Materials Literature
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This article examines the effects of dispersed phase concentration, processing apparatus, viscosity ratio, and interfacial compatibilization using an SAN–amine compatibilizer on the morphology of blends of bisphenol A–polycarbonate (PC) with styrene–acrylonitrile (SAN) copolymers. For uncompatibilized blends, the disp…
Liquid crystalline 1,1′∶4′,1″-terphenyls with three and four lateral fluoro substituents and alkyl or alkoxy substituents in the 4- and 4′-positions have been synthesised. Synthetic strategies employed were convergent and involved the use of arylboronic acids and aryl halides in palladium-catalysed cross-coupling reac…
A diradical consisting of two polychlorinated triphenylmethyl radical units connected by a 1,1′-metallocenylendivinylene bridge has been synthesized and characterized; EPR frozen solution experiments down to liquid helium temperature showed that the organometallic unit acts as a ferromagnetic coupler.
Structure, magnetic and transport properties of manganites have been studied. Samples with show ferromagnetic behaviour. For higher concentrations an important influence of antiferromagnetic interactions has been observed. The sample shows an antiferro-ferromagnetic transition induced by the applied field and the comp…
A new model which extends previous studies and includes the interaction between enveloping gas and an array of droplets has been developed and presented in a previous paper. The model incorporates the probability density function of atomized metallic droplets into heat transfer equations. The main thrust of the model…
In situ XAFS spectroelectrochemistry is used to characterize the oxidation state and coordination environment of cerium in two different heteropolytungstates, the Wells–Dawson [Ce(α-2-P2W17O61)2]17– anion, and the Preyssler [CeP5W30O110]12– anion. Ce(III), coordinated to the Wells–Dawson framework, is oxidized at an a…
The self-associated structures of two noble meso-(monopyrazolyltritolyl)porphyrins synthesized via their NH-protected precursors have been studied by 1H NMR, FT-IR and ESI MS measurements; meso-(pyrazol-4-yl)porphyrin and meso-(3,5-dimethylpyrazol-4-yl)porphyrin form a dimer and a tetramer, respectively, in solution d…
The volume changes of poly(2‐methylaniline) upon redox cycling in different acidic media was studied using voltammetric experiments with simultaneous microscopic observation. These experiments were performed during continuous potential cycling and also when the polymer film was completely reduced and relaxed. The chan…
The zero-field ${}^{139}\mathrm{La}$ nuclear magnetic resonance (NMR) was studied in polycrystalline ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}$ for $0.125<~x<~0.5$ to investigate magnetic phases in ordered states. The main result of this work is that mixed states are found near any pha…
The field distribution of DC insulation systems is controlled by the conductivity κ of the insulation material. It can be improved by using a high resistance surface coating. Furthermore this coating can prevent charge accumulation on the surface of the insulation. This paper reports about the investigations regarding…
The 1H NMR spectra of the 5,10,15,20-tetraalkylporphyrins 2–4 reveal a large downfield shift of the signal for the NH protons and a reduction in the activation energy for NH tautomerism as the alkyl substituents become larger; these unusual changes can be rationalized in terms of greatly enhanced intramolecular hydrog…
Separation of methylalumoxane (MAO) by adsorption on siliceous porous materials with different average pore diameters has been carried out; polymerization of ethylene was conducted with Cp2ZrCl2 using the separated MAO as cocatalyst, it was found that the MAO adsorbed on MCM-41 with average pore size of ca. 25 Å is ve…
Abstract New materials derived from metathesized soybean oil have been prepared and characterized. Thermal polymerization of metathesized soybean oil in the presence of air results in yellow, brittle gels. These materials display a curious tendency to produce audible popping sounds when exposed to chlorinated organic…
The “silica garden’', an amorphous aluminosilicate produced from a solution of sodium silicate seeded with crystalline aluminium nitrate, has been examined by FTIR, TGA, solid-state NMR and catalytic testing. The silica garden is a Brønsted acid catalyst and we characterize its porosity, acidity and catalytic activity…
Design and optimization of high-frequency magnetic components usually involve a number of tradeoffs between performance functions. This paper investigates the relationships between some of these factors by direct implementation of the thermal reference model previously presented by the authors. This unique thermal mod…
A method to estimate precise iron loss in an electrical machine is presented. This method implements a 2D finite element simulation of moving structure including the non-linear magnetic behaviour and a new dynamical hysteresis model of the magnetic circuit. The 2D finite element simulation is used to evaluate the indu…
Chiral nematic liquid crystal compositions containing mono- and di-acrylates in mixtures with non-reactive liquid crystal molecules were produced. Defect-free planar macroscopic alignment of the molecules was induced between uniaxially rubbed substrates. Polymerization of the acrylate groups was initiated photochemica…
This paper reviews some relevant citations regarding the non-specific forces that must be considered in oral bioadhesive events. These range from forces related to restorative dentistry to those related to prevention and molecular biology. Types of interactions discussed are: 1. Van der Waal's forces; 2. electrostatic…
Several new members (n = 2, 3, 4 members) of the family of layered perovskites Li2[AxBnO3n + 1] (A = Ca, Sr, La; B = Nb, Ta, Ti, Fe) have been synthesized for the first time. The structure analysis of Li2SrNb2O7 and Li2SrTa2O7 determined by powder X-ray diffraction (XRD), and of Li2La1.78Nb0.66Ti2.34O10 and Li2Sr2Nb3.…
Monolayers of the amphiphile 1-monopalmitoyl- rac -glycerol at the air−water interface assemble into domains in which the molecular tilt azimuth is organized into star-shaped patterns. When the domains are transferred to solid supports as Langmuir−Blodgett films, they are capable of producing a macroscopic azimuthal o…