jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Fahime Dehghan | Alimorad Rashidi | Fahime Parvizian | Abdolreza Moghadassi
Source: Scientific Reports (article, 2023-12-05)
Field: Chemistry — Inorganic Chemistry

Pore size engineering of cost-effective all-nanoporous multilayer membranes for propane/propylene separation In this study, a new multi-layer hybrid nanocomposite membrane named MFI/GO/ZIF-8 has been synthesized. This membrane combines three nanoporous materials with different morphologies in one membrane without using polymer materials. This allows access to a previously accessible region of very high permeability and selectivity properties. In addition to introducing a new and efficient MFI/GO/ZIF-8 membrane in this work, controlling the pore size of the zeolite layer has been investigated to increase the selectivity and permeability of propylene. The membrane was made using a solvent-free hydrothermal method and a layer-by-layer deposition method. To control the pore size of the MFI layer, a two-step synthesis strategy has been implemented. In the first step, three key parameters, including crystallization time, NaOH concentration and aging time of initial suspension, are controlled. In the second step, the effect of three additional parameters including hydrothermal time, hydrothermal temperature and NH<sub>4</sub>F concentration has been investigated. The results show that the optimal pore size has decreased from 177.8 nm to 120.53 nm (i.e., 32.2%). The MFI/GO/ZIF-8 membrane with fine-tuned crystal size in the zeolite layer was subjected to detailed tests for propylene selectivity and permeability. The structural characteristics of the membrane were also performed using FT-IR, XRD, FESEM and EDS techniques. The results show that the synergistic interaction between the three layers in the nanocomposite membrane significantly improves the selectivity and permeability of propylene. The permeability and selectivity of propylene increased from 50 to 60 GPU and from 136 to 177, respectively, before and after precise crystal size control. MFI/GO/ZIF-8 membrane by controlling the pore size of the zeolite layer shows a significant increase of 23.1% in selectivity and 16.7% in propylene permeability compared to the initial state. Also, due to the precise synthesis method, the absence of solvent and the use of cheap support, the prepared membrane is considered an environmentally friendly and low-cost membrane. This study emphasizes the potential of increasing the selectivity and permeability of propylene in the MFI/GO/ZIF-8 hybrid membrane by controlling the crystal size of the zeolite layer. Propane ; Nanoporous ; Membrane ; Chemical engineering ; Materials science ; Chemistry ; Nanotechnology ; Organic chemistry ; Engineering ; Biochemistry Zeolite Catalysis and Synthesis ; Metal-Organic Frameworks: Synthesis and Applications ; Membrane Separation and Gas Transport
Authors: Pablo A. Denis
Source: Computational and Theoretical Chemistry (article, 2023-01-17)
Field: Materials Science — Materials Chemistry

Theoretical characterization of codoped bilayer graphene Bilayer graphene ; Graphene ; Bilayer ; Monolayer ; Chemistry ; Doping ; Band gap ; Stacking ; Condensed matter physics ; Dopant ; Covalent bond ; Nanotechnology ; Materials science ; Membrane ; Physics Graphene research and applications ; Quantum and electron transport phenomena ; 2D Materials and Applications
Authors: Sergey P. Verevkin | Arina V. Elbakari | Sergey V. Vostrikov | Ruslan N. Nagrimanov | Mikhail A. Varfolomeev
Source: Journal of Chemical & Engineering Data (article, 2023-08-02)
Field: Chemistry — Organic Chemistry

