jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Sebastian Ulrich | Xiaopu Wang | Markus Rottmar | René M. Rossi | Bradley J. Nelson | Nico Bruns | Ralph Müller | Katharina Maniura‐Weber | Xiao‐Hua Qin | Luciano F. Boesel
Source: ChemRxiv (preprint, 2020-09-01)
Field: Materials Science — Materials Chemistry

Nano-3D-printed Photochromic Objects A new class of photoresist is described for direct laser writing of photoswitchable 3D microstructures. The material comprising off-stoichiometric thiol-ene photo-clickable resins enables rapid two-photon laser processing of highly complex structures and facile post-modification with photoswitches. The microstructures were functionalized with a series of donor-acceptor Stenhouse adducts (DASAs) photoswitches with different excitation wavelength. The versatility of thiol–ene photo-click reaction enabled fine-tuning of the network structure and physical properties as well as the type and concentration of DASA photoswitches. When exposed to visible light, these microstructures exhibit excellent photo-responsiveness and undergo reversible color-changing via photoisomerization of DASA moieties. We describe that the weak fluorescence of DASAs can be used as a reporter of photoswitching, color changes, and thermal recovery, allowing the reading of DASA-containing sub-micrometric structures in 3D. This work delivers a new approach for custom microfabrication of 3D photochromic objects with molecularly engineered color and responsiveness. Photochromism ; Materials science ; Fluorescence ; Photoresist ; Nanotechnology ; Microfabrication ; Photoisomerization ; Photochemistry ; Isomerization ; Chemistry ; Optics ; Fabrication ; Organic chemistry ; Catalysis Photochromic and Fluorescence Chemistry ; Polydiacetylene-based materials and applications ; Nanoplatforms for cancer theranostics
Authors: S.E. Ulrich | Xiaopu Wang | Markus Rottmar | René M. Rossi | Bradley J. Nelson | Nico Bruns | Ralph Müller | Katharina Maniura‐Weber | Xiao‐Hua Qin | Luciano F. Boesel
Source: ChemRxiv (preprint, 2020-09-01)
Field: Materials Science — Materials Chemistry

Nano-3D-printed Photochromic Objects A new class of photoresist is described for direct laser writing of photoswitchable 3D microstructures. The material comprising off-stoichiometric thiol-ene photo-clickable resins enables rapid two-photon laser processing of highly complex structures and facile post-modification with photoswitches. The microstructures were functionalized with a series of donor-acceptor Stenhouse adducts (DASAs) photoswitches with different excitation wavelength. The versatility of thiol–ene photo-click reaction enabled fine-tuning of the network structure and physical properties as well as the type and concentration of DASA photoswitches. When exposed to visible light, these microstructures exhibit excellent photo-responsiveness and undergo reversible color-changing via photoisomerization of DASA moieties. We describe that the weak fluorescence of DASAs can be used as a reporter of photoswitching, color changes, and thermal recovery, allowing the reading of DASA-containing sub-micrometric structures in 3D. This work delivers a new approach for custom microfabrication of 3D photochromic objects with molecularly engineered color and responsiveness. Photochromism ; Materials science ; Photoresist ; Microfabrication ; Nanotechnology ; Fluorescence ; Photoisomerization ; Photochemistry ; Optoelectronics ; Isomerization ; Optics ; Chemistry ; Fabrication ; Organic chemistry ; Catalysis Photochromic and Fluorescence Chemistry ; Polydiacetylene-based materials and applications ; Nanoplatforms for cancer theranostics
Authors: Ioannis Petsagkourakis | Sergi Riera‐Galindo | Tero‐Petri Ruoko | Xenofon Strakosas | Eleni Pavlopoulou | Xianjie Liu | Slawomir Braun | Nara Kim | Samuel Lienemann | Viktor Gueskine | Georges Hadziioannou | Magnus Berggren | Mats Fahlman | Simone Fabiano | Klas Tybrandt | Xavier Crispin
Source: Research Square (preprint, 2020-07-14)
Field: Materials Science — Materials Chemistry

