jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Shreejaya Sivadas | PK Omre | NC Shahi | TP Singh | Anil Kumar | Annu | Sheeba Malik
Source: International Journal of Advanced Biochemistry Research (article, 2024-10-01)
Field: Materials Science — Biomaterials

Biodegradable film using pine needle fibre and cassava starch: A sustainable packaging solution Use of plastic food packaging has long been debated due to its negative environmental impact. As a result of this, the need to develop sustainable and biodegradable packaging continuously grows, particularly that using plant-based materials. The study was undertaken to develop biodegradable film from Pine Needle Fiber (PNF), Cassava Starch (CS), Polyvinyl Alcohol (PVOH) blend through a casting technique. It aimed to standardize the process for preparation of biodegradable packaging films physical, mechanical, and biodegradable properties. The mechanical properties and biodegradability of the resulting CS-PVOH/PNF films were evaluated. The films demonstrated improved tensile strength and elongation at break, with optimal values of 10 MPa Tensile Strength and 191% Elongation. The Soil Burial Method showed rapid biodegradation, with all films degrading within 10 days. Water absorption tests revealed a decrease in water absorption with increasing PNF content, confirming the suitability of the CS-PVOH/PNF films as eco-friendly, flexible packaging materials with desirable mechanical and biodegradable properties. On the other hand, expanding the fiber and starch extent in film framework decayed both rigidity and percent extension at break of the film. The results revealed that addition of pine needle fibre has lowered water absorption and increased the Tensile Strength and Elongation as compared to films without pine needle fibre. Considering all the parameters it can be said that the biodegradable film (CS-PVOH/PNF) mix was developed which can be viewed as reasonable, adaptable by a straightforward and harmless to the ecosystem cycle. Starch ; Materials science ; Polymer science ; Food packaging ; Pulp and paper industry ; Composite material ; Horticulture ; Food science ; Chemistry ; Engineering ; Biology Nanocomposite Films for Food Packaging
Authors: Abhilash Patra | George Baffour Pipim | Anna I. Krylov | Shaama Mallikarjun Sharada
Source: ChemRxiv (preprint, 2024-01-04)
Field: Chemistry — Physical and Theoretical Chemistry

Performance of density functionals for excited-state properties of isolated chromophores and exciplexes: Emission spectra, solvatochromic shifts, and charge-transfer character This study assesses the performance of various meta-generalized gradient approximation (meta-GGA), global hybrid, and range-separated hybrid (RSH) density functionals in capturing excited-state properties of organic chromophores and their excited-state complexes (exciplexes). Motivated by their uses in solar energy harvesting and photoredox CO2 reduction, we use oligo-(p-phenylenes) and their excited-state complexes with triethylamine as model systems. We focus on the fluorescence properties of these systems, specifically emission energies, solvatochromic shifts, and wavefunction characteristics. The latter is described using reduced quantities such as natural transition orbitals (NTOs) and exciton descriptors. The functionals are benchmarked against the experimental fluorescence spectra and the equation-of-motion coupled-cluster method with single and double excitations (EOM-CCSD). The results show that, both in isolated chromophores and in exciplexes, meta-GGA functionals drastically underestimate the emission energies, and exhibit significant exciton delocalization and anti-correlation between electron and hole pair. The performance of global hybrid functionals depends strongly on the percentage of exact exchange. RSH GGAs are the best-performing functionals identified in our study, with ωPBE demonstrating the best agreement with experimental results. RSH meta-GGAs often overestimate emission energies in exciplexes and yield larger hole NTOs. Their performance can be improved by optimally tuning the range-separation parameter. Chromophore ; Excited state ; Delocalized electron ; Exciton ; Solvatochromism ; Hybrid functional ; Density functional theory ; Wave function ; Molecular physics ; Emission spectrum ; Fluorescence ; Materials science ; Atomic physics ; Spectral line ; Chemistry ; Physics ; Photochemistry ; Computational chemistry ; Quantum mechanics Photochemistry and Electron Transfer Studies ; Perovskite Materials and Applications ; Spectroscopy and Quantum Chemical Studies
Authors: Xiao‐Hui Ma | Jiang‐Feng Xing | Ling Chai | Qingsong Deng | Xuan‐Wen Chen | Hai‐Feng Su | Chao Li | Yuan‐Zhi Tan
Source: Organic Materials (article, 2024-03-20)
Field: Chemistry — Organic Chemistry

