jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Mirco Eckardt | Sabrina L. J. Thomä | Martin Dulle | Gerald Hörner | Birgit Weber | Stephan Förster | Mirijam Zobel
Source: ChemistryOpen (article, 2020-11-01)
Field: Materials Science — Materials Chemistry

Long‐Term Colloidally Stable Aqueous Dispersions of ≤5 nm Spinel Ferrite Nanoparticles Applications in biomedicine and ferrofluids, for instance, require long-term colloidally stable, concentrated aqueous dispersions of magnetic, biocompatible nanoparticles. Iron oxide and related spinel ferrite nanoparticles stabilized with organic molecules allow fine-tuning of magnetic properties via cation substitution and water-dispersibility. Here, we synthesize≤5 nm iron oxide and spinel ferrite nanoparticles, capped with citrate, betaine and phosphocholine, in a one-pot strategy. We present a robust approach combining elemental (CHN) and thermal gravimetric analysis (TGA) to quantify the ratio of residual solvent molecules and organic stabilizers on the particle surface, being of particular accuracy for ligands with heteroatoms compared to the solvent. SAXS experiments demonstrate the long-term colloidal stability of our aqueous iron oxide and spinel ferrite nanoparticle dispersions for at least 3 months. By the use of SAXS we approved directly the colloidal stability of the nanoparticle dispersions for high concentrations up to 100 g L<sup>-1</sup>. Spinel ; Nanoparticle ; Materials science ; Aqueous solution ; Term (time) ; Ferrite (magnet) ; Chemical engineering ; Colloid ; Nanotechnology ; Chemistry ; Metallurgy ; Composite material ; Physics ; Physical chemistry ; Engineering Magnetic Properties and Synthesis of Ferrites ; Iron oxide chemistry and applications ; Nanoparticle-Based Drug Delivery
Authors: Yunyan Qiu | Hongliang Chen | Yuanning Feng | Margaret E. Schott | J. Fraser Stoddart
Source: Chem (article, 2020-04-01)
Field: Materials Science — Materials Chemistry

Stitching up the Belt[n]arenes Image stitching ; Geology ; Computer science ; Artificial intelligence Carbon Nanotubes in Composites ; Synthesis and Properties of Aromatic Compounds ; Graphene research and applications
Authors: Ravi Karki | Dipak Adhikari | Kapil Adhikari | Nurapati Pantha
Source: Himalayan Physics (article, 2020-12-31)
Field: Chemistry — Inorganic Chemistry

Metal Organic Frameworks (MOFs) as efficient carrier for targeted nanodrug delivery A controllable and targeted drug delivery system development is imperative and important to reduce side effects and enhance the therapeutic efficacy of drugs. Metal-organic frameworks (MOFs), an emerging type of hybrid porous materials synthesized from metal ions or clusters abridged by organic linkers. They have attracted increasing attention in the recent years owing to the unique physical structures possessed, and the potential for wide range of applications. The superior properties of MOFs, such as well-deﬁned pore aperture, tailorable composition and structure, tunable size, versatile functionality, high agent loading, and improved biocompatibility, have made them promising candidates as drug delivery hosts. MOFs for drug encapsulation and delivery is of great interest and many very promising results have been found, indicating that these porous solids exhibit several advantages over existing systems. This review highlights the recent advances in the synthesis, functionalization, and applications of MOFs in nanodrug delivery, and has classiﬁed them using drug loading strategies. Metal-organic framework ; Nanotechnology ; Drug delivery ; Materials science ; Biocompatibility ; Targeted drug delivery ; Surface modification ; Porosity ; Chemical engineering ; Chemistry ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Dendrimers and Hyperbranched Polymers ; Boron and Carbon Nanomaterials Research
Authors: Umut Uğur Özköse | Sevgi Gülyüz | Umut Can Öz | Mehmet Atilla Taşdelen | Onur Alptürk | Asuman Bozkır | Özgür Yılmaz
Source: eXPRESS Polymer Letters (article, 2020-01-01)
Field: Chemistry — Organic Chemistry