Ultra-High Performance Organic Thermoelectric Generators through Interfacial Doping Gradients Thermoelectric effect ; Doping ; Materials science ; Optoelectronics ; Thermoelectric materials ; Engineering physics ; Nanotechnology ; Physics ; Thermodynamics Advanced Thermoelectric Materials and Devices ; Organic Electronics and Photovoltaics ; Molecular Junctions and Nanostructures
Authors: Timothy J. Hubin
Source:  (preprint, 2020-03-30)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Electronic structure and oxidation catalysis of phenol pendant armed cross-bridged tetraazamacrocycle transition metal complexes We have previously presented synthetic pathways to cross-bridged tetraazamacrocycles with a single phenolic pendant arm. The pendant arm was intended to modify the electronic properties of the transition metal complexes formed, with respect to the parent cross-bridged ligand complexes. These complexes can be used as oxidation catalysts, so control of their electronic properties should allow fine tuning of reactivity in this realm. We present a detailed study of the electronic properties of the phenol-bearing complexes in comparison to published cross-bridged ligand complex analogues. Cyclic voltammetry and UV-Visible spectroscopy were used to investigate how the addition of the phenolic pendant arm modified those electronic properties. We also have obtained initial screening data in hydrogen atom abstraction screening reactions for some complexes, which will be correlated with the electronic properties presented. Transition metal ; Phenol ; Catalysis ; Chemistry ; Metal ; Polymer chemistry ; Photochemistry ; Organic chemistry Magnetism in coordination complexes ; Metal complexes synthesis and properties ; Lanthanide and Transition Metal Complexes
Authors: Xiaoli Wang | Xingfa Gao
Source: The Journal of Physical Chemistry (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

Substituent Effects on Electronic Structures and Peroxidase-Mimicking Activities of Graphyne and Palladium-Doped Graphyne: A Computational Study The substituent effects on the electronic structures and peroxidase-mimicking activities of γ-graphyne (GY) and Pd-doped GY are studied by density functional theory calculations. Both the inductive and mesomeric effects of the substituents significantly influence the electronic structures of GY and its derivatives. However, the complexation strength between Pd atoms and GY is mainly affected by the long-range mesomeric effect rather than the short-range inductive effect of the substituents. The pristine GY hardly has peroxidase-mimicking activity because H₂O₂ molecules strongly chemisorb on the triple bonds in the form of hydroxyl groups. However, GY doped with Pd atoms, namely, Pd@GY, has greatly enhanced peroxidase-mimicking activity. The activity can be further tuned by decorating Pd@GY with external functional groups. The decorated groups alter not only the rate-limiting reaction steps of the catalysis but also the energies associated with the reactions. Pd@GY decorated with F atoms may have the largest peroxidase-mimicking activity among that of the substituents studied here. The results provide an in-depth understanding of the substituent effects on the electronic structures of GY and Pd@GY and suggest the potential of chemical functionalization in fine-tuning the peroxidase-mimicking activities of the materials. Chemistry ; Substituent ; Graphyne ; Density functional theory ; Peroxidase ; Palladium ; Electronic effect ; Catalysis ; Molecule ; Photochemistry ; Computational chemistry ; Stereochemistry ; Enzyme ; Organic chemistry Advanced Nanomaterials in Catalysis ; Nanoplatforms for cancer theranostics ; Graphene and Nanomaterials Applications
Authors: Niranjan Meher | Anil P. Bidkar | Siddhartha Sankar Ghosh | Parameswar Krishnan
Source: SSRN Electronic Journal (article, 2020-01-01)
Field: Materials Science — Materials Chemistry

A Conformational Tweak for Enhanced Cellular Internalization, Photobleaching Resistance and Prolonged Imaging Efficacy Internalization ; Photobleaching ; Resistance (ecology) ; Biophysics ; Chemistry ; Medicine ; Internal medicine ; Biology ; Receptor Luminescence and Fluorescent Materials ; Polydiacetylene-based materials and applications ; Supramolecular Chemistry and Complexes
Authors: Tanay Kundu | Bhuvan B. Shah | Linius Bolinois | Dan Zhao
Source:  (article, 2020-06-09)
Field: Chemistry — Inorganic Chemistry

