jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Meredith J. Hampton
Source: Carolina Digital Repository (University of North Carolina at Chapel Hill) (article, 2019-08-13)
Field: Materials Science — Surfaces, Coatings and Films

Nano-patterning of inorganic materials for photovoltaic applications In this work, the pattern replication in non-wetting templates (PRINT) technique has been utilized for the patterning of inorganic materials including metal oxides and quantum dots for hybrid inorganic-organic solar cells. The PRINT technique is an attractive method for solar cell production because of its compatibility with a wide range of organic and inorganic reagents relevant to BHJ fabrication, amenability for scale-up, and application to large area device fabrication. The PRINT process was used to pattern inorganic oxides, including titania, on a sub-500 nm length scale. The inherent flexibility of this methodology was demonstrated by generating patterns on a variety of substrates, with aspect ratios greater than 1, with a second layer of features on top of an initial layer without pattern destruction, and with sub-100 nm sized features for photovoltaics applications. This technique was applied to hybrid solar cell technology by fabricating solar cells with these sub-100 nm titania features. The patterned titania/polymer devices showed a two-fold improvement in power conversion efficiency (PCE) when compared to flat titania/polymer devices. Furthermore, CdSe quantum dots (QDs) were synthesized and then used for patterning. The inert nature of the PFPE molds was demonstrated through the patterning of QDs with different surface ligands in a variety of solvents. Nanometer-scale diffraction gratings have been successfully replicated with CdSe QDs and subsequently coated with a conjugated polymer film for PV device fabrication. Finally, the PRINT technique has also been extended to fabrication schemes for different optical applications. An ordered template for surface-enhanced Raman spectroscopy (SERS) was fabricated with 120 nm wide holes that allowed for the formation of Ag nanoparticle dimers using a meniscus force deposition method. These dimers provided hotspots where an enhanced Raman signal was observed. Additionally, in effort to fabricate a superlens capable of directly imaging subwavelength structures, a simple metamaterial diffraction grating device was generated by replicating a blazed diffraction grating in PMMA on top of alternating metal dielectric layers. In this device, the amplification and conversion of evanescent waves into propagating ones was demonstrated. Photovoltaic system ; Nanotechnology ; Nano- ; Materials science ; Engineering ; Electrical engineering ; Composite material Optical Coatings and Gratings ; Electrophoretic Deposition in Materials Science ; Nanotechnology research and applications
Authors: David Kiefer
Source: Chalmers Research (Chalmers University of Technology) (article, 2019-01-01)
Field: Materials Science — Polymers and Plastics

Molecular Doping of Polar Conjugated Polymers Organic semiconductors may enable a wide range of flexible electronics, such as flexible displays or solar cells. Conjugated polymers constitute one of the most widely studied class of organic semiconductors. Molecular doping is an important tool to adjust their electrical conductivity through introduction of negative or positive charges by addition of molecular dopants. However, solution-processing of conjugated polymers with molecular dopants is limited due to precipitation and a low number of charges formed per dopant molecule as a result of dopant aggregation or inappropriate energy levels. Thus, large amounts of dopant are required that compromise the nanostructure of conjugated polymers and in turn reduce the electrical conductivity, which is furthermore sensitive to elevated temperatures or the exposure to air in case of n-doping. Therefore, ways that mitigate processing issues and increase the efficiency and stability of molecular doping are highly desired.This thesis explores several concepts that may allow to improve the efficiency of molecular doping. A reduction of the required amount of dopant molecules is achieved by enhancing the compatibility of conjugated polymer:dopant pairs, which results in increased numbers of charges that are created per dopant molecule. In particular, polar side chains on conjugated polymers permit processing of polymer:dopant pairs from the same solution and largely suppress dopant aggregation resulting in improved electrical conductivity for p- and n-doping. Additionally, both the thermal stability of p-doped and air stability of n-doped films are found to benefit from polar side chains. Further, a low ionisation energy of conjugated polymers gives rise to dianion formation of common p-dopants. This double doping results in formation of two charges per dopant molecule and, thus, allows doubling of the doping efficiency. The concepts presented in this thesis provide several important design rules to guide the development of more efficient and stable molecularly doped conjugated polymers. Dopant ; Doping ; Conjugated system ; Polymer ; Materials science ; Nanotechnology ; Organic electronics ; Organic semiconductor ; Chemical physics ; Organic chemistry ; Optoelectronics ; Chemistry ; Transistor ; Electrical engineering ; Composite material Conducting polymers and applications ; Organic Electronics and Photovoltaics ; Analytical Chemistry and Sensors
Authors: L. Yu. Klimenko | Г. Л. Шкарлат | З. В. Шовкова | O. V. Kolisnyk
Source: Journal of organic and pharmaceutical chemistry (article, 2019-06-14)
Field: Chemistry — Analytical Chemistry