Development of self-assembled poly(2-ethyl-2-oxazoline)-b-poly(ε-caprolactone) (PEtOx-b-PCL) copolymeric nanostructures in aqueous solution and evaluation of their morphological transitions Amphiphilic block copolymers are known to self-assemble into various morphologies, including ellipsoids, tubular structures, toroids, vesicles, micellar structures. In this paper, we discuss the synthesis of copolymeric nanostructures (CNs) using poly(2-ethyl-2-oxazoline)-block-poly(-caprolactone) (PEtOx-b-PCL) amphiphilic block copolymers. Our data indicate that -varying the molecular weight and the number of repeating units dictate the nature of morphology. That is, the formation of self-assembled morphologies from ellipsoid to rod-like architectures are observed in aqueous solution, depending on the mass ratio of the hydrophilic block (f PEtOx ). To best of our knowledge, this is the first report on the morphological transitions of PEtOx-b-PCL amphiphilic block copolymer-based CNs with different f PEtOx values in the literature. Materials science ; Caprolactone ; Oxazoline ; Aqueous solution ; Chemical engineering ; Polymer chemistry ; Polymer science ; Copolymer ; Organic chemistry ; Polymer ; Composite material ; Chemistry ; Catalysis Advanced Polymer Synthesis and Characterization ; biodegradable polymer synthesis and properties
Authors: Maren Wissing | Maximilian Niehues | Bart Jan Ravoo | Armido Studer
Source: Advanced Synthesis & Catalysis (article, 2020-04-08)
Field: Materials Science — Materials Chemistry

Synthesis and Immobilization of Metal Nanoparticles Using Photoactive Polymer‐Decorated Zeolite L Crystals and Their Application in Catalysis Abstract A facile route to generate Au and Pd nanoparticles (NPs) on zeolite L crystals decorated with photoactive polymer brushes is described. The polymers used in this approach serve a dual role: Upon irradiation with UV light, they release highly reducing ketyl radicals in a Norrish‐Type‐I reaction. These radicals serve as one electron donors to reduce metal salts to the corresponding metal NPs. At the same time the polymer shell stabilizes the in situ generated metal NPs. It is shown that the zeolite‐polymer‐NP composites can be used as recyclable catalysts for the oxidation of benzylic alcohols to aldehydes and the stereoselective semihydrogenation of alkynes to Z ‐alkenes. The polymer shell in these hybrid catalysts protects the NPs from aggregation and also alters their catalytic properties. magnified image Chemistry ; Zeolite ; Catalysis ; Polymer ; Nanoparticle ; Metal ; Ketyl ; Radical ; Photochemistry ; Polymer chemistry ; Chemical engineering ; Organic chemistry ; Nanotechnology ; Materials science Catalytic Processes in Materials Science ; Nanocluster Synthesis and Applications ; Nanomaterials for catalytic reactions
Authors: Sarah Kim | Sein Min | Heelim Chae | Hye Jin Jeong | Sung Keon Namgoong | Sangwon Oh | Keunhong Jeong
Source: Molecules (article, 2020-07-23)
Field: Chemistry — Spectroscopy

