jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Mohammad Mahdi Sabouri Ghannad | Majid Mohammadi Nia | Saber Moradi
Source: Journal of Building Engineering (article, 2021-06-12)
Field: Materials Science — Materials Chemistry

Predictive equations and continuum FE models for self-centering response of SMA-based steel beam-column connections with steel angles SMA* ; Structural engineering ; Shape-memory alloy ; Beam (structure) ; Finite element method ; Materials science ; Connection (principal bundle) ; Residual ; Sensitivity (control systems) ; Engineering ; Composite material ; Computer science Shape Memory Alloy Transformations ; Structural Behavior of Reinforced Concrete ; Structural Load-Bearing Analysis
Authors: Ping He | Haoda Ruan | Congyang Wang | Hao Lü
Source: Polymers (article, 2021-12-16)
Field: Materials Science — Polymers and Plastics

Mechanical Properties and Thermal Conductivity of Thermal Insulation Board Containing Recycled Thermosetting Polyurethane and Thermoplastic This study used a mechanochemical method to analyze the recycling mechanism of polyurethane foam and optimize the recycling process. The use of mechanochemical methods to regenerate the polyurethane foam powder breaks the C-O bond of the polyurethane foam and greatly enhances the activity of the powder. Based on orthogonal test design, the mesh, proportion, temperature, and time were selected to produce nine recycled boards by heat pressing. Then, the influence of four factors on the thermal conductivity and tensile strength of the recycled board was analyzed. The results show that 120 mesh polyurethane foam powder has strong activity, and the tensile strength can reach 9.913 Mpa when it is formed at 205 °C and 40 min with 50% PP powder. With the help of the low thermal conductivity of the polyurethane foam, the thermal conductivity of the recycled board can reach 0.037 W/m·K at the parameter of 40 mesh, 80%, 185 °C, 30 min. This research provides an effective method for the recycling of polyurethane foam. Polyurethane ; Materials science ; Composite material ; Thermosetting polymer ; Thermal conductivity ; Ultimate tensile strength ; Thermoplastic polyurethane ; Thermal insulation ; Pressing ; Elastomer Polymer composites and self-healing ; Flame retardant materials and properties ; Electrospun Nanofibers in Biomedical Applications
Authors: Joel F. Destino | Erin M. Gross | Emily D. Niemeyer | Steven C. Petrovic
Source: Analytical and Bioanalytical Chemistry (article, 2021-01-09)
Field: Chemistry — Physical and Theoretical Chemistry

Hands-on experiences for remotely taught analytical chemistry laboratories Medical laboratory ; Analytical Chemistry (journal) ; Engineering ; Chemistry ; Environmental chemistry ; Medicine Various Chemistry Research Topics ; Experimental Learning in Engineering ; Innovative Teaching Methods
Authors: Siqiang Fang | Jian‐Ping Tan | Jianke Pan | Hongkui Zhang | Yuan Chen | Xiaoyu Ren | Tianli Wang
Source: Angewandte Chemie (article, 2021-03-17)
Field: Chemistry — Organic Chemistry