Development and validation of HPLC/UV-procedures for quantification of metronidazole in the blood and urine Metronidazole belongs to the group of antiprotozoal medicines and widely used for the treatment of infectious diseases; the medicine has a number of side effects manifested by usual symptoms of acute intoxication, especially when interacting with other drugs and alcohol.Aim. To apply the system of MiLiChrome® A-02 HPLC-analyzer widely used in the Ukrainian laboratories of forensic toxicology for the metronidazole quantitative determination in biological fluids and carry out validation of the procedures developed.Materials and methods. The sample preparation of blood and urine was carried out by extraction with acetonitrile and 2-propanol followed by separation of the organic layer under the conditions of the aqueous phase saturation with ammonium sulfate. Previously blood and urine were treated with acids. Isolation was carried out in the strong acid, neutral and weak alkaline medium.Results and discussion. To find the optimal conditions of the sample preparation such validation parameters as specificity/selectivity and recovery were determined. The results of the blank samples analysis were acceptable for all variants of the sample preparation procedures. Recovery values were reproducible for all procedures of analysis studied, but efficacy of metronidazole isolation was variable – from 85% to 97 %. The results of verification of metronidazole stability showed the necessity to carry out all measurements within 12 hours after obtaining the solutions to be analyzed. The results of determination of linearity, accuracy and precision were the evidenceof acceptable systematic and random errors of the HPLC/UV-procedures studied in the variant of the method of calibration curve, method of standard and method of additions.Conclusions. The set of HPLC/UV-procedures for the metronidazole quantitative determination in blood and urine has been developed. Validation of the procedures developed has been carried out. Chromatography ; Metronidazole ; High-performance liquid chromatography ; Sample preparation ; Urine ; Chemistry ; Antibiotics Analytical chemistry methods development ; Antibiotics Pharmacokinetics and Efficacy ; Infectious Encephalopathies and Encephalitis
Authors: Abhik Chatterjee
Source: Science & Technology Journal (article, 2019-07-01)
Field: Chemistry — Analytical Chemistry

Electrodes for Estimation of Nimesulide Drug using Voltammetry Technique: A Revisit Nimesulide is a pain-killer and falls in the category of non-steroidal anti-inflammatory drug. It can reduce different types of pain. Nimesulide is a safe drug but uncontrolled use of this medicine creates many problems. So detection and estimation of nimesulide is very important. Electro analytical methods are good choice for detection and estimation. Among them, voltammetry is one of the good method in this twenty-first century. In this review, different electrode materials for voltammetric study have been presented with detection limit. Nimesulide ; Voltammetry ; Detection limit ; Drug ; Electrode ; Computer science ; Medicine ; Chemistry ; Pharmacology ; Chromatography ; Electrochemistry Analytical Methods in Pharmaceuticals ; Analytical Chemistry and Chromatography ; Electrochemical sensors and biosensors
Authors: Surabhi Gupta | Tomoharu Kataoka | Masao Watanabe | Mamoru Ishikiriyama | Noriyoshi Matsumi
Source: Journal of Applied Polymer Science (article, 2019-06-24)
Field: Chemistry — Organic Chemistry