Hyperpolarization of Nitrile Compounds Using Signal Amplification by Reversible Exchange Signal Amplification by Reversible Exchange (SABRE), a hyperpolarization technique, has been harnessed as a powerful tool to achieve useful hyperpolarized materials by polarization transfer from parahydrogen. In this study, we systemically applied SABRE to a series of nitrile compounds, which have been rarely investigated. By performing SABRE in various magnetic fields and concentrations on nitrile compounds, we unveiled its hyperpolarization properties to maximize the spin polarization and its transfer to the next spins. Through this sequential study, we obtained a ~130-fold enhancement for several nitrile compounds, which is the highest number ever reported for the nitrile compounds. Our study revealed that the spin polarization on hydrogens decreases with longer distances from the nitrile group, and its maximum polarization is found to be approximately 70 G with 5 μL of substrates in all structures. Interestingly, more branched structures in the ligand showed less effective polarization transfer mechanisms than the structural isomers of butyronitrile and isobutyronitrile. These first systematic SABRE studies on a series of nitrile compounds will provide new opportunities for further research on the hyperpolarization of various useful nitrile materials. Nitrile ; Hyperpolarization (physics) ; Polarization (electrochemistry) ; Chemistry ; Spin isomers of hydrogen ; Spins ; Induced polarization ; Photochemistry ; Stereochemistry ; Nuclear magnetic resonance spectroscopy ; Organic chemistry ; Physics ; Physical chemistry ; Condensed matter physics ; Hydrogen Advanced NMR Techniques and Applications ; Solid-state spectroscopy and crystallography ; Electron Spin Resonance Studies
Authors: Yi Chen | Huang Liu | Haojing Yin | Qi Zhu | Gang Yao | Ning Gu
Source: Frontiers in Chemistry (article, 2020-04-28)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Hierarchical Fabrication of Plasmonic Superlattice Membrane by Aspect-Ratio Controllable Nanobricks for Label-Free Protein Detection Plasmonic superlattice membrane exhibits remarkable functional properties that are emerging from engineered assemblies of well-defined "meta-atoms," which is featured as a conceptual new category of two-dimensional optical metamaterials. The ability to build plasmonic membranes over macroscopic surfaces but with nanoscale ordering is crucial for systematically controlling the light-matter interactions and represents considerable advances for the bottom-up fabrication of soft optoelectronic devices and circuits. Through rational design, novel nanocrystals, and by engineering the packing orders, the hybridized plasmon signature can be customized, promoting controllable near-field confinement for surface-enhanced Raman scattering (SERS) based detection. However, building such 2D architectures has proven to be remarkably challenging due to the complicated interparticle forces and multiscale interactions during self-assembly. Here, we report on the fabrication of ultralong-nanobrick-based giant plasmonic superlattice membranes as high-performance SERS substrates for ultrasensitive and label-free protein detection. Using aspect-ratio controllable short-to-ultralong nanobricks as building blocks, we construct three distinctive plasmonic membranes by polymer-ligand-based strategy in drying-mediated self-assembly at the air/water interfaces. The plasmonic membranes exhibit monolayered morphology with nanoscale assembled ordering but macroscopic lateral dimensions, inducing enhanced near-field confinement and uniform hot-spot distribution. By choosing 4-aminothiophenol and bovine serum albumin (BSA) as a model analyte, we establish an ultrasensitive assay for label-free SERS detection. The detection limit of BSA can reach 15 nM, and the enhancement factor reached 4.3 × 10<sup>5</sup>, enabling a promising avenue for its clinical application in ultrasensitive biodiagnostics. Fabrication ; Superlattice ; Plasmon ; Nanotechnology ; Membrane ; Materials science ; Optoelectronics ; Chemistry ; Medicine ; Biochemistry Gold and Silver Nanoparticles Synthesis and Applications ; Advanced biosensing and bioanalysis techniques ; Plasmonic and Surface Plasmon Research
Authors: Solomon Omwoma
Source: Journal of Analytical Methods in Chemistry (article, 2020-03-30)
Field: Materials Science — Materials Chemistry

Trace Metal Detection in Aqueous Reservoirs Using Stilbene Intercalated Layered Rare-Earth Hydroxide Tablets Contamination of aquatic reservoirs with metal ions is a slow gradual process that is not easy to detect. Consequences of the metal ions, especially the ones with high atomic numbers (heavy metals) at high concentrations, are severe and irreversible in aquatic reservoirs. As such, early detection mechanisms, especially at trace concentration, are essential for mitigation measures. In this work, a new, robust, and effective tool for trace metal detection and monitoring in aqueous solutions has been developed. Tablets (1 mm thick and similar to medicinal tablets) were manufactured from a powder comprising stilbene intercalated into gallery spaces of lanthanide-containing layered double hydroxides. The tablets were placed in a water column having different concentrations of Pb<sup>2+</sup> and Cu<sup>2+</sup> ions, and the water was allowed to flow for 45 minutes at a flow rate of 100 ml/s. Thereafter, the tablets were dried and made to powder, and their phosphorescence was measured. The gradual stilbene phosphorescence turnoff in the tablets from various concentrations of metal ions was correlated with sorption amounts. The tablets were able to detect effectively metal ions (up to Pb<sup>2+</sup> 1.0 mmol/L and Cu<sup>2+</sup> 5.0 mmol/L) in the aqueous media. As such, the concentrations of Pb<sup>2+</sup> and Cu<sup>2+</sup> ions at trace levels were determined in the test solutions. This method provides a real-time metal ion analysis and does not involve sampling of water samples for analysis in the laboratory. TRACE (psycholinguistics) ; Aqueous solution ; Hydroxide ; Rare earth ; Metal ; Trace metal ; Metal hydroxide ; Earth (classical element) ; Chemistry ; Materials science ; Mineralogy ; Geology ; Inorganic chemistry ; Environmental chemistry ; Metallurgy ; Physics ; Organic chemistry Lanthanide and Transition Metal Complexes ; Radioactive element chemistry and processing ; Metal-Organic Frameworks: Synthesis and Applications
Authors: Elizabeth M. Timmers | José Rodrigo Magaña | Sandra M. C. Schoenmakers | Peter Fransen | Henk M. Janssen | Ilja K. Voets
Source: International Journal of Molecular Sciences (article, 2020-12-30)
Field: Chemistry — Organic Chemistry

