Miracle-dz/UniFAR-FTUs huggingface dataset:
ZnO 1D nanostructures designed by combining atomic layer deposition and electrospinning for UV sensor applications

We explored for the first time the ability of a three-dimensional polyacrylonitrile/ZnO material prepared by a low-cost and scalable synthesis method based on the combination of electrospinning and atomic layer deposition (ALD) as a new material with a large surface area to enhance the performance of UV photodetection. The UV photoresponse current was enhanced by a factor of 250 compared to a flat electrode. In addition an increase by a factor of 1.3 of the recovery time has been observed which is negligible versus the huge amount of current enhancement. The greatly improved performance and the good stability of these nanostructured electrodes induce exciting materials for use in UV sensor applications.
Polymers for organic photovoltaics based on 1,5-bis(2-hexyldecyloxy)-naphthalene, thiophene, and benzothiadiazole

Two new conjugated polymers consisting of the donors 1,5-bis(2-hexyldecyloxy)naphthalene, thiophene, or bithiophene and the acceptor benzothiadiazole has been synthesized and their optical and photovoltaic properties have been characterized. The two polymers were compared with earlier synthesized and characterized polymers containing benzene instead of naphthalene. The two polymers absorb light in the visible spectrum (400 to 700 nm). The naphthalene containing polymers had blueshifted absorption spectra compared to the benzene containing polymers and also higher band gaps. In photovoltaic devices the bithiophene containing polymer gave the best efficiency of 0.6%, whereas the single thiophene only showed efficiency of 0.005%. This is lower than the best benzene incorporated polymer that showed efficiency up to 2.2%.
Retrieval of Aerosol Complex Refractive Index by Combining Cavity Ring Down Aerosol Spectrometer Measurements with Full Size Distribution Information

Cavity ring down aerosol extinction measurements are combined with size distribution measurements to provide a multi-parameter basis for the retrieval of the aerosol complex refractive index. We show that two distinct size distributions of small particles (< 300 nm) suffice to obtain robust convergence of the Mie theory fit of the extinction function. Experiments are performed both for purely scattering and for absorbing aerosol. Thus this method provides a perspective to use cavity ring down aerosol spectroscopy in field and laboratory measurements that often suffer from low particle concentrations and a lack of large particles.
Multiple-data-set Rietveld analysis using isotopes in powder neutron diffraction. I. Accurate determination of the doping level in the ternary system NixMg1-xO, 0.005 < x < 0.1

The use of isotopes to extract precise and very accurate structural information in complex Rietveld analysis has been demonstrated by comparison of results obtained for single-data-set analysis with those from multiple-data-set single-crystallographic-model analysis of NixMg1−xO doped with various nickel isotopes. Fractional occupancies of dopants can be accurately determined down to at least the 0.5% doping level, which cannot be obtained through single-sample-data-set refinements because of correlation effects, even when a large contrast exists between the nickel isotope used and magnesium.
Study of an Efficient and Selective Bromination Reaction of Substituted Thiophenes

Abstract Bromination in concentrated solutions of substituted thiophenes in acetic acid with NBS at room temperature was studied. Under the conditions, bromination readily took place with high regioselectivity at the 2-ring positions, > 99 %. The developed method was demonstrated to be suitable for multimolar preparations.
Isothermal transitions of a thermosetting system

A study of the curing reactions of a cycloaliphatic epoxy resin/anhydride system by torsional braid analysis showed the existence of two critical isothermal temperatures. These are Tg∞ (the maximum glass transition temperature of the thermoset system) and Tgg (the glass transition temperature of the material at its gel point). Two rheologically active kinetic transitions occur during isothermal cure which correspond to gelation and vitrification. Three types of isothermal behavior occur: if Tcure > Tg∞, only gelation is observed; if Tg∞ > Tcure > Tgg, both gelation and vitrification are observed; if Tcure < Tgg, only vitrification is observed. Tgg corresponds to the isothermal cure temperature at which gelation and vitrification occur simultaneously. Methods for determining the time to gel and the time to vitrify, and also Tg∞ and Tgg, have been developed. The time to gel obeyed the Arrhenius relationship; the time to vitrify passed through a minimum. Application of these results to thermosetting systems in general is discussed in terms of the influence of molecular structure on the values of Tg∞ and Tgg.
Synthesis, characterization, and hydrolytic degradation of graft copolymers of polystyrene and aliphatic polyesters