Functionalization-Induced Breathing Control in Metal-Organic Frameworks for Methane Storage with High Deliverable Capacity Metal–organic frameworks (MOFs) that can undergo structural flexibility upon gas sorption cycle bear enormous potential particularly as adsorbents for methane storage. A molecular level control over such flexibility can be advantageous for the development of smart adsorbents with increased deliverable capacity. Herein, we report the flexible and stable MIL-53(Al) type MOFs, whose breathing behavior can be controlled by systematic installation of hydrogen bonding sites into the frameworks. Such a control has been fine-tuned to induce high deliverable capacity in MOFs by changing gas pressure, temperature, and density. The establishment of a structure–property relationship for methane storage and successful pelletization of MOFs pave the way for MOF-based onboard natural gas storage. Deliverable ; Natural gas storage ; Metal-organic framework ; Methane ; Flexibility (engineering) ; Natural gas ; Materials science ; Hydrogen storage ; Nanotechnology ; Adsorption ; Environmental science ; Chemical engineering ; Waste management ; Chemistry ; Engineering ; Organic chemistry ; Composite material ; Systems engineering Metal-Organic Frameworks: Synthesis and Applications ; Nanoplatforms for cancer theranostics ; Catalytic Processes in Materials Science
Authors: Zahra Mahdieh
Source: The Mathematics Enthusiast (article, 2020-01-01)
Field: Materials Science — Biomaterials

ELECTROSPUN FIBERS WITH SMART DELIVERY OF THERAPEUTIC AGENTS Electrospinning is the most widely studied technique of producing fibers. Delivery of nanoparticles and therapeutic agents from electrospun fibers have potential uses in various fields including drug delivery, filtration, and cosmetics. However, controlling the delivery rate remains the main challenge. In the current study, core-shell structure fibers were developed with zinc oxide nanoparticles applied in the shell composition to improve the pore structure (release pathway) and mechanical stability. Fine-tuned delivery rates were achieved via loading different sizes of silver nanoparticles (Ag NP) inside the fiber core. In vitro drug release assays showed fast, slow, and intermediate delivery rates of 20 nm Ag NP, 110 nm Ag NP, and a mix of the two Ag NP, respectively. In the next step, temperature-controlled delivery rates were achieved via loading thermoresponsive microgel particles of poly(n-isopropylacrylamide) in addition to Ag NP inside the fiber core. In vitro drug release assays showed a fast release of Ag NP above the transition temperature and a slow release below the transition temperature. Ball-milling of the hydrogel was developed as a versatile, simple, and high yield technique of producing microgel particles (microgels). In vitro antibacterial tests confirmed the efficacy of the fiber meshes for anti-infection applications. Subcutaneous implantation of fiber meshes in a mouse model confirmed the in vivo drug release performance of the fibers. Fiber meshes were had appropriate biocompatibility and mechanical stability. The thorough characterization, in vitro and in vivo analyses of the fiber meshes confirmed their potential for prolonged drug delivery applications. Business ; Medicine ; Intensive care medicine ; Computer science Electrospun Nanofibers in Biomedical Applications ; Advanced Sensor and Energy Harvesting Materials ; Electrohydrodynamics and Fluid Dynamics
Authors: Maolin Bo | Liangjing Ge | Jibiao Li | Lei Li | Chuang Yao | Zhongkai Huang
Source: arXiv (Cornell University) (preprint, 2020-08-14)
Field: Materials Science — Materials Chemistry

Atomic bonding and binding energy of two-dimensional Bi/Li(110) heterojunctions via BOLS and BB model Combining the bond-order-length-strength (BOLS) and bonding and binding energy (BB) models with density functional theory (DFT) calculations, we studied the atomic bonding and binding energy behavior of Bi atoms adsorbed on the Li(110) surface. We found that the Bi atoms adsorbed on the Li(110) surface form two-dimensional (2D) geometric structures, including letter-, hexagon-, galaxy-, crown-, field-, and cobweb-shaped structures. Thus, we obtained the following quantitative information: (i) the field-shaped structure can be considered the bulk structure; (ii) the field-shaped structure of Bi atom formation has a 5d energy level of 22.727 eV, and in the letter shape structure, this energy is shifted to values greater than 0.342 eV;and (iii) the Bi/Li(110) heterojunction transfers charge from the inner Li atomic layer to the outermost Bi atomic layer. In addition, we analyzed the bonding and electronic dynamics involved in the formation of the Bi/Li(110) heterojunctions using zone-selective electron spectroscopy technology. This work provides a theoretical reference for the fine tuning of binding energies and chemical bonding at the interfaces of 2D metallic materials. Heterojunction ; Binding energy ; Atom (system on chip) ; Density functional theory ; Chemical bond ; Chemistry ; Electronic structure ; Atomic physics ; Materials science ; Crystallography ; Computational chemistry ; Physics ; Optoelectronics 2D Materials and Applications ; Graphene research and applications ; Advanced Thermoelectric Materials and Devices
Authors: Susan Daniel
Source:  (article, 2020-08-24)
Field: Materials Science — Polymers and Plastics