Sequence of Polyurethane Ionomers Determinative for Core Structure of Surfactant–Copolymer Complexes The core of micelles self-assembled from amphiphiles is hydrophobic and contains little water, whereas complex coacervate core micelles co-assembled from oppositely charged hydrophilic polymers have a hydrophilic core with a high water content. Co-assembly of ionic surfactants with ionic-neutral copolymers yields surfactant-copolymer complexes known to be capable of solubilizing both hydrophilic and hydrophobic cargo within the mixed core composed of a coacervate phase with polyelectrolyte-decorated surfactant micelles. Here we formed such complexes from asymmetric (<b>PUI-A2</b>) and symmetric (<b>PUI-S2</b>), sequence-controlled polyurethane ionomers and poly(<i>N</i>-methyl-2-vinylpyridinium iodide)<sub>29</sub>-<i>b</i>-poly(ethylene oxide)<sub>204</sub> copolymers. The complexes with <b>PUI-S2</b> were 1.3-fold larger in mass and 1.8-fold larger in radius of gyration than the <b>PUI-A2</b> complexes. Small-angle X-ray scattering revealed differences in the packing of the similarly sized PUI micelles within the core of the complexes. The <b>PUI-A2</b> micelles were arranged in a more ordered fashion and were spaced further apart from each other (10 nm vs. 6 nm) than the <b>PUI-S2</b> micelles. Hence, this work shows that the monomer sequence of amphiphiles can be varied to alter the internal structure of surfactant-copolymer complexes. Since the structure of the micellar core may affect both the cargo loading and release, our findings suggest that these properties may be tuned through control of the monomer sequence of the micellar constituents. Micelle ; Coacervate ; Copolymer ; Pulmonary surfactant ; Polymer chemistry ; Chemistry ; Amphiphile ; Polyelectrolyte ; Polymer ; Chemical engineering ; Ethylene oxide ; Monomer ; Radius of gyration ; Ionic bonding ; Hydrodynamic radius ; Materials science ; Organic chemistry ; Chromatography ; Aqueous solution Surfactants and Colloidal Systems ; Advanced Polymer Synthesis and Characterization ; Polymer Surface Interaction Studies
Authors: Ahsen Ezel Bildik Dal | Martin A. Hubbe
Source: BioResources (review, 2020-11-01)
Field: Materials Science — Biomaterials

Hydrophobic copolymers added with starch at the size press of a paper machine: A review of findings and likely mechanisms This article reviews publications with the goal of understanding the role of hydrophobic copolymers added to size-press starch as a means to make paper products more resistant to penetration by aqueous fluids. The underlying technology is considered, including background related to starch, size-press equipment, and various hydrophobic copolymers and latex products that have been evaluated. The resulting hydrophobization of the paper has been reported to depend not only on the dosage of the hydrophobic additive, but also on its molecular mass and ionic form. The mechanism appears to rely on an ability of starch to serve as a temporary host for hydrophobic compounds in aqueous solution. It has been proposed that hydrophobic copolymers added with size press starch tend to migrate to the air interface during drying of the starch film, thus allowing the low-energy functional groups, such as styrene or alkyl chains, to face outwards. Further research is needed to address various mechanistic questions. There may be opportunities to further raise the performance of this type of technology as practiced within paper production factories. Copolymer ; Starch ; Aqueous solution ; Materials science ; Chemical engineering ; Hydrophobic effect ; Alkyl ; Penetration (warfare) ; Polymer chemistry ; Polymer science ; Chemistry ; Organic chemistry ; Polymer ; Mathematics Advanced Cellulose Research Studies ; Material Properties and Processing ; Nanocomposite Films for Food Packaging
Authors: Rini Umiyati | Ria Millati | Teguh Ariyanto | Chusnul Hidayat
Source: Biodiversitas Journal of Biological Diversity (article, 2020-06-28)
Field: Materials Science — Biomaterials