In the present study, a new class of biodegradable graft copolymers of polystyrene (PS) with aliphatic polyester (APE) side chains were synthesized through combination of nitroxide-mediated free radical polymerization (NMRP) and ring-opening polymerization (ROP) with copper (I)-catalyzed ‘click’ chemistry. First, the click component, azido-functional PS (PS-N3) was prepared by copolymerization of styrene and chloromethyl styrene by NMRP followed by the conversion of chlorine groups of the resulting copolymer to azido groups by using NaN3 in N,N-dimethylformamide. Propargyl functional APEs were prepared independently by ROP of lactic acid and glycolic acid using tin octoate in the presence of propargyl alcohol at 130 °C. Finally, PS-N3 was coupled with the resulting polymers by click chemistry to yield graft copolymers (PS-g-poly (L-lactic-co-glycolic acid) [PLLA] and PS-g-PLLGA, respectively). The intermediates and final graft copolymers were characterized by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectral and gel permeation chromatography analyses. The hydrolytic degradation behavior of the obtained graft copolymers in phosphate buffer saline solution were investigated by the weight loss and molecular weight measurements. It is shown that both copolymers undergo slow hydrolytic degradation, PS-g-PGLLA being relatively faster due to the presence of hydrophilic glycolic acid groups in the structure.
Structure, Characterization and ab Initio Calculations of [Mn(4,4´-bipy)2(H2O)4][HOOCC6H4SSC6H4COO]2

The title compound was obtained by reaction of MnCl2 · 4H2O, NH3·H2O, 4,4′-bipyridine, and 2,2′-dithio-bis(benzoic acid) (H2-DTBB) in aqueous solution. It was characterized by single crystal X-ray crystallography, elemental analysis and IR spectroscopy. The compound is composed of one [Mn(bipy)2(H2O)4]2+ cation and two H-TDBB1− anions, where Mn2+ adopts an octahedral geometry and is coordinated by four water oxygen atoms and two N atoms of 4,4′-bipyridine ligands. The [Mn(bipy)2(H2O)4]2+ cations are linked into one-dimensional chains by O-H· · ·N hydrogen bonds. These cationic chains are further organized into a two-dimensional network with the H-TDBB1− anions through hydrogen bonds.
Synthesis and Characterization of Biodegradable Poly(lactic-co-glycolic acid)

A series of poly(lactic-co-glycolic acid) (PLGA) was synthesized by bulk ring-opening copolymerization with different ratios of L-lactic acid (L-LA) to glycolic acid (GA); stannous octoate [Sn(Oct)2] was used as catalyst. The structures were characterized by FT-IR. The crystallinity and the glass-transition temperature (Tg) were studied by differential scanning calorimeter (DSC). Tg decreased with the increase of GA and the rate of degradation and degree of hydrophilicity increased with the increased content of GA.
Bipolaron anisotropic flat bands, Hall mobility edge, and metal-semiconductor duality of overdoped high-Tc oxides.

Hole bipolaron band structure with two flat anisotropic bands is derived for oxide superconductors. Strong anisotropy leads to one-dimensional localization in a random field which explains the {ital metal}-{ital like} value of the Hall effect and the {ital semiconductorlike} doping dependence of resistivity of overdoped oxides. Doping dependence of {ital T}{sub {ital c}} and {lambda}{sub {ital H}}(0) as well as the low-temperature dependence of resistivity, of the Hall effect, {ital H}{sub {ital c}2}({ital T}) and robust features of angle-resolved photoemission spectroscopy of several high-{ital T}{sub {ital c}} copper oxides are explained. {copyright} {ital 1996 The American Physical Society. }
Network density control in epoxy–silica hybrids by selective silane functionalization of precursors