Enantiodivergent Kinetic Resolution of 1,1′‐Biaryl‐2,2′‐Diols and Amino Alcohols by Dipeptide‐Phosphonium Salt Catalysis Inspired by the Atherton–Todd Reaction Abstract A highly enantiodivergent organocatalytic method is disclosed for the synthesis of atropisomeric biaryls via kinetic resolution inspired by a dipeptide‐phosphonium salt‐catalyzed Atherton–Todd (A‐T) reaction. This flexible approach led to both R ‐ and S ‐enantiomers by fine‐tuning of bifunctional phosphonium with excellent selectivity factors ( s ) of up to 1057 and 525, respectively. The potential of newly synthesized O‐phosphorylated biaryl diols was illustrated by the synthesis of axially chiral organophosphorus compounds. Mechanistic investigations suggest that the bifunctional phosphonium halide catalyst differentiates between the in‐situ‐generated P‐species in the A‐T process, mainly involving phosphoryl chloride and phosphoric anhydride, thus leading to highly enantiodivergent O‐phosphorylation reactions. Furthermore hydrogen bonding interactions between the catalysts and phosphorus molecules were crucial in asymmetric induction. Phosphonium ; Chemistry ; Kinetic resolution ; Bifunctional ; Dipeptide ; Phosphonium salt ; Catalysis ; Enantiomer ; Combinatorial chemistry ; Enantioselective synthesis ; Selectivity ; Pyridinium ; Organic chemistry ; Peptide Axial and Atropisomeric Chirality Synthesis ; Molecular spectroscopy and chirality ; Chemical synthesis and alkaloids
Authors: David Babuka | Kristýna Kolouchová | Lenka Loukotová | Ondřej Sedláček | Ondřej Groborz | Aneta Škarková | Alexander Zhigunov | Ewa Pavlová | Richard Hoogenboom | Martin Hrubý | Petr Štěpánek
Source: Macromolecules (article, 2021-12-02)
Field: Chemistry — Organic Chemistry

Self-Assembly, Drug Encapsulation, and Cellular Uptake of Block and Gradient Copolymers of 2-Methyl-2-oxazine and 2-<i>n</i>-Propyl/butyl-2-oxazoline Self-assembled amphiphilic polymers have been extensively studied for various biomedical applications, as they show advantageous properties for diagnosis and therapy. In this work, we extensively compared amphiphilic copolymers of the hydrophilic monomer 2-methyl-2-oxazine (MeOzi) and the thermoresponsive or hydrophobic monomers 2-propyl-2-oxazoline (PrOx) or 2-butyl-2-oxazoline (BuOx) in both block and gradient monomer distributions. Such a head-to-head comparison between block and gradient copolymers, which has thus far been mostly missing in the available literature, should provide important insight into the differences and similarities between these two architectures. We investigated the properties of our polymers using a wide array of analytical methods, including dynamic light scattering (DLS), small-angle neutron (SANS) and X-ray scattering (SAXS), one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy, transmission electron microscopy (TEM), drug loading (DL), cellular uptake, and cytotoxicity studies. Most of the studied polymers formed self-assembled nanoparticles, but their properties varied with the monomer ratio, polymer length, and polymer architecture, and these factors could be used to fine-tune the properties of the polymer to meet the demands of the desired application. Both block and gradient copolymers showed similar critical association concentrations and DL properties for the antituberculosis drug rifampicin. Finally, we confirmed that the nanoparticles could be internalized by macrophages, which indicates great potential for the utilization of these nanoparticles in drug delivery. Copolymer ; Amphiphile ; Monomer ; Polymer ; Dynamic light scattering ; Materials science ; Polymer chemistry ; Drug delivery ; Nanoparticle ; Chemical engineering ; Chemistry ; Nanotechnology Advanced Polymer Synthesis and Characterization ; Synthesis and properties of polymers ; Supramolecular Chemistry and Complexes
Authors: Peng Wu | Yu Shen | Hongfeng Li | Wenxiong Shi | Lulu Zhang | Ting Pan | Wen‐Bo Pei | Weina Zhang | Fengwei Huo
Source: Small Structures (article, 2021-02-16)
Field: Chemistry — Inorganic Chemistry