Diazananographene with Quadruple [5]Helicene Units: Synthesis, Optical Properties, and Supramolecular Assembly A helical diazananographene (1) was successfully synthesized by employing sterically hindered t-butyl groups to inhibit further dehydrocyclization of [5]helicene units. These t-butyl groups stabilized the conformation of [5]helicene units, thus resulting in three stable conformers of 1, comprising a pair of enantiomers (1-(P, P, P, P) and 1-(M, M, M, M)) and a mesomer (1-(P, P, M, M)). In comparison to its planar analogs, helical 1 exhibited broadened peaks in both its absorption and emission spectra, leading to an increase in the emission quantum yield from 0.3 to 0.6. The significantly enhanced radiative decay rate (k r) accounted for the increase in the quantum yield of 1. Additionally, it was observed that the compound could be fully protonated upon the addition of an equivalent acid. Furthermore, 1 assembled into a chiral trimeric metallosupramolecular complex upon coordination with the PdII units. Both protonated 1 and the metallosupramolecular complex exhibited an enhanced circular dichroic response. These findings revealed that the incorporation of a helical structure and pyridinic nitrogen-doping into the nanographene can allow the synthesis of responsive chiroptical graphenic materials, which could serve as fundamental components for constructing chiral hierarchical metallosupramolecular structures. Helicene ; Supramolecular chemistry ; Supramolecular assembly ; Nanotechnology ; Materials science ; Chemistry ; Crystallography ; Organic chemistry ; Molecule ; Crystal structure Synthesis and Properties of Aromatic Compounds ; Fullerene Chemistry and Applications ; Nonlinear Optical Materials Research
Authors: Jie Wang | Irán Rojas‐León | Niklas Rinn | Lukas Guggolz | Ferdinand Ziese | Simone Sanna | Nils W. Rosemann | Stefanie Dehnen
Source: Angewandte Chemie International Edition (article, 2024-08-19)
Field: Materials Science — Materials Chemistry

Strain‐Induced Structural Rearrangement Towards a White‐Light‐Emitting Adamantane‐Type Cluster Dimer Group 14/16 adamantane-type hybrid clusters of the type [(RT)<sub>4</sub>E<sub>6</sub>] (T=group 14 element, E=group 16 element, R=organic group) have been reported to emit white-light when irradiated in an amorphous state with a continuous-wave (CW) infrared laser diode. This effect is enhanced if the cluster core is varied from a binary to a more complex composition. To further explore this phenomenon, we synthesized clusters with a multinary R/R'-T/T'-E/E' composition, including isolobal replacement of E with CH<sub>2</sub>, in [(2-NpSi){CH<sub>2</sub>Sn(S)Ph}<sub>3</sub>] (1, Np=naphthyl). When expanding one of the CH<sub>2</sub> moieties to a C<sub>2</sub>H<sub>4</sub> group, thus generating a R/R'-T/T'-E/E'/E'' cluster composition, we unexpectedly observed a dimerization of the initially formed, yet non-isolable adamantane-like cluster [(2-NpSi){CH<sub>2</sub>Sn(S)Ph}<sub>2</sub>{C<sub>2</sub>H<sub>4</sub>Sn(S)Ph}] (2) to [(2-NpSi){CH<sub>2</sub>Sn(S)Ph}<sub>2</sub>{C<sub>2</sub>H<sub>4</sub>Sn(S)Ph}]<sub>2</sub> (3), exhibiting a heretofore unprecedented cluster architecture. Both monomeric 1 and dimeric 3, show white-light emission as thin films. The nonlinear optical response of the compounds was also modelled with DFT methods. Adamantane ; Dimer ; Cluster (spacecraft) ; White light ; Strain (injury) ; Crystallography ; Diamondoid ; Chemistry ; Stereochemistry ; Materials science ; Molecule ; Biology ; Computer science ; Optoelectronics Polyoxometalates: Synthesis and Applications ; Porphyrin and Phthalocyanine Chemistry ; Carbon dioxide utilization in catalysis
Authors: Magdalena Dryś | Tetyana V. Koso | Petri Kilpeläinen | Katja T. Rinne‐Garmston | Aleksandar R. Todorov | Susanne Κ. Wiedmer | Vladimir Iashin | Alistair W. T. King
Source: Macromolecular Rapid Communications (article, 2024-04-02)
Field: Materials Science — Biomaterials