Renewable Platform Chemicals: Evaluation of Experimental Data for Alkyl Benzoates with Complementary Measurements, Structure–Property Correlations, and Quantum Chemical Calculations Alkyl benzoates (or esters of benzoic acid) are important preservatives in the food and beverage industry. The development of new and effective synthesis pathways from renewable sources opens a window of opportunity for their large-scale production. Consequently, new areas of application for alkyl benzoates, e.g., conversion to platform chemicals or hydrogen storage, can be considered. The production and conversion of alkyl benzoates usually involve several steps, so controlling selectivity and yield is a challenge for these new pathways. Success depends on fine-tuning the distribution between thermodynamic and kinetic products. The latter is possible if reliable thermochemical and thermophysical data on the reactants are available. The thermochemical properties of a homological series of alkyl benzoates, including vapor pressures, enthalpies of vaporization, enthalpies of solution, and enthalpies of formation, were the focus of this study. The data sets for each thermodynamic property were evaluated using structure–property correlations and quantum chemical calculations and recommended for thermochemical calculations. The energetics of chemical reactions based on alkyl benzoates relevant to hydrogen storage were calculated and compared to the reaction enthalpies of common liquid organic hydrogen carriers. Benzoates ; Chemistry ; Alkyl ; Organic chemistry ; Vaporization ; Thermodynamics ; Benzoic acid ; Yield (engineering) ; Computational chemistry Chemical Thermodynamics and Molecular Structure ; Free Radicals and Antioxidants ; Chemistry and Chemical Engineering
Authors: Mingyu Luo | Ruo-gu Xu | Ying Shi | Yu-zuo Wang | Feng Li
Source: New Carbon Materials (article, 2023-04-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Graphene with KI-modified pore structure and its electrochemical capacitors application Materials science ; Graphene ; Capacitance ; Chemical engineering ; Electrolyte ; Electrochemistry ; Supercapacitor ; Ionic liquid ; Porosity ; Oxide ; Composite material ; Nanotechnology ; Electrode ; Organic chemistry ; Metallurgy ; Catalysis Supercapacitor Materials and Fabrication ; Advancements in Battery Materials ; Advanced Battery Materials and Technologies
Authors: Pragati Shukla | Madan D. Ambhore | Venkataramanarao G. Anand
Source: Chemistry - A European Journal (article, 2023-02-09)
Field: Materials Science — Materials Chemistry

Redox Assisted Reversible Aromaticity Transition Between 30π Hückel and 28π Möbius Dication of a Core‐Modified Isophlorinoid The electronic properties of a hexaphyrin was fine-tuned via core-modification leading to the formation of a Hückel aromatic 30π hexaphyrin which incorporates two pyrrole and four furan rings in the π-conjugated pathway. This Hückel aromatic hexaphyrin modified its conformation upon two-electron ring oxidation either with triflic acid or Meerwein salt [Et<sub>3</sub> O]<sup>+</sup> [SbCl<sub>6</sub> ]<sup>-</sup> to yield 28π Möbius aromatic dication species. Reversible aromatic transition was established by spectroscopic techniques and further supported by quantum chemical calculations. Dication ; Aromaticity ; Chemistry ; Pyrrole ; Ring (chemistry) ; Furan ; Antiaromaticity ; Redox ; Photochemistry ; Conjugated system ; Triflic acid ; Organic chemistry ; Molecule Porphyrin and Phthalocyanine Chemistry ; Synthesis and Properties of Aromatic Compounds ; Photochromic and Fluorescence Chemistry
Authors: Yujia Wang | Wenjie Song | Lijun Bao | Junwu Wei | Yangyang Qian | Yunmei Bi
Source: RSC Advances (article, 2023-01-01)
Field: Materials Science — Polymers and Plastics

Enzyme and pH dual responsive linear-dendritic block copolymer micelles based on a phenylalanyl–lysine motif and peripherally ketal-functionalized dendron as potential drug carriers Stimuli-responsive linear-dendritic block copolymers (LDBCs) have attracted significant research attention as novel drug carriers. We report here three generations of new enzyme and pH dual responsive linear-dendritic block copolymers (LDBCs) with a phenylalanyl-lysine (Phe-Lys) dipeptide linking hydrophilic linear poly(<i>N</i>-vinylpyrrolidone) (PNVP) and a hydrophobic peripherally ketal-functionalized dendron derived from 2,2'-bis(hydroxymethyl)propionic acid (bis-MPA). The LDBCs are synthesized <i>via</i> a combination of interchange of xanthates/reversible addition-fragmentation chain transfer (MADIX/RAFT) polymerization of <i>N</i>-vinylpyrrolidone (NVP) and "chain-first" strategy. Their structures are confirmed by <sup>1</sup>H NMR spectra. The gel permeation chromatograph (GPC) analysis revealed that the LDBCs have a narrow molecular weight distribution (PDI ≤ 1.25). The amphiphilic LDBCs can self-assemble into spherical nanomicelles in aqueous solution. The presence of enzyme or/and the change of pH cause disassembly of micelles to release encapsulated cargos. The release rates of the guest molecules are faster in buffer solution at pH 5.0 than those upon the addition of the activating enzyme and can be fine-tuned by changing the generation of bis-MPA dendrons. The combination of enzyme and pH dual stimuli results in significantly accelerated and more complete release of the loaded hydrophobic guests. The cell viability assay confirmed the favorable biocompatibility until the LDBC micelle concentration reached 800 μg mL<sup>-1</sup>. These results indicate that the LDBCs can be considered as a good candidate for targeting drug delivery. Dipeptide ; Dendrimer ; Micelle ; Copolymer ; Amphiphile ; Biocompatibility ; Chemistry ; Drug carrier ; Enzyme ; Combinatorial chemistry ; Drug ; Drug delivery ; Stereochemistry ; Polymer chemistry ; Organic chemistry ; Biochemistry ; Peptide ; Polymer ; Pharmacology ; Medicine Dendrimers and Hyperbranched Polymers ; Chemical Synthesis and Analysis ; Advanced Polymer Synthesis and Characterization
Authors: Anna Lucia Pellegrino | Emil Milan | Adolfo Speghini | Graziella Malandrino
Source: Materials (article, 2023-10-27)
Field: Chemistry — Inorganic Chemistry