Biomembrane organic electronic devices Cell membranes localize and orchestrate the critical cellular processes, reactions, and sensing that give rise to life. The variety of lipids and proteins comprising these biomembranes enables fine-tuned control of the biological processes happening within them. However, to discover how such a complex system of myriad components gives rise to membrane properties and functions, we reduce the system to minimal components and in a step-wise and controlled manner, increase the complexity. The interface that delivers information about the processes under study is critical. We turn to organic electronics for its known compatibility with biological materials and their sensitive and convenient read out of information. I describe the advances in building the interface between cell membranes and organic electronics as well as the types of measurements and information that can be garnered from these devices. I highlight examples in ion channel biophysics, pathogen interactions, and biosensing. Electronics ; Nanotechnology ; Interface (matter) ; Computer science ; Membrane ; Biosensor ; Biochemical engineering ; Engineering ; Materials science ; Chemistry ; Electrical engineering Conducting polymers and applications ; Analytical Chemistry and Sensors ; Electrochemical sensors and biosensors
Authors: Annu Dahiya | Suraj Tamta | Manoj Verma
Source: Materials Today Proceedings (article, 2020-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Modulating plasmonic signatures of gold nanoparticles by fine tuning of surface roughness Materials science ; Surface plasmon resonance ; Surface roughness ; Plasmon ; Nanoparticle ; Raman scattering ; Colloidal gold ; Surface plasmon ; Nanotechnology ; Raman spectroscopy ; Surface finish ; Optoelectronics ; Optics ; Composite material Gold and Silver Nanoparticles Synthesis and Applications ; Plasmonic and Surface Plasmon Research ; Nonlinear Optical Materials Studies
Authors: Bingqing Lin | Xi Wu | Lin Xie | Yongqiang Kang | Hongda Du | Feiyu Kang | Jia Li | Lin Gan
Source: Angewandte Chemie (article, 2020-07-04)
Field: Materials Science — Materials Chemistry

Atomic Imaging of Subsurface Interstitial Hydrogen and Insights into Surface Reactivity of Palladium Hydrides Abstract Resolving interstitial hydrogen atoms at the surfaces and interfaces is crucial for understanding the mechanical and physicochemical properties of metal hydrides. Although palladium (Pd) hydrides hold important applications in hydrogen storage and electrocatalysis, the atomic position of interstitial hydrogen at Pd hydride near surfaces still remains undetermined. We report the first direct imaging of subsurface hydrogen atoms absorbed in Pd nanoparticles by using differentiated and integrated differential phase contrast within an aberration‐corrected scanning transmission electron microscope. In contrast to the well‐established octahedral interstitial sites for hydrogen in the bulk, subsurface hydrogen atoms are directly identified to occupy the tetrahedral interstices. DFT calculations show that the amount and the occupation type of subsurface hydrogen atoms play an indispensable role in fine‐tuning the electronic structure and associated chemical reactivity of the Pd surface. Hydrogen ; Interstitial defect ; Palladium ; Hydride ; Reactivity (psychology) ; Chemistry ; Hydrogen storage ; Metal ; Chemical physics ; Palladium hydride ; Scanning transmission electron microscopy ; Crystallography ; Materials science ; Inorganic chemistry ; Transmission electron microscopy ; Nanotechnology ; Catalysis ; Doping Hydrogen Storage and Materials ; Advanced Chemical Physics Studies ; Ammonia Synthesis and Nitrogen Reduction
Authors: Qingzheng Cheng | Chengfeng Zhou | Yuanfeng Pan | Brian K. Via
Source: Forest Products Journal (article, 2020-01-01)
Field: Materials Science — Biomaterials

Morphological Characterization of Wax and Surfactant–Encapsulated Microcrystalline Cellulose for Better Dispersion Abstract Encapsulation of cellulose with wax and surfactant is a physical way to restrict cellulose-to-cellulose attraction. Because wax is often used in the wood composite process, industrial manufacturers would not have to upgrade or add expensive equipment to handle cellulose addition. The encapsulated cellulose particles could easily be transported to composite and polymer facilities and blended in a homogeneous fashion for a multitude of products and composites. It was the objective of this study to utilize differential interference contrast (DIC) microscopy to characterize the wax and surfactant coverage and encapsulation morphology of the wax–surfactant–cellulose composite. The lengths and widths of the cellulose particles were significantly changed after encapsulation. DIC microscopy found that we could fine-tune wax coverage to control homogeneity and reduce fiber bundling during dispersion. It was found that surfactants were not necessary to enhance coverage if a 1:4 ratio of wax to microcrystalline cellulose was used. However, if more wax is desired, then surfactants may be necessary to suppress fiber bundles during dispersion. Wax ; Cellulose ; Pulmonary surfactant ; Microcrystalline cellulose ; Materials science ; Composite number ; Composite material ; Cellulose fiber ; Regenerated cellulose ; Chemical engineering ; Fiber Advanced Cellulose Research Studies ; Material Properties and Processing ; Lignin and Wood Chemistry
Authors: Jonathan A. Clinger | David Moreau | Robert Thorne
Source: Acta Crystallographica Section A Foundations and Advances (article, 2020-08-02)
Field: Materials Science — Materials Chemistry