Binding Site Effect in Metal‐Organic Frameworks for Property Regulation of Metal Nanoparticles Metal nanoparticles (MNPs) supported on metal–organic frameworks (MOFs) have exhibited excellent performance in various catalytic reactions. As a class of crystal catalysts, the roles played by MOFs different positions in regulating the MNPs properties are distinct. It is therefore meaningful to clarify the influence of different positions of MOFs on MNPs to help reveal the structure–activity relationship. However, the random dispersion of MNPs in the MOFs matrixes is usually an obstacle existing in the traditional preparation methods. Herein, a facile strategy is developed to precisely control the MNPs growth behavior on the target binding sites of MOFs. The MNPs on edges of MOFs show significantly improved hydrogen evolution reaction performance in comparison to those on the planes of MOFs, mainly because the electronic structure of MNPs is regulated by special interface originating from MNPs growth on the edges of MOFs, which provides high density of unsaturated copper ions. The effect of different binding sites of MOFs on MNPs properties is clarified, which is highly desired for fine‐tuning the structures and properties of the MOF composites. Metal-organic framework ; Nanoparticle ; Metal ; Nanotechnology ; Catalysis ; Materials science ; Dispersion (optics) ; Metal ions in aqueous solution ; Chemical engineering ; Chemistry ; Organic chemistry ; Adsorption Metal-Organic Frameworks: Synthesis and Applications ; Advanced Nanomaterials in Catalysis ; Catalytic Processes in Materials Science
Authors: Hui‐Juan Wang | Heng‐Yi Zhang | Wen‐Wen Xing | Huang Wu | Yongliang Cui | Yu Liu
Source: Chinese Chemical Letters (article, 2021-12-26)
Field: Materials Science — Biomaterials

Photodimerization-induced transition of helixes to vesicles based on coumarin-12-crown-4 Dimer ; Supramolecular chemistry ; Vesicle ; Crystallography ; Chemistry ; Superstructure ; Covalent bond ; Molecule ; Helix (gastropod) ; Stereochemistry ; Crystal structure ; Organic chemistry ; Membrane ; Physics Supramolecular Self-Assembly in Materials ; Photochromic and Fluorescence Chemistry ; Polydiacetylene-based materials and applications
Authors: Daniel Bím | Anastassia N. Alexandrova
Source: Chemical Science (article, 2021-01-01)
Field: Chemistry — Electrochemistry

Electrostatic regulation of blue copper sites In the last 50 years, the blue copper proteins became central targets of investigation. Extensive experiments focused on the Cu coordination to probe the effect of local perturbations on its properties. We found that local electric fields, generated by charged residues evolutionarily placed throughout the protein edifice, mainly second sphere, but also more remotely, constitute an additional significant factor regulating blue copper proteins. These fields are not random, but exhibit a highly specific directionality, negative with respect to the and vectors in the Cu first shell. The field magnitude contributes to fine-tuning of the geometric and electronic properties of Cu sites in individual blue copper proteins. Specifically, the local electric fields evidently control the Cu-S<sub>Met</sub> bond distance, Cu(ii)-S<sub>Cys</sub> bond covalency, and the energies of the frontier molecular orbitals, which, in turn, govern the Cu(ii/i) reduction potential and the relative absorption intensities at 450 nm and 600 nm. Copper ; Chemistry ; Organic chemistry Electrochemical Analysis and Applications ; Molecular Sensors and Ion Detection ; Electrochemical sensors and biosensors
Authors: Maria Lykaki | Sofia Stefa | Sónia A. C. Carabineiro | M.A. Soria | Luı́s M. Madeira | Michalis Konsolakis
Source: Catalysts (article, 2021-06-21)
Field: Materials Science — Materials Chemistry