Following previous work on the compatibilization of organic–inorganic hybrids through coupling reactions with the precursor components, the present study evaluates the relative efficiency of different types of coupling agents on the morphology and properties of epoxy–silica hybrids. In particular, this investigation compares the effects of introducing trialkoxysilane functional groups at the chain end (using amine- and mercapto-silanes) with similar types grafted in the middle of the chain of the constituent resin (using an isocyanate silane). The use of coupling agents with a basic character (amine silane type) brings about the formation of denser networks in both constituent phases of the resulting epoxy–silica hybrid, which is manifest through a large increase in the Tg and a more extensive suppression of the molecular relaxations within the glass transition regions. Increasing the number of alkoxysilane functional groups at the chain end, with the use of a bis-aminosilane, has a relatively minor effect on the morphology and dynamic mechanical spectra of the resulting epoxy–silica hybrids. It was also found that while the incorporation of small amounts of a high molecular weight epoxy resin causes considerable plasticization of the organic phase, much larger amounts of organic (aliphatic) co-agent within the siloxane phase are required to deteriorate those properties that are related to the inorganic character of the hybrid material. © 2005 Wiley Periodicals, Inc. Adv Polym Techn 24:91–102, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20033
Preparation, characterization, and properties of poly(aryl ether sulfone) systems with double‐decker silsesquioxane in the main chains by reactive blending

A series of copoly(aryl ether sulfone)s containing double-decker-shaped silsesquioxane (DDSQ) in the main chain was prepared. Toward this end, a novel diphenol polyhedral oligomeric silsesquioxane macromer was synthesized by hydrosilylation between 3,13-dihydro octaphenyl double-decker silsesquioxane (denoted dihydro DDSQ) and eugenol. The poly(aryl ether sulfone)s were synthesized from diphenol DDSQ, bisphenol A (BPA), and 4-fluorophenyl sulfone using a one-step high-temperature solution method. By adjusting the ratio of diphenol DDSQ to BPA, copolymers with variable DDSQ content in the main chains were obtained. With increased DDSQ content in the main chain, the glass transition temperature decreased based on differential scanning calorimetry, and anti-degradation was enhanced based on thermogravimetric analysis. Moreover, the dielectric constant κ of pure polymer (3.19 at 1 MHz) initially increased to 4.04 (DDSQ molar ratio = 10%), and then decreased to 2.68 at 1 MHz (DDSQ molar ratio = 100%). Crystallization behavior, solubility, and surface hydrophobicity were also investigated. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 780–788
Lithium chloride solution as an extraction agent for soils

The author proposes the extraction of mobile (”available”) ions including heavy metals by means of a 0.4 M solution of LiCl. The accuracy and precision of the method are demonstrated and the results compared with the CaCl2 and BaCl2 extraction. The suspension pH of non-calcareous samples remains almost constant during LiCl-extraction but changes considerably with NH4NO3- and NH4-acetate. The results of the LiCl- and the CaCl2-extraction were closely correlated. The same was true for the relative cation distribution on the sorption complex compared to the BaCl2-extraction. A series of arguments emphasize and substantiate the advantages of the use of neutral salts, especially LiCl, for extraction. Lithiumchloridlosung als Boden-Extraktionsmittel Zur Extraktion der beweglichen („verfugbaren“) Ionen ein-schlieslich der Schwermetalle wird 0,4 M LiCl-Losung vorgeschlagen. Richtigkeit und Prazision der erhaltenen Ergebnisse werden uberpruft und mit der CaCl2- und BaCl2-Extraktion verglichen. Es zeigt sich, dass der Boden-pH wahrend der LiCl-Extraktion annahernd konstant bleibt, wahrend es sich durch die Extraktion mit NH4NO3 und NH4-Acetat-Losung bei den kalkfreien Boden deutlich verandert. Es ergeben sich hohe Korrelationen der Ergebnisse zwischen dem LiCl- und CaCl2-Extrakt, sowie zwischen der relativen Kationenverteilung am Sorptionskomplex auch im Vergleich zur BaCl2-Extraktion. Der Vorteil von Neutralsalzextraktionen, insbesondere mit LiCl, wird hervorgehoben und begrundet.
Investigation of the optical properties of organic-inorganic hybrid polymers by IR to Vis-fUV spectroscopic ellipsometry

