with four FOSS electronic structure programs, assuming only extremely modest computational resources, to illustrate how FOSS packages enable decentralized approaches to computational chemistry education within the BYOD scheme. FOSS also has further benefits: the open access to the source code of FOSS packages democratizes the science of computational chemistry, and FOSS packages can be used without limitation also beyond education, in academic and industrial applications, for example. For these reasons, we believe FOSS will become ever more pervasive in computational chemistry. Computer science ; Software ; Computational science ; Implementation ; Theoretical computer science ; Chemistry ; Software engineering ; Programming language Various Chemistry Research Topics ; Scientific Computing and Data Management ; Surface Chemistry and Catalysis
Authors: Adrien Marizy | Grégory Geneste | Gastón Garbarino | Paul Loubeyre
Source: RSC Advances (article, 2021-01-01)
Field: Materials Science — Materials Chemistry

High pressure polymorphism of LiBH<sub>4</sub> and of NaBH<sub>4</sub> The pressure-induced structural changes in LiBH<sub>4</sub> and in NaBH<sub>4</sub> have been investigated experimentally up to 290 GPa by coupling Raman spectroscopy, infrared absorption spectroscopy and synchrotron X-ray diffraction. This data set is also analysed in the light of Density Functional Theory calculations performed up to 600 GPa. The [BH<sub>4</sub>]<sup>-</sup> unit appears to be remarkably resistant under pressure. NaBH<sub>4</sub> remains stable in the known <i>Pnma</i> γ-phase up to 200 GPa and calculations predict a transition to a metallic polymeric <i>C</i>2/<i>c</i> phase at about 480 GPa. LiBH<sub>4</sub> is confirmed to exhibit a richer polymorphism. A new <i>Pnma</i> orthorhombic phase VI is found to be stable above 60 GPa and there are hints of a possible phase VII above 160 GPa. DFT calculations predict that two other high pressure LiBH<sub>4</sub> phases should appear at about 290 and 428 GPa. A very slight solubility of H<sub>2</sub> inside phases II, III and V of LiBH<sub>4</sub> is observed. A NaBH<sub>4</sub>(H<sub>2</sub>)<sub>0.5</sub> complex is predicted to be stable above 150 GPa. Orthorhombic crystal system ; Synchrotron ; Raman spectroscopy ; Density functional theory ; Polymorphism (computer science) ; Crystallography ; Solubility ; Chemistry ; Diffraction ; Phase (matter) ; Infrared spectroscopy ; Metal ; Absorption spectroscopy ; Materials science ; Analytical Chemistry (journal) ; Physical chemistry ; Crystal structure ; Computational chemistry Hydrogen Storage and Materials ; Advanced Chemical Physics Studies ; High-pressure geophysics and materials
Authors: Daniil A. Kitchaev | Anton Van der Ven
Source: Physical Review Materials (article, 2021-12-09)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Tuning magnetic antiskyrmion stability in tetragonal inverse Heusler alloys The identification of materials supporting complex, tunable magnetic order at ambient temperatures is foundational to the development of new magnetic device architectures. We report the design of $\mathrm{Mn}{}_{2}XY$ tetragonal inverse Heusler alloys that are capable of hosting magnetic antiskyrmions whose stability is sensitive to elastic strain. We first construct a universal magnetic Hamiltonian capturing the short- and long-range magnetic order which can be expected in these materials. This model reveals critical combinations of magnetic interactions that are necessary to approach a magnetic phase boundary, where the magnetic structure is highly susceptible to small perturbations such as elastic strain. We then computationally search for quaternary $\mathrm{Mn}{}_{2}({X}_{1},{X}_{2})Y$ alloys where these critical interactions may be realized and which are likely to be synthesizable in the inverse Heusler structure. We identify the $\mathrm{Mn}{}_{2}\mathrm{Pt}{}_{1\ensuremath{-}z}{X}_{z}\mathrm{Ga}$ family of materials with $X=$ Au, Ir, Ni as an ideal system for accessing all possible magnetic phases, with several critical compositions where magnetic phase transitions may be actuated mechanically. Materials science ; Tetragonal crystal system ; Condensed matter physics ; Inverse ; Hamiltonian (control theory) ; Crystallography ; Order (exchange) ; Physics ; Crystal structure ; Chemistry ; Mathematics ; Geometry Heusler alloys: electronic and magnetic properties ; Magnetic properties of thin films ; Magnetic and transport properties of perovskites and related materials