Shape Effects of Ceria Nanoparticles on the Water‒Gas Shift Performance of CuOx/CeO2 Catalysts The copper–ceria (CuOx/CeO2) system has been extensively investigated in several catalytic processes, given its distinctive properties and considerable low cost compared to noble metal-based catalysts. The fine-tuning of key parameters, e.g., the particle size and shape of individual counterparts, can significantly affect the physicochemical properties and subsequently the catalytic performance of the binary oxide. To this end, the present work focuses on the morphology effects of ceria nanoparticles, i.e., nanopolyhedra (P), nanocubes (C), and nanorods (R), on the water–gas shift (WGS) performance of CuOx/CeO2 catalysts. Various characterization techniques were employed to unveil the effect of shape on the structural, redox and surface properties. According to the acquired results, the support morphology affects to a different extent the reducibility and mobility of oxygen species, following the trend: R &gt; P &gt; C. This consequently influences copper–ceria interactions and the stabilization of partially reduced copper species (Cu+) through the Cu2+/Cu+ and Ce4+/Ce3+ redox cycles. Regarding the WGS performance, bare ceria supports exhibit no activity, while the addition of copper to the different ceria nanostructures alters significantly this behaviour. The CuOx/CeO2 sample of rod-like morphology demonstrates the best catalytic activity and stability, approaching the thermodynamic equilibrium conversion at 350 °C. The greater abundance in loosely bound oxygen species, oxygen vacancies and highly dispersed Cu+ species can be mainly accounted for its superior catalytic performance. Catalysis ; Redox ; Copper ; Oxygen storage ; Chemical engineering ; Nanoparticle ; Water-gas shift reaction ; Nanorod ; Materials science ; Oxygen ; Particle size ; Noble metal ; Particle (ecology) ; Inorganic chemistry ; Nanotechnology ; Chemistry ; Metallurgy Catalytic Processes in Materials Science ; Copper-based nanomaterials and applications ; Nanomaterials for catalytic reactions
Authors: Javier Troyano | Alexandre Legrand | Shuhei Furukawa
Source: Trends in Chemistry (article, 2021-03-01)
Field: Chemistry — Inorganic Chemistry

Mechanoresponsive Porosity in Metal-Organic Frameworks Materials science ; Porosity ; Nanotechnology ; Metastability ; Metal-organic framework ; Metamaterial ; Stress (linguistics) ; Composite material ; Chemistry Metal-Organic Frameworks: Synthesis and Applications ; Nanoplatforms for cancer theranostics ; Magnetism in coordination complexes
Authors: Pabitra Saha | Anand Raj Palanisamy | Marta Santi | Ritabrata Ganguly | Somashree Mondal | Nikhil K. Singha | Andrij Pich
Source: Polymers for Advanced Technologies (article, 2021-01-26)
Field: Materials Science — Surfaces, Coatings and Films

Thermoresponsive zwitterionic poly(phosphobetaine) microgels: Effect of <scp>macro‐RAFT</scp> chain length and cross‐linker molecular weight on their antifouling properties Abstract Adsorption of proteins on biological surfaces is a detrimental phenomenon that reduces the work‐life of the implants in various biomedical applications. Here, we synthesized a new class of thermoresponsive zwitterionic poly(phosphobetaine) (PMPC) microgel with excellent surface antifouling property by macro‐RAFT mediated thiol‐epoxy click reaction. End‐group modified zwitterionic PMPC homopolymers with well‐defined molecular weight and narrow dispersity were grafted onto poly( N ‐vinylcaprolactam‐ co ‐glycidyl methacrylate) (PVG) copolymer backbone followed by addition of a cross‐linker, leading to microgel formation. While no upper critical solution temperature (UCST) was found in poly( N ‐vinylcaprolactam‐ co ‐glycidyl methacrylate‐ g ‐2‐methacryloyloxyethyl phosphorylcholine) (PVGP) graft copolymers, the corresponding microgels exhibited both UCST and lower critical solution temperature (LCST) transitions, related to the swelling and collapse of PMPC and poly ( N ‐vinylcaprolactam) (PVCL) components respectively. An increase in the molecular chain length of the PMPC increased the shifting of UCST and LCST of the microgels to higher temperatures, due to the ability of zwitterionic groups to coordinate a large number of water molecules. The effect of the variation in the molecular weights of amphiphilic poly(ethylene glycol) diamine (PEG‐NH 2 ) cross‐linker was also reflected in both temperature and salt responsiveness of the microgels. The efficacy of the microgels as potential antifouling materials was further studied by fluorescence microscopy and XPS analysis on microgel coatings treated with FITC‐BSA solution and pure BSA solution respectively. Lower protein adsorption was observed for microgels grafted with higher molecular chain length of PMPC, whereas, the microgels synthesized using higher molecular weight PEG‐NH 2 diamine cross‐linker displayed greater protein adsorption on their surfaces. Lower critical solution temperature ; Upper critical solution temperature ; Materials science ; Polymer chemistry ; Methacrylate ; Copolymer ; Ethylene glycol ; Glycidyl methacrylate ; Dispersity ; PEG ratio ; Chemical engineering ; Polymer Polymer Surface Interaction Studies ; Hydrogels: synthesis, properties, applications ; Advanced Polymer Synthesis and Characterization
Authors: Simon Stuij | Joep Rouwhorst | H. J. Jonas | Nicola Ruffino | Zhe Gong | Stefanno Sacanna | Peter G. Bolhuis | Peter Schall
Source: Physical Review Letters (article, 2021-08-30)
Field: Materials Science — Materials Chemistry