Structural Characterization of 6‐Halo‐6‐Deoxycelluloses by Direct‐Dissolution Solution‐State NMR Spectroscopy Regioselective modifications of cellulose using activated cellulose derivatives such as 6-halo-6-deoxycelluloses provide a convenient approach for developing sustainable products with properties tailored to specific applications. However, maintaining precise regiochemical control of substituent distribution in 6-halo-6-deoxycelluloses is challenging due to their insolubility in most common solvents and the resulting difficulties in precise structure elucidation by modern instrumental analytical techniques. Herein, an accessible NMR-based approach toward detailed characterization of 6-halo-6-deoxycelluloses, including the determination of the degrees of substitution at carbon 6 (DS<sub>6</sub>), is presented. It is shown that the direct-dissolution cellulose solvent, tetrabutylphosphonium acetate:DMSO-d<sub>6</sub>, converts 6-halo-6-deoxycelluloses to 6-monoacetylcellulose, enabling in situ solution-state NMR measurements. A range of 1D and 2D NMR experiments is used to demonstrate the quantitivity of the conversion and provide optimum dissolution conditions. In comparison with other NMR-based derivatization protocols for elucidating the structure of 6-halo-6-deoxycelluloses, the presented approach offers major advantages in terms of accuracy, speed, and simplicity of analysis, and minimal requirements for reagents or NMR instrumentation. Cellulose ; Dissolution ; Nuclear magnetic resonance spectroscopy ; Chemistry ; Characterization (materials science) ; Reagent ; Combinatorial chemistry ; Materials science ; Organic chemistry ; Nanotechnology Advanced Cellulose Research Studies ; Catalysis for Biomass Conversion ; Carbohydrate Chemistry and Synthesis
Authors: Eleni F. Iliopoulou | Eleni Pachatouridou | Angelos A. Lappas
Source: Nanomaterials (article, 2024-01-04)
Field: Materials Science — Materials Chemistry

Novel Nanostructured Pd/Co-Alumina Materials for the Catalytic Oxidation of Atmospheric Pollutants Cobalt-doped alumina catalysts were prepared using different methods, either conventional wet impregnation (WI) and/or advanced spray impregnation (SI), and they were evaluated as novel oxidation catalysts for CO and MeOH oxidation. The spray impregnation technique was used with the aim of achieving the synthesis of core-shell catalytic nanostructures to secure the chemical/thermal stability of active sites on the catalyst carrier. The catalysts were further promoted with a low Pd content (0.5 wt.%) incorporated via either incipient wetness impregnation (DI) or spray impregnation. The results revealed the superior performance of the spray-impregnated catalysts (Co/γ-Al<sub>2</sub>O<sub>3</sub>-SI) for both reactions. The deposition of Co oxide on the outer surface of the alumina particle (SEM images) and the availability of the active Co phase resulted in the enhancement of the Co/γ-Al<sub>2</sub>O<sub>3</sub> catalysts' oxidation activity. Pd incorporation increased the catalysts' reducibility (TPR-H<sub>2</sub>) and improved the catalysts' performance for both reactions. However, the Pd incorporation method affected the catalytic performance; with the SI method, the active phase of Co<sub>3</sub>O<sub>4</sub> was probably covered with PdO and was not available for the oxidation reactions. On the contrary, the incorporation of Pd with the DI method resulted in a better dispersion of PdO all over the Co/Al catalyst surface, maintaining available Co active sites and a better Pd-Co interaction. MeOH desorption studies revealed the methanol oxidation mechanism: the Co/Al catalysts promoted the partial oxidation of MeOH to formaldehyde (HCHO) and dehydration to dimethyl ether (DME), while the Pd-based Co/Al catalysts enhanced the complete oxidation of methanol to CO<sub>2</sub> and H<sub>2</sub>O. Catalysis ; Incipient wetness impregnation ; Cobalt ; Methanol ; Cobalt oxide ; Dimethyl ether ; Materials science ; Oxide ; Chemical engineering ; Inorganic chemistry ; Dispersion (optics) ; Chemistry ; Selectivity ; Organic chemistry ; Metallurgy Catalytic Processes in Materials Science ; Catalysis and Oxidation Reactions ; Catalysts for Methane Reforming
Authors: Sergio Moles Quintero | Jose C. Mira-Martínez | Ya Zou | Marcos Díaz‐Fernández | Pedro G. Boj | Jishan Wu | María A. Díaz‐García | José Manuel Marín‐Beloqui | Juan Casado
Source: Journal of Materials Chemistry C (article, 2024-01-01)
Field: Materials Science — Materials Chemistry

Triplet formation inhibits amplified spontaneous emission in perylene-based polycyclic aromatic hydrocarbons Three similar polycyclic aromatic hydrocarbon display outstanding emission properties, but only one displays amplified stimulated emission. The lack of available triplet states hinders the triplet formation allowing the amplified stimulated emission. Perylene ; Materials science ; Photochemistry ; Aggregation-induced emission ; Polycyclic aromatic hydrocarbon ; Fluorescence ; Environmental chemistry ; Molecule ; Organic chemistry ; Chemistry ; Optics Luminescence and Fluorescent Materials ; Synthesis and Properties of Aromatic Compounds ; Photoreceptor and optogenetics research
Authors: Vignesh Pattathil | Conor Pranckevicius
Source: Chemical Communications (article, 2024-01-01)
Field: Chemistry — Organic Chemistry

