Epitaxial superconducting δ-MoN films grown by a chemical solution method

The synthesis of pure δ-MoN with desired superconducting properties usually requires extreme conditions, such as high temperature and high pressure, which hinders its fundamental studies and applications. Herein, by using a chemical solution method, epitaxial δ-MoN thin films have been grown on c-cut Al(2)O(3) substrates at a temperature lower than 900 °C and an ambient pressure. The films are phase pure and show a T(c) of 13.0 K with a sharp transition. In addition, the films show a high critical field and excellent current carrying capabilities, which further prove the superior quality of these chemically prepared epitaxial thin films.     

Resolution and identification of co‐eluting alkylphenols in comprehensive two‐dimensional gas chromatography–mass spectrometry by multivariate curve resolution‐alternating least squares

The interest in the analysis of alkylphenols (APs) has widely increased in the last decades because of the endocrine disrupting features of these phenol derivatives. However, the isolation and identification of many of the multiple chemical structures of all APs is a very challenging task because of their similar physicochemical properties. In this work, the co‐elution of the isomers present in technical mixtures and using comprehensive two‐dimensional gas chromatography coupled to quadrupole mass spectrometry was resolved using multivariate curve resolution‐alternating least squares algorithm. The mass spectrum of each resolved compound was compared with the theoretical mass spectrum obtained from the literature, in order to assign the appropriate identification of each isomer. Two commercial mixtures were studied; in one of them, 34 compounds were resolved, and in the second mixture, 40 compounds were resolved. The relative abundances of the compounds were also calculated in both mixtures. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis and spectroscopic characterization of 1-[1,2,3-triazol-1-yl]-4-aroylazetidin-2-ones

1-(N-Phenacylidene)amino-1,2,3-triazoles 3 react with propionylchloride and phenoxyacetylchloride in the presence of triethylamine to give trans- ( 5 ) and cis- ( 6 ) 1-(1,2,3-triazol-1-yl)-4-aroylaztidin-2-ones in a 1:1 ratio, on the contrary to the 1-(N-arylidene)amino-1,2,3-triazoles, which do not give any reaction product with the same acid chlorides. The spectroscopic characteristics of these new N-triazolyl-β-lactams are also discussed.     

Improvement of Impact Strength of Polylactide Blends with a Thermoplastic Elastomer Compatibilized with Biobased Maleinized Linseed Oil for Applications in Rigid Packaging

This research work reports the potential of maleinized linseed oil (MLO) as biobased compatibilizer in polylactide (PLA) and a thermoplastic elastomer, namely, polystyrene-b-(ethylene-ran-butylene)-b-styrene (SEBS) blends (PLA/SEBS), with improved impact strength for the packaging industry. The effects of MLO are compared with a conventional polystyrene-b-poly(ethylene-ran-butylene)-b-polystyrene-graft-maleic anhydride terpolymer (SEBS-g-MA) since it is widely used in these blends. Uncompatibilized and compatibilized PLA/SEBS blends can be manufactured by extrusion and then shaped into standard samples for further characterization by mechanical, thermal, morphological, dynamical-mechanical, wetting and colour standard tests. The obtained results indicate that the uncompatibilized PLA/SEBS blend containing 20 wt.% SEBS gives improved toughness (4.8 kJ/m²) compared to neat PLA (1.3 kJ/m²). Nevertheless, the same blend compatibilized with MLO leads to an increase in impact strength up to 6.1 kJ/m², thus giving evidence of the potential of MLO to compete with other petroleum-derived compatibilizers to obtain tough PLA formulations. MLO also provides increased ductile properties, since neat PLA is a brittle polymer with an elongation at break of 7.4%, while its blend with 20 wt.% SEBS and MLO as compatibilizer offers an elongation at break of 50.2%, much higher than that provided by typical SEBS-g-MA compatibilizer (10.1%). MLO provides a slight decrease (about 3 °C lower) in the glass transition temperature (T_g) of the PLA-rich phase, thus showing some plasticization effects. Although MLO addition leads to some yellowing due to its intrinsic yellow colour, this can contribute to serving as a UV light barrier with interesting applications in the packaging industry. Therefore, MLO represents a cost-effective and sustainable solution to the use of conventional petroleum-derived compatibilizers.     

Experimental Determination of the Electronic Polarizability of Quinoline and Isoquinoline in Solution by Three New Strategies

The values of electronic polarizability of quinoline and isoquinoline in extremely diluted liquid solution are reported in this paper. These were obtained by means of three new strategies based on UV-visible-NIR spectroscopy, the Kramers-Krönig relations, high precision densitometry and high exactitude refractometry, which are called here Arakawa’s Approximation (AA), Optical Substractive Approximation (OSA) and Optical Differential Approximation (ODA). In general the static electronic polarizability values of solute molecules obtained by ODA and OSA are in excellent agreement with the reported theoretical values at the Density Functional Theory (DFT) level and the Atom monopole-dipole model, but strong discrepancies were observed with the experimental values previously reported for quinoline and isoquinoline using refractometric and electro-optic methods. These differences were interpreted and analyzed in terms of dielectric intermolecular forces, resonant and pre-resonant effects. The AA method is shown to fail in predicting the polarizability of the quinoline and isoquinoline molecules.     

Synthesis and mass spectra of some 1-aroylamino-5-arylaminomethyl-1,2,3-triazoles

The title compounds 2 are prepared from the reaction of 1-(N, N-diaroyl)amino-5-bromomethyl-1,2,3-triazoles with aromatic amines. The fragmentation pattern upon electron impact at 70 eV of compounds 2 is studied. The molecular ion peak is present in all the spectra examined. Besides the [M-28]⁺⁺, there is also a more abundant [M-29]⁺ peak, corresponding to a N₂H loss of the molecular ion. The ion Ar²NH = CH₂ is the base or the most prominent peak.     

Dipolar relaxations in the glass transition region and in the liquid crystalline phase of two side-chain liquid crystalline polysiloxanes

The molecular relaxation mechanisms in the glass transition region and in the liquid crystalline phase exhibited by two side-chain liquid crystalline polysiloxanes have been studied by Thermally Stimulated Discharge Currents. These results were compared with those previously obtained by dielectric relaxation spectroscopy. It was observed that two relaxation mechanisms were present in the liquid crystalline phase, and we suggest that these might correspond to the motions of the mesogenic moieties in the liquid crystalline phase. © 1996 John Wiley & Sons, Inc.     

On-Line Multicomponent Determination of the Flux of Mixtures of Phenols Through a Liquid Membrane in Real Time

 The analysis of mixtures of four phenolic compounds in an on-line system using UV-visible measurements with a fibre optic probe is discussed in this work. The aim of this system is to provide accurate real time concentration profiles in order to monitor the transport of phenols across a solid supported liquid membrane in both the feed and stripping phases. Different calibration models are taking into account the pH of the solution, using experimental designs and the first derivative in combination with different multivariate approaches like multiple linear regression (MLR), inverted least squares (ILS) and partial least squares regression (PLS). The comparison of all these combinations is carried out by means of the predictive residual error sum of squares (PRESS) evaluated from an independent set of spectra. From this comparison it is concluded that a PLS model using first derivative spectra offers the most accurate and robust prediction in the permeation experiments. Additionally, the stability of the model and the figures of merit obtained are also discussed. Received July 22, 1999. Revision October 23, 2000.