Revealing Polymerization Kinetics with Colloidal Dipatch Particles Limited-valency colloidal particles can self-assemble into polymeric structures analogous to molecules. While their structural equilibrium properties have attracted wide attention, insight into their dynamics has proven challenging. Here, we investigate the polymerization dynamics of semiflexible polymers in 2D by direct observation of assembling divalent particles, bonded by critical Casimir forces. The reversible critical Casimir force creates living polymerization conditions with tunable chain dissociation, association, and bending rigidity. We find that unlike dilute polymers that show exponential size distributions in excellent agreement with Flory theory, concentrated samples exhibit arrest of rotational and translational diffusion due to a continuous isotropic-to-nematic transition in 2D, slowing down the growth kinetics. These effects are circumvented by the addition of higher-valency particles, cross linking the polymers into networks. Our results connecting polymer flexibility, polymer interactions, and the peculiar isotropic-nematic transition in 2D offer insight into the polymerization processes of synthetic two-dimensional polymers and biopolymers at membranes and interfaces. Polymerization ; Materials science ; Polymer ; Chemical physics ; Liquid crystal ; Kinetics ; Colloid ; Chemistry ; Physical chemistry ; Classical mechanics ; Physics ; Composite material Pickering emulsions and particle stabilization ; Material Dynamics and Properties ; Lipid Membrane Structure and Behavior
Authors: Marianna V. Kharlamova | Christian Kramberger
Source: Nanomaterials (article, 2021-10-09)
Field: Materials Science — Materials Chemistry

Metal Cluster Size-Dependent Activation Energies of Growth of Single-Chirality Single-Walled Carbon Nanotubes inside Metallocene-Filled Single-Walled Carbon Nanotubes By combining in situ annealing and Raman spectroscopy measurements, the growth dynamics of nine individual-chirality inner tubes (8,8), (12,3), (13,1), (9,6), (10,4), (11,2), (11,1), (9,3) and (9,2) with diameters from ~0.8 to 1.1 nm are monitored using a time resolution of several minutes. The growth mechanism of inner tubes implies two successive stages of the growth on the carburized and purely metallic catalytic particles, respectively, which are formed as a result of the thermally induced decomposition of metallocenes inside the outer SWCNTs. The activation energies of the growth on carburized Ni and Co catalytic particles amount to 1.85-2.57 eV and 1.80-2.71 eV, respectively. They decrease monotonically as the tube diameter decreases, independent of the metal type. The activation energies of the growth on purely metallic Ni and Co particles equal 1.49-1.91 eV and 0.77-1.79 eV, respectively. They increase as the tube diameter decreases. The activation energies of the growth of large-diameter tubes (<i>d<sub>t</sub></i> = ~0.95-1.10 nm) on Ni catalyst are significantly larger than on Co catalyst, whereas the values of small-diameter tubes (<i>d<sub>t</sub></i> = ~0.80-0.95 nm) are similar. For both metals, no dependence of the activation energies on the chirality of inner tubes is observed. Materials science ; Metal ; Carbon nanotube ; Catalysis ; Raman spectroscopy ; Chirality (physics) ; Annealing (glass) ; Activation energy ; Metallocene ; Analytical Chemistry (journal) ; Nanotechnology ; Composite material ; Physical chemistry ; Chemistry ; Metallurgy ; Polymerization ; Organic chemistry ; Chiral symmetry Carbon Nanotubes in Composites ; Graphene research and applications ; Advancements in Battery Materials
Authors: Mari C. Mañas‐Torres | Gloria B. Ramírez‐Rodríguez | José I. García-Peiro | Belén Parra‐Torrejón | Juan M. Cuerva | Modesto T. López‐López | Luı́s Álvarez de Cienfuegos | José Manuel Delgado‐López
Source: Inorganic Chemistry Frontiers (article, 2021-12-17)
Field: Materials Science — Biomaterials