Aromaticity transfer in an annulated 1,4,2-diazaborole: facile access to <i>C</i> <sub>s</sub> symmetric 1,4,2,5-diazadiborinines A tricyclic annulated 1,4,2-diazaborole is readily accessed <i>via</i> reaction of a bidentate pyridyl-carbene ligand with MesBBr<sub>2</sub> followed by reduction. Dearomatization of the flanking rings is shown to increase reactivity of this heterocycle in the form of a B-centred alkylation with MeI. Its reaction with hydrido-, fluoro-, and chloro-boranes reveal an unprecedented ring expansion reaction to form a diverse family of B<sub>2</sub>C<sub>2</sub>N<sub>2</sub> heterocycles, reduction of which allows facile access to the first examples of <i>C</i><sub>s</sub> symmetric 1,4,2,5-diazadiborinines. DFT calculations have shed light on the electronic structures of the reduced species and provide insight into mechanistic aspects of the observed ring-expansion. Aromaticity ; Chemistry ; Transfer (computing) ; Stereochemistry ; Combinatorial chemistry ; Medicinal chemistry ; Computational chemistry ; Organic chemistry ; Computer science ; Parallel computing ; Molecule Organoboron and organosilicon chemistry ; Boron Compounds in Chemistry ; Synthesis and Properties of Aromatic Compounds
Authors: Bharath Ravindran | Timotheos Agathocleous | Beate Oswald-Tranta | Ewald Fauster | Michael Feuchter
Source: Journal of Composites Science (article, 2024-03-29)
Field: Materials Science — Polymers and Plastics