Fine‐tuning of phase behavior of oxazoline copolymer‐based organic–inorganic hybrids as solid‐supported sol–gel materials ABSTRACT Silica‐supported organic–inorganic polymer hybrids were synthesized via in situ sol–gel condensation of silica monomer in the presence of oxazoline copolymer. A stable copolymer of 2‐ethyl‐2‐oxaoline and 2‐isopropyl‐2‐oxazoline was prepared using methyl p‐tosylate as the living polymerization initiator with molecular mass of 4200 g mol −1 . Lower critical solution temperature (LCST) of this copolymer was thermally found to be at 77 °C. The copolymer was mixed with tetramethoxysilane (TMOS) in different amounts (0.039:1 to 0.158:1 weight ratios) via in situ sol–gel condensation to produce organic–inorganic hybrids including thermosensitive copolymer. Tuning of these solid‐supported materials showed sharp phase transitions changes in a temperature range from 42 to 58 °C, which was confirmed using differential scanning calorimetry. Enthalpy of the phase transition was also calculated using the area above the endothermic peak. A typical concave curve was obtained for LCST‐type phase diagram suggesting the dependence of phase transition temperature on the concentration of the copolymer in the hybrid. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 48163. Lower critical solution temperature ; Copolymer ; Materials science ; Polymer chemistry ; Differential scanning calorimetry ; Polymer ; Endothermic process ; Chemical engineering ; Enthalpy ; Monomer ; Phase (matter) ; Chemistry ; Physical chemistry ; Organic chemistry ; Thermodynamics ; Composite material ; Adsorption Advanced Polymer Synthesis and Characterization ; Polyoxometalates: Synthesis and Applications ; Silicone and Siloxane Chemistry
Authors: Andrea Cingolani | Rita Mazzoni | Valerio Zanotti | Matteo Sanviti | Laura Mazzocchetti | Tiziana Benelli | Loris Giorgini
Source: AIP conference proceedings (article, 2019-01-01)
Field: Materials Science — Polymers and Plastics

Bis-amino functionalized iron N-heterocyclic carbene as epoxy resins hardener and flame behaviour modifier The synthesis of a bis-amino-functionalized iron cyclopentadienone N-heterocyclic carbene complex (1) has been fine tuned to develop an hardener for the production of a novel hybrid epoxy resin (EP) with the aim of also reducing fire hazard. The synthesized organometallic complex well performs as curing agent both with DGEBA, preliminary employed, and the commercial pre-polymer Elan-tron® EC 157 in different formulations (loading range 5, 7.5, 10%wt). Thermogravimetric analyses revealed that curing temperature shows a significant intumescent char residual (yield 25%), possibly to due iron presence. DSC indicated that reaction rate and glass transition increase with complex 1 content, and under isothermal conditions the best performances have been identified at 170 °C and 7.5%wt of 1. The latter conditions has been finally employed for tests in cone calorimeter displaying a charring action of the complex included in the resins, together with an early ignition that has to be addressed playing on the formulation and chemical structure of the hardener. Epoxy ; Char ; Charring ; Thermogravimetric analysis ; Cone calorimeter ; Curing (chemistry) ; Materials science ; Carbene ; Isothermal process ; Polymer chemistry ; Polymer ; Thermosetting polymer ; Glass transition ; Yield (engineering) ; Chemical engineering ; Chemistry ; Composite material ; Pyrolysis ; Organic chemistry ; Catalysis Flame retardant materials and properties ; N-Heterocyclic Carbenes in Organic and Inorganic Chemistry ; Synthesis and properties of polymers
Authors: V. Ganesan | V. Vijayakumar
Source: Superlattices and Microstructures (article, 2019-05-08)
Field: Materials Science — Materials Chemistry

Monolayer SiP nanosheets for near and mid-infrared optoelectronic device applications - A DFT approach Materials science ; Band gap ; Optoelectronics ; Monolayer ; Direct and indirect band gaps ; Phonon ; Semiconductor ; Doping ; Infrared ; Electronic structure ; Nanotechnology ; Condensed matter physics ; Optics ; Physics 2D Materials and Applications ; Nanowire Synthesis and Applications ; Graphene research and applications
Authors: Ning Xu | Toshikazu Ono | Yoshio Hisaeda
Source: Chemistry - A European Journal (article, 2019-07-15)
Field: Materials Science — Materials Chemistry