Calophyllum inophyllum extract as a natural enhancer for improving physical properties of bioplastics and natural antimicrobial Abstract. Umiyati R, Millati R, Ariyanto T, Hidayah C. 2020. Calophyllum inophyllum extracts as a natural enhancer for improving physical properties of bioplastics and antimicrobial activity. Biodiversitas 21: 3294-3302. The utilization of Calophyllum inophyllum (or nyamplung) cake (NC) is still limited, only as fertilizer and animal feed. This research aimed to evaluate C. inophyllum (or nyamplung) cake extract (NCE) and its utilization as an antimicrobial agent in packaging material. Bioplastics were prepared by the thermo-compression method. The results showed that the NC and NCE contained tannins and amide groups. They had antimicrobial activities toward Escherichia coli and Staphylococcus aureus. Only NCE had antifungal toward Aspergillus nigger. Therefore, HPS bioplastic containing NCE exhibited antibacterial. Besides, NCE and NC contained carbonyl and amide groups. As a result, NCE addition was able to significantly increase tensile strength (σ) of bioplastic, in which it was about 1.5 times higher compared to control. But NCE did not have a significant effect on elongation at break (ε) and modulus of elasticity (Y). Water solubility (WS) and water vapor permeability (WVP) were reduced with an increase in NCE concentration. HPS-NCE bioplastics show a finer and more homogeneous texture compared to control bioplastic. The NCE shows the ability as a natural enhancer for improving bioplastics properties as well as function as an antibacterial agent against Escherichia coli and Staphylococcus aureus bacteria in bioplastics. Bioplastic ; Antimicrobial ; Food science ; Chemistry ; Materials science ; Microbiology ; Biology ; Organic chemistry Nanocomposite Films for Food Packaging ; Waste Management and Recycling
Authors: Marek Trzciński | Grażyna Balcerowska‐Czerniak | A. Bukaluk
Source: Catalysts (article, 2020-06-02)
Field: Materials Science — Surfaces, Coatings and Films

XPS Studies of the Initial Oxidation of Polycrystalline Rh Surface Increased interest in the oxidation process of polycrystalline rhodium, observed in recent years, is the result of its application in exhaust catalytic converters. However, most studies have involved sample surfaces with low Miller indices. In our research, we investigated polycrystalline rhodium foil containing crystallographically different, highly stepped, µm-sized crystallites. These crystallites were exposed to identical oxidizing conditions. To determine crystallographic orientation, the electron backscattering diffraction (EBSD) method was used. To investigate the initial stages of oxidation on the individual crystallites of Rh, X-ray photoelectron spectroscopy (XPS) studies were performed. The results obtained for the individual crystallites were compared and analyzed using chemical state quantification of XPS data and multivariate statistical analysis (MVA). Crystallite ; X-ray photoelectron spectroscopy ; Rhodium ; Materials science ; Oxidizing agent ; Diffraction ; Analytical Chemistry (journal) ; Catalysis ; Chemistry ; Chemical engineering ; Metallurgy ; Optics ; Organic chemistry Electron and X-Ray Spectroscopy Techniques ; Advanced Materials Characterization Techniques ; Catalytic Processes in Materials Science
Authors: Greg Jenson | Gurjap Singh | Jay K. Bhama | Albert Ratner
Source: Energies (article, 2020-01-28)
Field: Materials Science — Polymers and Plastics

Hydrogel Leclanché Cell: Construction and Characterization A liquid-to-gel based Leclanché cell has been designed, constructed and characterized for use in implantable medical devices and other applications where battery access is limited. This well-established chemistry will provide reliable electrochemical potential over a wide range of applications and the novel construction provides a solution for the re-charging of electrodes in hard to access areas such as an internal pacemaker. The traditional Leclanché cell, comprised of zinc (anode) and manganese dioxide (cathode), conductive carbon powder (acetylene black or graphite), and aqueous electrolyte (NH4Cl and ZnCl2), has been suspended in an agar hydrogel to simplify construction while maintaining electrochemical performance. Agar hydrogel, saturated with electrolyte, serves as the cell support and separator allowing for the discharged battery suspension to be easily replaced once exhausted. Different amounts of active anode/cathode material have been tested and discharge characteristics have been plotted. It has been found that for the same amount of active material, acetylene black batteries have higher energy density compared to graphite batteries. Graphite batteries also discharge faster compared to acetylene black batteries. The results support further development of liquid batteries that can be replaced and refilled upon depletion. Separator (oil production) ; Anode ; Electrolyte ; Carbon black ; Cathode ; Materials science ; Battery (electricity) ; Electrochemistry ; Graphite ; Electrode ; Chemical engineering ; Electrochemical cell ; Nanotechnology ; Chemistry ; Composite material Conducting polymers and applications ; Electrochemical sensors and biosensors ; Advanced Sensor and Energy Harvesting Materials