Fabrication of Europium-Doped CaF2 Films via Sol-Gel Synthesis as Down-Shifting Layers for Solar Cell Applications In the present work, an in-depth study on the sol-gel process for the fabrication of Eu-doped CaF<sub>2</sub> materials in the form of thin films has been addressed for the production of down-shifting layers. Fine-tuning of the operative parameters, such as the annealing temperature, substrate nature and doping ion percentage, has been finalized in order to obtain Eu(III)-doped CaF<sub>2</sub> thin films via a reproducible and selective solution process for down-shifting applications. An accurate balance of such parameters allows for obtaining films with high uniformity in terms of both their structural and compositional features. The starting point of the synthesis is the use of a mixture of Ca(hfa)<sub>2</sub>•diglyme•H<sub>2</sub>O and Eu(hfa)<sub>3</sub>•diglyme adducts, with a suited ratio to produce 5%, 10% and 15% Eu-doped CaF<sub>2</sub> films, in a water/ethanol solution. A full investigation of the structural, morphological and compositional features of the films, inspected using X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray analysis (EDX), respectively, has stated a correlation between the annealing temperature and the structural characteristics and morphology of the CaF<sub>2</sub> thin films. Interestingly, crystalline CaF<sub>2</sub> films are obtained at quite low temperatures of 350-400 °C. The down-shifting properties, validated by taking luminescence measurements under UV excitation, have allowed us to correlate the local environment in terms of the degree of symmetry around the europium ions with the relative doping ion percentages. Europium ; Doping ; Materials science ; Annealing (glass) ; Thin film ; Luminescence ; Analytical Chemistry (journal) ; Sol-gel ; Phosphor ; Diglyme ; Fabrication ; Chemical engineering ; Mineralogy ; Nanotechnology ; Optoelectronics ; Chemistry ; Composite material ; Organic chemistry Inorganic Fluorides and Related Compounds ; Luminescence Properties of Advanced Materials ; Microwave Dielectric Ceramics Synthesis
Authors: Laurenz Thyen | Daniel Splith | Max Kneiß | Marius Grundmann | Holger von Wenckstern
Source: Journal of Vacuum Science & Technology A Vacuum Surfaces and Films (article, 2023-01-26)
Field: Materials Science — Materials Chemistry

Masked-assisted radial-segmented target pulsed-laser deposition: A novel method for area-selective deposition using pulsed-laser deposition We introduce a novel technique, masked-assisted radial-segmented target pulsed-laser deposition (MARS-PLD) for unprecedented capabilities in area-selective physical vapor deposition. The MARS-PLD setup consists of a conventional PLD chamber with mechanical feedthrough for a laterally movable mask or mask set. By this means and, in principle, the arbitrary choice of a shadow mask layout, any desired area on a substrate can be masked in order to create multinary lateral and vertical material composition gradients using radially segmented targets already described in the literature [Kneiß et al., ACS Comb. Sci. 20, 643–652 (2018)]. To illustrate the capabilities of this method, we fabricated material gradients in (Mg,Zn)O thin films with a nearly linear spatial variation of the cation composition of 15at.%mm−1. Additionally, we fine-tuned our setup to fabricate a material gradient on a predefined two-dimensional lateral pattern to demonstrate the versatile capabilities of the MARS-PLD technique. Pulsed laser deposition ; Materials science ; Deposition (geology) ; Mars Exploration Program ; Shadow mask ; Substrate (aquarium) ; Laser ; Feedthrough ; Thin film ; Optoelectronics ; Optics ; Nanotechnology ; Physics ; Geology Electronic and Structural Properties of Oxides ; ZnO doping and properties ; Semiconductor materials and devices
Authors: Alison Sy-min Chang | Melanie A. Kascoutas | Quinn Valentine | Kiera How | Rachel Thomas | Amanda K. Cook
Source: ChemRxiv (preprint, 2023-09-21)
Field: Chemistry — Inorganic Chemistry