Organic/inorganic hydrogels by simultaneous self-assembly and mineralization of aromatic short-peptides Hybrid hydrogels with a tunable structure–function relationship were prepared by simultaneous self-assembly and mineralization of aromatic short-peptides. Sub-stoichiometric Ca concentrations resulted in nanoapatite oriented along the peptide fiber. Self-healing hydrogels ; Mineralization (soil science) ; Stoichiometry ; Chemistry ; Peptide ; Self-assembly ; Self-assembling peptide ; Chemical engineering ; Polymer chemistry ; Organic chemistry ; Biochemistry ; Nitrogen Supramolecular Self-Assembly in Materials ; Cephalopods and Marine Biology ; Polydiacetylene-based materials and applications
Authors: Jesús G. Ovejero | Federico Spizzo | M. P. Morales | L. Del Bianco
Source: Materials (review, 2021-10-26)
Field: Materials Science — Biomaterials

Nanoparticles for Magnetic Heating: When Two (or More) Is Better Than One The increasing use of magnetic nanoparticles as heating agents in biomedicine is driven by their proven utility in hyperthermia therapeutic treatments and heat-triggered drug delivery methods. The growing demand of efficient and versatile nanoheaters has prompted the creation of novel types of magnetic nanoparticle systems exploiting the magnetic interaction (exchange or dipolar in nature) between two or more constituent magnetic elements (magnetic phases, primary nanoparticles) to enhance and tune the heating power. This process occurred in parallel with the progress in the methods for the chemical synthesis of nanostructures and in the comprehension of magnetic phenomena at the nanoscale. Therefore, complex magnetic architectures have been realized that we classify as: (a) core/shell nanoparticles; (b) multicore nanoparticles; (c) linear aggregates; (d) hybrid systems; (e) mixed nanoparticle systems. After a general introduction to the magnetic heating phenomenology, we illustrate the different classes of nanoparticle systems and the strategic novelty they represent. We review some of the research works that have significantly contributed to clarify the relationship between the compositional and structural properties, as determined by the synthetic process, the magnetic properties and the heating mechanism. Magnetic nanoparticles ; Nanoparticle ; Materials science ; Nanotechnology ; Magnetic hyperthermia ; Nanostructure ; Drug delivery Nanoparticle-Based Drug Delivery ; Characterization and Applications of Magnetic Nanoparticles ; Magnetic properties of thin films
Authors: Túlio Honório | Maroua Maaroufi | Sirine Al Dandachli | Alexandra Bourdot
Source: Cement and Concrete Research (article, 2021-09-08)
Field: Materials Science — Biomaterials

Ettringite hysteresis under sorption from molecular simulations Ettringite ; Sorption ; Desorption ; Hysteresis ; Relative humidity ; Materials science ; Thermodynamics ; Chemical engineering ; Chemistry ; Composite material ; Adsorption ; Physical chemistry ; Portland cement Clay minerals and soil interactions ; Soil and Unsaturated Flow ; Groundwater and Isotope Geochemistry