Cover Feature: Symmetry Reduction of Porphycenes with Finely Tuned Optical and Electronic Properties through Oxidative Cyclization of <i>E</i>/<i>Z</i>‐Mixed Dipyrroethenes (Chem. Eur. J. 50/2019) The main obstacle to a widespread application of porphycenes, the first structural isomer of porphyrins, lies in the lack of an efficient and economical method of their production. This study reports a series of unsymmetrical porphycenes prepared by acid-catalyzed oxidative coupling of AA- and BB-dipyrroethenes, or AB-type dipyrroethenes. The type and position of substituents in the unsymmetric porphycenes enabled fine-tuning of the optical and electronic properties. The graphic shows an example of crystal structure of AABB-porphycene that contains 3,5-bis(trifluoromethyl)benzene at 9,10-position and benzene at 19,20-position of the porphycene framework. More information can be found in the Full Paper by N. Xu, T. Ono, and Y. Hisaeda on page 11680. Benzene ; Chemistry ; Structural isomer ; Position (finance) ; Feature (linguistics) ; Stereochemistry ; Crystallography ; Computational chemistry ; Organic chemistry Porphyrin and Phthalocyanine Chemistry ; Molecular Sensors and Ion Detection ; Surface Chemistry and Catalysis
Authors: Alberto Ambrosetti | Pier Luigi Silvestrelli
Source: The Journal of Physical Chemistry (article, 2019-01-01)
Field: Materials Science — Materials Chemistry

Cooperative Effects of N-Doping and Ni(111) Substrate for Enhanced Chemical Reactivity of Graphene: The Case of CO and O₂ Adsorption While pristine graphene (G) is chemically inert, chemical doping is currently regarded as a leading strategy for fine-tuning both G electronic properties and reactivity toward adsorbed species. Following recent experimental work, we demonstrate that deposition of G on Ni(111) and introduction of N-based defects in the G lattice lead to cooperative effects, determining sizeable chemical reactivity toward CO adsorption. CO chemisorption is predicted on pyridinic-, pyrrolic-, and epoxy-like defects generated by N-ion bombardment, compatibly with the experiment. Comparison with O₂ adsorption further reveals selective reactivity of the defective system with respect to distinct gaseous moieties, thereby opening new pathways toward high-sensitivity CO sensors and controlled surface chemical reactions. Chemistry ; Reactivity (psychology) ; Adsorption ; Graphene ; Chemisorption ; Inert ; Substrate (aquarium) ; Doping ; Inorganic chemistry ; Chemical reaction ; Chemical modification ; Chemical engineering ; Organic chemistry ; Physical chemistry ; Materials science Graphene research and applications ; Advancements in Battery Materials ; Supercapacitor Materials and Fabrication
Authors: Stella M. Luo | Kellie A. Stellmach | Stella Ikuzwe | Dennis Cao
Source: ChemRxiv (preprint, 2019-06-07)
Field: Materials Science — Materials Chemistry

Redox-Active Heteroacene Chromophores Derived from a Non-Linear Aromatic Diimide This work describes a three-step chromatography-free protocol for the synthesis of a novel organic materialsbuilding block, dichlorinated mellophanic diimide (MDI), that is shown to undergo nucleophilic substitutionwith a variety of ortho disubstituted benzenes to yield a series of chromophores. Furthermore, 1,2,4,5-tetrasubstituted benzenes can be used to synthesize tetraimide heteropentacene derivatives endcapped byMDI motifs. The fine-tuning effects of heteroatom identity were investigated by UV-Vis and fluorescencespectroscopy, cyclic and differential pulse voltammetries, and density functional theory calculations. Oxidationof diamino MDI derivatives yields di- and tetraimide functionalized azaacenes with significantly lowered LUMOlevels (down to –4.49 eV), narrowed bandgaps (down to 1.81 eV), and high molar absorptivities (up to 84,000M–1 cm–1). Diimide ; Chromophore ; Chemistry ; Redox ; Density functional theory ; Yield (engineering) ; Nucleophilic substitution ; Nucleophile ; Photochemistry ; Polymer chemistry ; Computational chemistry ; Organic chemistry ; Molecule ; Materials science Luminescence and Fluorescent Materials ; Organic Electronics and Photovoltaics ; Conducting polymers and applications
Authors: Manfred F. Maitz | M. Cristina L. Martins | Niels Grabow | Claudia Matschegewski | Nan Huang | Elliot L. Chaikof | Mário A. Barbosa | Carsten Werner | Claudia Sperling
Source: SSRN Electronic Journal (article, 2019-01-01)
Field: Materials Science — Surfaces, Coatings and Films