Impact Characteristics and Repair Approaches of Distinct Bio-Based Matrix Composites: A Comparative Analysis Increasing global concerns regarding environmental issues have driven significant advancements in the development of bio-based fiber reinforced polymer composites. Despite extensive research on bio-composites, there remains a noticeable gap in studies specifically addressing the challenges of repairing bio-composites for circular economy adoption. Traditional repair techniques for impacted composites, such as patching or scarf methods, are not only time-consuming but also require highly skilled personnel. This paper aims to highlight cost-effective repair strategies for the restoration of damaged composites, featuring flax fiber as the primary reinforcement material and distinct matrix systems, namely bio-based epoxy and bio-based vitrimer matrix. Glass fiber was used as a secondary material to validate the bio-based vitrimer matrix. The damage caused specifically by low impact is detrimental to the structural integrity of the composites. Therefore, the impact resistance of the two composite materials is evaluated using instrumented drop tower tests at various energy levels, while thermography observations are employed to assess damage evolution. Two distinct repair approaches were studied: the resin infiltration repair method, employing bio-based epoxy, and the reconsolidation (self-healing) repair method, utilizing the bio-based vitrimer matrix. The efficiency of these repair methods was assessed through active thermography and compression after impact tests. The repair outcomes demonstrate successful restoration and the maintenance of ultimate strength at an efficiency of 90% for the re-infiltration repair method and 92% for the reconsolidation repair method. Composite material ; Matrix (chemical analysis) ; Materials science Natural Fiber Reinforced Composites ; Additive Manufacturing and 3D Printing Technologies ; Innovations in Concrete and Construction Materials
Authors: Augustinas Galeckas | Adrian Cernescu | Anna Kaźmierczak-Bałata | Javier García‐Fernández | Calliope Bazioti | Alexander Azarov | Ji Hyeon Park | Dae‐Woo Jeon | Hung-Kai Lee | Won‐Jae Lee | Rui Zhu | Zengxia Mei | Øystein Prytz | Andrej Kuznetsov
Source: arXiv (Cornell University) (preprint, 2024-12-18)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Optical library of Ga2O3 polymorphs Gallium oxide is a novel advanced material gaining increasing attention for its unique combination of functional properties. It forms in several phases or polymorphs - α, β, γ, and κ - having variable properties because of different lattice symmetries. Optical properties are of particular importance as they determine specific device applications and can also be used for phase identification. However, a direct comparison of optical polymorph signatures, including such critical parameters as bandgaps, is challenging due to the scattered, limited, or even absent data for certain phases in the literature. To address this issue, in the present work we systematically cross-correlate optical emission and absorption features of α, β, γ, and κ thin films, as well as differently oriented β-phase bulk crystals and γ/β double polymorph structures. We demonstrate that the optical bandgap and emission features scale consistently across these polymorphs upon minimization of the methodological uncertainties. As a result, this work provides a comparative library of near- and far-field optical signatures of the polymorphs for use by the multidisciplinary research community working with gallium oxide. Materials science ; Crystallography ; Chemistry Ga2O3 and related materials ; Semiconductor materials and devices ; GaN-based semiconductor devices and materials
Authors: Mauricio Rodríguez‐Mayorga | Pau Besalú‐Sala | Á. J. Pérez‐Jiménez | J. C. Sancho-Garcı́a
Source: Journal of Computational Chemistry (article, 2024-01-11)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Application to nonlinear optical properties of the RSX‐QIDH double‐hybrid range‐separated functional The effective calculation of static nonlinear optical properties requires a considerably high accuracy at a reasonable computational cost, to tackle challenging organic and inorganic systems acting as precursors and/or active layers of materials in (nano-)devices. That trade-off implies to obtain very accurate electronic energies in the presence of externally applied electric fields to consequently obtain static polarizabilities ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub><mml:mrow><mml:mi>α</mml:mi></mml:mrow> <mml:mrow><mml:mi>i</mml:mi> <mml:mi>j</mml:mi></mml:mrow> </mml:msub> </mml:mrow> </mml:math> ) and hyper-polarizabilities ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub><mml:mrow><mml:mi>β</mml:mi></mml:mrow> <mml:mrow><mml:mi>i</mml:mi> <mml:mi>j</mml:mi> <mml:mi>k</mml:mi></mml:mrow> </mml:msub> </mml:mrow> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub><mml:mrow><mml:mi>γ</mml:mi></mml:mrow> <mml:mrow><mml:mi>i</mml:mi> <mml:mi>j</mml:mi> <mml:mi>k</mml:mi> <mml:mi>l</mml:mi></mml:mrow> </mml:msub> </mml:mrow> </mml:math> ). Density functional theory is known to provide an excellent compromise between accuracy and computational cost, which is however largely impeded for these properties without introducing range-separation techniques. We thus explore here the ability of a modern (double-hybrid and range-separated) Range-Separated eXchange Quadratic Integrand Double-Hybrid exchange-correlation functional to compete in accuracy with more costly and/or tuned methods, thanks to its robust and parameter-free nature. Range (aeronautics) ; Nonlinear system ; Nonlinear optical ; Materials science ; Hybrid functional ; Density functional theory ; Statistical physics ; Chemical physics ; Biological system ; Chemistry ; Physics ; Computational chemistry ; Quantum mechanics ; Biology ; Composite material Nonlinear Optical Materials Research ; Photochemistry and Electron Transfer Studies ; Spectroscopy and Laser Applications
Authors: Fabian Garmroudi | Illia Serhiienko | Simone Di Cataldo | Michael Parzer | Alexander Riss | Matthias Grasser | Simon Stockinger | Sergii Khmelevskyi | Kacper Pryga | Bartłomiej Wiendlocha | Karsten Held | Takao Mori | E. Bauer | Andrej Pustogow
Source: arXiv (Cornell University) (preprint, 2024-04-11)
Field: Materials Science — Materials Chemistry

High thermoelectric power factor through topological flat bands Thermoelectric (TE) materials are useful for applications such as waste heat harvesting or efficient and targeted cooling. While various strategies towards superior thermoelectrics through a reduction of the lattice thermal conductivity have been developed, a path to enhance the power factor is pressing. Here, we report large power factors up to 5 mW m$^{-1}$ K$^{-2}$ at room temperature in the kagome metal Ni$_3$In$_{1-x}$Sn$_x$. This system is predicted to feature almost dispersionless flat bands in conjunction with highly dispersive Dirac-like bands in its electronic structure around the Fermi energy $E_\text{F}$ [L. Ye et al., Nature Physics 1-5 (2024)]. Within this study, we experimentally and theoretically showcase that tuning this flat band precisely below $E_\text{F}$ by chemical doping $x$ boosts the Seebeck coefficient and power factor, as highly mobile charge carriers scatter into the flat-band states. Our work demonstrates the prospect of engineering extremely flat and highly dispersive bands towards the Fermi energy in kagome metals and introduces topological flat bands as a novel tuning knob for thermoelectrics. Topology (electrical circuits) ; Power factor ; Factor (programming language) ; Power (physics) ; Thermoelectric effect ; Physics ; Geometry ; Mathematics ; Materials science ; Computer science ; Combinatorics ; Quantum mechanics Advanced Thermoelectric Materials and Devices