Development of an alternative approach to time-resolved X-ray crystallography Development of X-ray free electron laser sources (XFELs) and methods for serial crystallography have driven major advances in time-resolved (TR) protein crystallography. TR-crystallography is a wonderful tool for understanding protein dynamics and catalysis, allowing much greater understanding of structural motions and intermediate states in proteins. Early TR work was largely limited to proteins whose conformational changes could be triggered optically using an intrinsic chromophore, and whose motions were reversible in the crystal, so that a single crystal could be pumped and reset multiple times to generate the diffraction data. Serial crystallography using microcrystals has enabled non-reversible motions to be observed by utilizing large amounts of sample and getting one diffraction image per crystal. These experiments wouldn't have been possible without the extraordinary brightness of XFELs and the newest generation of synchrotron sources. More recently, serial crystallography has incorporated chemical triggering via diffusion on millisecond timescales, short enough to reveal biologically important intermediate states. However, the barrier to entry for current optically or chemically triggered TR crystallography techniques at XFELs and synchrotrons is high. Very large numbers of similar size and morphology crystals must be generated. Optical excitation and/or crystal mixing and delivery systems are complex and must be integrated into the beamline. Fine tuning for a given protein crystal system and efficient serial data collection using these methods requires multiple collaborators, knowledgeable beamline staff, and often large amounts of instrument time at the very few available beamlines suited to these experiments. This complexity puts TR crystallography beyond the reach of most investigators in the wider structural biology community. Alternative methods are needed to allow TR crystallography to be exploited fully by the field. Ideally, these methods should require far fewer crystals, allow data collection from standard MX beamlines without need for special sample delivery apparatus, and allow multiple routes to reaction initiation. We have been developing an alternative method to time-resolved serial crystallography that decouples the sample preparation and reaction evolution times from the data collection time, allows both optical and chemical triggering, and requires only remote data collection at standard synchrotron beamlines. Here we present preliminary data for our new TR-crystallography technique. Crystallography ; X-ray crystallography ; X-ray ; Materials science ; Chemistry ; Physics ; Diffraction ; Optics X-ray Diffraction in Crystallography ; Enzyme Structure and Function ; Advanced X-ray Imaging Techniques
Authors: Kailyn Cohen
Source: Digital Commons - Ursinus (Ursinus College) (article, 2020-05-03)
Field: Chemistry — Inorganic Chemistry

Redox Properties of the de Novo Designed Due Ferri Single-Chain (G4DFsc) Model Protein The due ferri single chain (DFsc) protein is a de novo designed four-helix bundle designed to mimic the 2-histidine/4-carboxylate active site of natural non-heme diiron enzymes such as methane monooxygenase and ribonucleotide reductase. Previously, a library of eight G4DFsc variants was developed with between two and six His residues at the active site using site-directed mutagenesis to systematically replace each Glu residue. In order to better understand the structure–function relationships of these variants, the reduction–oxidation properties of these diiron proteins were probed using cyclic voltammetry. Understanding how Nature fine-tunes catalytic activity in these proteins can influence the design of artificial proteins for modern applications such as biofuel cells, biosensors, and catalysts. Current work focuses on the cyclic voltammetry of G4DFsc-Fe2 with changes in both pH and anaerobic conditions. Upon addition of the diiron protein or under anaerobic conditions, oxygen-sensitive cyclic voltammetric peaks decrease in current, leading to the conclusion that G4DFsc-Fe2 behaves as an oxygen scavenger, mimicking the behavior of natural non-heme diiron proteins like rubrerythrin. Redox ; Chain (unit) ; Chemistry ; Computer science ; Physics ; Inorganic chemistry Metal-Catalyzed Oxygenation Mechanisms ; Protein Structure and Dynamics ; Electron Spin Resonance Studies