Alkene Isomerization using a Heterogeneous Nickel-Hydride Catalyst Transition metal-catalyzed alkene isomerization is an enabling technology used to install an alkene distal to its original site. Due to their well-defined structure, homogeneous catalysts can be fine-tuned to optimize reactivity, stereoselectivity, and positional selectivity, but they often suffer from instability and non-recyclability. Heterogeneous catalysts are generally highly robust, but they continue to lack active-site specificity and are challenging to rationally improve through structural modification, therefore exhibiting lower catalytic performance. Known single-site heterogeneous catalysts for alkene isomerization utilize precious metals and bespoke, expensive, and synthetically intense supports. Additionally, they generally have mediocre reactivity, inspiring us to develop a heterogeneous catalyst with an active site made from readily available compounds made of Earth-abundant elements. Previous work demonstrated that a very active homoge-neous catalyst is formed upon protonation of Ni[P(OEt)3]4 by H2SO4, generating a [Ni–H]+ active site. This catalyst is in-credibly active, but also decomposes readily, which severely limits its utility. Herein we show that by using a solid acid (sulfated zirconia, SZO300), not only is this decomposition prevented, but high activity is maintained, improved selectivity is achieved, and a broader scope of functional groups is tolerated. Preliminary mechanistic experiments suggest that the catalyst likely goes through an intermolecular, two-electron pathway. A detailed kinetic study comparing the state-of-the-art Ni and Pd isomerization catalysts reveals that the highest activity and selectivity is seen with the Ni/SZO300 system. The reactivity of Ni/SZO300, is not limited to alkene isomerization; it is also a competent catalyst for hydroalkenylation, hydroboration, and hydrosilylation, demonstrating the broad application of this heterogeneous catalyst. Isomerization ; Alkene ; Catalysis ; Chemistry ; Reactivity (psychology) ; Selectivity ; Heterogeneous catalysis ; Combinatorial chemistry ; Photochemistry ; Protonation ; Organic chemistry Asymmetric Hydrogenation and Catalysis ; Catalytic Cross-Coupling Reactions ; Organometallic Complex Synthesis and Catalysis
Authors: Danni Li | Yeyang Ma | Wencheng Xia | Youqi Tao | Shujun Zhang | Hong Zhang | Dan Li | Bin Dai | Cong Liu
Source: Angewandte Chemie International Edition (article, 2023-08-31)
Field: Materials Science — Biomaterials

Creating an Amyloid ‘Kaleidoscope’ Using Short Iodinated Peptides Amyloid fibrils formed by peptides with different sequences exhibit diversified morphologies, material properties and activities, making them valuable for developing functional bionanomaterials. However, the molecular understanding underlying the structural diversity of peptide fibrillar assembly at atomic level is still lacking. In this study, by using cryogenic electron microscopy, we first revealed the structural basis underlying the highly reversible assembly of <sup>1</sup> GFGGNDNFG<sup>9</sup> (referred to as hnRAC1) peptide fibril. Furthermore, by installing iodine at different sites of hnRAC1, we generated a collection of peptide fibrils with distinct thermostability. By determining the atomic structures of the iodinated fibrils, we discovered that iodination at different sites of the peptide facilitates the formation of diverse halogen bonds and triggers the assembly of entirely different structures of iodinated fibrils. Finally, based on this structural knowledge, we designed an iodinated peptide that assembles into new atomic structures of fibrils, exhibiting superior thermostability, that aligned with our design. Our work provides an in-depth understanding of the atomic-level processes underlying the formation of diverse peptide fibril structures, and paves the way for creating an amyloid "kaleidoscope" by employing various modifications and peptide sequences to fine-tune the atomic structure and properties of fibrillar nanostructures. Kaleidoscope ; Amyloid (mycology) ; β amyloid ; Medicine ; Chemistry ; Internal medicine ; Art ; Alzheimer's disease ; Pathology ; Visual arts Supramolecular Self-Assembly in Materials ; Alzheimer's disease research and treatments ; Chemical Synthesis and Analysis
Authors: Katalin Czifrák | Csilla Lakatos | Gabriella P. Szabó | Bence Vadkerti | Lajos Daróczi | Miklós Zsuga | Sándor Kéki
Source: Polymers (article, 2023-07-03)
Field: Materials Science — Polymers and Plastics