Inorganic-organic hybrid polymers are used as barrier coatings in order to protect flexible electronic devices from the permeation of atmospheric oxygen and water vapour that induce oxidation to the Flexible Electronic Device (FED) organic layers, reducing their operation, efficiency and stability. In this work, Spectroscopic Ellipsometry (SE) in a wide spectral region, from the infrared (IR) (900–4000 cm–1) to the Vis-far UV (1.5-6.5 eV) has been implemented in order to investigate the optical properties of different types of hybrid polymers, which are synthesized via the sol–gel technique onto Polyethylene Terephthalate (PET), SiOx/PET and AlOx/PET substrates. The analysis of the measured SE spectra revealed valuable information about the electronic and vibrational response as well as the cross-linking mechanisms that control the interface and barrier properties of these materials. Finally, the correlation of the optical properties with the synthesis parameters and the barrier response of these materials will significantly contribute towards their optimization in order to be used as high barrier coatings. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Monte Carlo Study on the Water Meniscus Condensation and Capillary Force in Atomic Force Microscopy

The water meniscus condensed between a nanoscale tip and an atomically flat gold surface was examined under humid conditions using grand canonical Monte Carlo simulations. The molecular structure of the meniscus was investigated with particular focus on its width and stability. The capillary force due to the meniscus showed a dampened oscillation with increasing separation between the tip and surface because of the formation and destruction of water layers. The layering of water between the tip and the surface was different from that of the water confined between two plates. The humidity dependence of the capillary force exhibited a crossover behavior with increasing humidity, which is in agreement with the typical atomic force microscopy experiment on a hydrophilic surface.
LINEAR FREE ENERGY RELATIONSHIPS CONCERNING EQUILIBRIA IN MODERATELY CONCENTRATED MINERAL ACIDS: A SIMPLE METHOD FOR ESTIMATING pK's OF WEAK BASES

Linear relationships exist between the logarithms of equilibrium quotients, [SH+]/[S][H+], of diverse bases as they vary with acid concentration in moderately concentrated mineral acids. For purposes of formulating these linear free energy relationships in standard form, the equilibrium quotient for protonation of a hypothetical aromatic primary amine of pKa zero has been chosen as horizontal coordinate; this is given by (−H0 − log [H+]). Log ([SH+]/[S]) + H0 is plotted against (H0 + log [H+]). The slope, of the linear plot is a parameter which characterizes the response of the equilibrium quotient to changing acid concentration. The intercept represents the thermodynamic pKa of the base. This constitutes a general method for estimating the pKa of any base which undergoes protonation in moderately concentrated mineral acid, with reference to the single acidity function, H0. For bases of diverse type, pK's estimated by this method are in good agreement with those estimated by the acidity function method. U.
Drug Screening Using Microextraction in a Packed Syringe (MEPS)/Mass Spectrometry Utilizing Monolithic‐, Polymer‐, and Silica‐Based Sorbents

Abstract Micro extraction in packed syringe (MEPS) has been evaluated for drug and metabolites screening online with mass spectrometric detection. In this study, silica based (C8), polymer based (ENV+), and a methacrylate based organic monolith were used as sorbents for MEPS. Monolithic material has shown to be an effective chromatographic support for the separation of several classes of compounds. In this study, the focus is subdivided into three parts: 1) Using MEPS for drugs and metabolites screening, 2) Preparation of a monolithic material in situ in a syringe, and 3) Comparison of the monolith, ENV+, and C8 as sorbent material. The synthesis of the monolithic material was by radical polymerization of glycidyl methacrylate (GMA), ethylene glycol dimethacrylate (EGDMA), and butyl methacrylate (BMA) in porogenic solvent 1‐dodecanol and cyclohexanol. An 8 µL of the synthesized material was drawn into a 250 µL syringe and thermally polymerized at 57°C for 24 h. Individual syringes containing the monolithi.
Hybrid solution processed InGaO3(ZnO)m thin films with periodic layered structures and thermoelectric properties