The Blood Compatibility Challenge. Part 4: Surface Modification for Hemocompatible Materials: Passive and Active Approaches to Guide Blood-Material Interactions Compatibility (geochemistry) ; Engineering ; Computer science ; Materials science ; Composite material Polymer Surface Interaction Studies ; Electrospun Nanofibers in Biomedical Applications ; biodegradable polymer synthesis and properties
Authors: David Barker | Lisa I. Pilkington | Natalie A. Haverkate | Euphemia Leung | Jóhannes Reynisson
Source:  (article, 2019-08-06)
Field: Chemistry — Organic Chemistry

Development of Thienopyridines as Potent Antiproliferative Agents Virtual high throughput screening of a large compound library against the regulatory enzyme phospholipase C (PLC) led to the discovery of the thieno[2,3-b]pyridine-2-carboxamides as potential inhibitors. Subsequent biological testing verified the antiproliferative activity of this compound class. Morphology and motility assays, using a number of triple negative breast cancer cell lines, led to the conclusion that PLC is the most probable biomolecular target. Using a combination of computer-aided drug design and synthesis, further analogues have been prepared and tested for their antiproliferative activity, allowing a comprehensive SAR to be developed. Numerous analogues with low nano-molar growth inhibition against various cancers have been prepared. SAR studies suggest that the core structure can be fine-tuned to specific cancers, potentially due to enzyme/isoform specificity. Additionally, mouse xenograft assays showed significant reduction in tumour size after treatment, whilst showing no adverse effects to non-cancerous mice. Here, we report on our recent development of novel thienopyridines and derivatives, expanding the SAR against PLC, and our efforts to prepare potent, soluble, and bioavailable compounds. Chemistry ; Enzyme ; Virtual screening ; Drug discovery ; Cell growth ; High-throughput screening ; Pharmacology ; Computational biology ; Cancer research ; Biochemistry ; Biology Synthesis and biological activity ; Synthesis and Reactivity of Sulfur-Containing Compounds ; Synthesis and Reactivity of Heterocycles
Authors: Andrea B. Simões | Flávio Figueira | Ricardo F. Mendes | Jéssica S. Barbosa | João Rocha | Filipe A. Almeida Paz
Source: Acta Crystallographica Section E Crystallographic Communications (article, 2019-10-03)
Field: Chemistry — Inorganic Chemistry

One-dimensional ladder gallium coordination polymer A one-dimensional ladder-type coordination polymer, poly[[(μ<sub>2</sub>-hydroxido)(μ<sub>2</sub>-1<i>H</i>-pyrazole-3,5-di-carboxyl-ato)gallium(III)] monohydrate], [Ga(C<sub>5</sub>H<sub>2</sub>N<sub>2</sub>O<sub>4</sub>)(OH)(H<sub>2</sub>O)] <sub><i>n</i></sub> or [Ga(HPDC)(OH)(H<sub>2</sub>O)] <sub><i>n</i></sub> , <b>I</b>, isotypic with a V<sup>3+</sup> coordination polymer previously reported by Chen <i>et al.</i> [<i>J. Coord. Chem.</i> (2008). <b>61</b>, 3556-3567] was prepared from Ga<sup>3+</sup> and pyrazole-3,5-di-carb-oxy-lic acid monohydrate (H<sub>3</sub>PDC·H<sub>2</sub>O). Compound <b>I</b> was isolated using three distinct experimental methods: hydro-thermal (HT), microwave-assisted (MWAS) and one-pot (OP) and the crystallite size should be fine-tuned according to the method employed. The coordination polymeric structure is based on a dimeric Ga<sup>3+</sup> moiety comprising two μ<sub>2</sub>-bridging hydroxide groups, which are inter-connected by HPDC<sup>2-</sup> anionic organic linkers. The close packing of individual polymers is strongly directed by the supra-molecular inter-actions, namely several O-H⋯O and N-H⋯O hydrogen-bonding inter-actions. Chemistry ; Moiety ; Coordination polymer ; Crystallography ; Supramolecular chemistry ; Gallium ; Hydrogen bond ; Polymer ; Pyrazole ; Stereochemistry ; Hydrothermal synthesis ; Hydrothermal circulation ; Crystal structure ; Molecule ; Organic chemistry ; Chemical engineering Metal-Organic Frameworks: Synthesis and Applications ; Magnetism in coordination complexes ; Crystal structures of chemical compounds