Bisphenol A Diglycidyl Ether-Primary Amine Cooligomer-poly(ε-caprolactone) Networks: Synthesis and Characterization In this work, the preparation and systematic investigation of cross-linked polyurethane-epoxy (PU-EP) polymer systems are reported. The PU-EP polymers were prepared using a reaction of isocyanate (NCO)-terminated PU-prepolymer with diglycidyl ether of bisphenol A (DGEBA)-amine cooligomer. The oligomerization of DGEBA was carried out by adding furfurylamine (FA) or ethanolamine (EA), resulting in DGEBA-amine cooligomers. For the synthesis of NCO-terminated PU-prepolymer, poly(ε-caprolactone)diol (PCD) (M<sub>n</sub> = 2 kg/mol) and 1,6-hexamethylene diisocyanate (HDI) were used. The cross-linking was achieved by adding DGEBA-amine cooligomer to PU-prepolymer, in which the obtained urethane bonds, due to the presence of free hydroxil groups in the activated DGEBA, served as netpoints. During cross-linking, ethanolamine provides an additional free hydroxyl group for the formation of a new urethane bond, while furfurylamine can serve as a thermoreversible coupling element (e.g., Diels-Alder adduct). The PU-EP networks were characterized using attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), dynamical mechanical analysis (DMA) and scanning electron microscopy (SEM). The DMA curves of some PU-EPs (depending on the compositions and the synthetic method) revealed a plateau-like region above the melting temperature (T<sub>m</sub>) of PCD, confirming the presence of a cross-linked structure. This property resulted in a shape memory (SM) behavior for these samples, which can be fine-tuned in the presence of furfurylamine through the formation of additional thermoreversible bonds (e.g., Diels-Alder adduct). Prepolymer ; Polymer chemistry ; Diglycidyl ether ; Isocyanate ; Polyurethane ; Materials science ; Differential scanning calorimetry ; Caprolactone ; Bisphenol A ; Epoxy ; Polymer ; Copolymer Polymer composites and self-healing ; Synthesis and properties of polymers ; Carbon dioxide utilization in catalysis
Authors: Souhardya Bera | Shibsankar Mondal | A.K. Majumder | Swastik Paul | Ridipt Mishra | Subhasis Roy
Source: Chemistry of Inorganic Materials (article, 2023-11-14)
Field: Chemistry — Inorganic Chemistry

A potential roadmap on the development, application, and loopholes of metal-organic frameworks in high-performance third-generation solar cells The third-generation solar cells have found incremental utilization over their last two-generation counterparts for their increased environmental friendliness, facile fabrication, relatively high efficiency, and low cost in commercialization. A coordinated porosity and a high surface area deem Metal-Organic Framework (MOF) an exciting candidate for study in solar cell fabrication. This review article aims to assemble the various MOF structures for developing high-performance solar cell studies. To be understood, MOF was not designed as a single material but has always enhanced efficiency as guest materials or secondary support structures. Pristine MOFs have been studied extensively as photoanodes in Dye-Sensitized Solar Cells (DSSC). However, given their intrinsically insulating nature and dull charge transport mechanism, they limit cell performance and efficiency. The constrained conductivity also limits their replacement as counter electrodes, which require a cheaper and more stable electrocatalyst than platinum. It has been found to provide extra crystallinity to the perovskite layer for Perovskite Solar Cells (PSC), further enhancing device performance and stability. The article presents a detailed report on developing MOF-derived materials for DSSC and PSC components. MOFs with excellent light-harvesting capacity and photosensitizing linkers have also been a curious case of study. Moreover, the crystal framework of MOFs can be designed efficiently, which helps solar cell component fabrication in fine-tuning its properties. Although fabrication from MOFs is still in the primitive stage, this paper provides knowledge in the field of both photovoltaics, and MOF diversification, understands the studies that have already been reported regarding the performance and stability, the enhancement in their properties, and loopholes that remain to be understood and nullified. Fabrication ; Nanotechnology ; Materials science ; Photovoltaics ; Solar cell ; Dye-sensitized solar cell ; Photovoltaic system ; Organic solar cell ; Energy conversion efficiency ; Crystallinity ; Electrode ; Optoelectronics ; Chemistry ; Polymer ; Electrical engineering ; Engineering ; Composite material Metal-Organic Frameworks: Synthesis and Applications ; Perovskite Materials and Applications ; Advanced Photocatalysis Techniques