Short period superlattices comprising alternating InO2− and GaO+(ZnO)2 layers were fabricated by a simple hybrid solution process and reactive solid-phase epitaxy at high temperature. The epitaxial ZnO buffer layer deposited by sputtering, and an amorphous IGZO layer fabricated from a solution mixture of 1 : 1 : 1.0 (In nitrate : Ga nitrate : Zn acetate) produced pure, single-phase InGaO3(ZnO)2 films with a well-ordered layered structure and smooth surfaces, which showed intense periodic diffraction peaks. Deviation from the stoichiometric sol condition induced coexisting InGaO3(ZnO)2 and other InGaO3(ZnO)m phases and very rough surface morphologies. The solid-phase epitaxy of a single phase decreased electrical resistivity, increased the Seebeck coefficient, and significantly improved the power factor. An extremely low thermal conductivity (1.11 W m−1 K−1) was also obtained due to phonon scattering at the InO2− and GaO+(ZnO)2 interfaces by the formation of the superlattice structure. This solution-based fabrication of superlattice structures could aid the development of advanced multicomponent oxides due to its simple growth process and the adaptability of compositions.
Biocatalytic Route to Ascorbic Acid‐Modified Polymers for Free‐Radical Scavenging

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The Effect of Heating In Vacuo on the Microporosity of Sepiolite

The t-plot method has been applied to the results of nitrogen adsorption at 76°K on sepiolite first heated in vacuo at various temperatures. Heating sepiolite samples in vacuo at 427°K results in a large decrease in surface area compared with samples outgassed at 373°K. A change in structure and a consequent collapse of micropores is postulated. However, the t-plots indicate that some microporosity remains. Outgassing at 623°K appears to destroy completely the micropores.
The Laboratory Characterization of Jet Fuel Vapor and Liquid

Jet fuel (Jet A, Jet A1) was characterized using two gas chromatographic techniques. Headspace gas chromatography (HS-GC) was used to determine component partial pressures and total vapor pressures by measuring vapor densities in equilibrium with the liquid fuel. Component partial pressures and total vapor pressures were also derived from analysis of the neat jet fuel liquid by determining liquid component mole fraction and using this result with Raoult's law to calculate vapor pressure. Measurements of some of the fuel vapor samples were made at 40, 50, and 60 °C and at vapor volume-to-liquid volume (V/L) ratios of 274 and 1.2, representing, respectively, a nearly empty (2.9 kg/m3) and a half-filled (364 kg/m3) center wing tank (CWT) in a Boeing 747-100 series aircraft. The temperatures and V/L ratios were chosen to cover the range of conditions that could exist in the CWT under some aircraft operations. Measurements of other fuel vapor samples were made at the individual fuel flash point temperatures (V.
Use of One‐Parameter Models for the Assessment of Particle Interactions by photon correlation spectroscopy

The use of very simple one-parameter models of particle interactions for the analysis of the concentration dependence of the collective diffusion coefficient as determined by photon correlation spectroscopy is illustrated by measurements on two different systems. In one, a micro-emulsion, attractive interactions are dominant whereas in the other, a silica dispersion, repulsive interactions play the major role.
Magnetic Copper Ferrite Nanoparticles: An Inexpensive, Efficient, Recyclable Catalyst for the Synthesis of Substituted Benzoxazoles via Ullmann-Type Coupling under Ligand-Free Conditions

Abstract A new sustainable strategy for the synthesis of benzoxazoles from substituted N-(2-halophenyl)benzamides was developed in which inexpensive, readily available, air-stable, recyclable copper(II) ferrite serves as a nanocatalyst. The nanocatalyst can be completely recovered with an external magnet and can be used seven times without significant loss of catalytic activity.
Synthesis of Cerium Oxide Nanoparticles by the Precipitation Method

Cerium oxide nanoparticles with sphere-like in shape were synthesized by precipitation method, using cerium nitrate as raw material and ammonium acid carbonate as precipitation agent. Effects of reactant concentration, supersonic wave and dispersant agent on properties of the cerium oxide particles were investigated. Experimental results showed that the dispersant agent played important roles on the size of resulting particles. Besides, supersonic wave prevented the precipitate from agglomerateing partially.