Materials Literature
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[reaction: see text] The utility of expanded porphyrins as a dipolarophile in cycloaddition reactions has been investigated. The 1,3-dipolar cycloaddition of meso-octakis(pentafluorophenyl)[36]octaphyrin(1.1.1.1.1.1.1.1) with an azomethine ylide provides mono- and bis-pyrrolidine-fused octaphyrins regio- and stereosel…
The reaction of aerosol droplets of the organoborate reagent (MeO) 3 B, suspended in nitrogen, with gaseous ammonia in a flight tube heated to 800−1500 °C was used to produce, in high yield, spherical morphology precursor powders BN x O y C z that contain decreasing amounts of oxygen and carbon as the process temperat…
New techniques are presented for the preparation of iodine derivatives, involving vapour diffusion of iodine. Firstly, in the vaporizing iodine labelling (VIL) technique, a small amount of KI/I(2) solution is enclosed in a crystallization well, with the result that gaseous I(2) molecules diffuse into the crystallizati…
The structural and catalytic properties of SiO2- and TiO2 -supported Pt-Au bimetallic catalysts prepared by coimpregnation were compared with those of samples of similar composition synthesized from a Pt2Au4(C{triple bond}CBut)8 cluster precursor. The smallest metal particles were formed when the bimetallic cluster wa…
Equal channel angular extrusion or pressing (ECAE or ECAP) is a process used in order to impart severe plastic deformations to processed materials with the aim of improving their mechanical properties by reducing the grain size. The grain size reduction leads to mechanical properties improvement. In the present study,…
The crystal structure and thermal properties of La 1 - x Ca x CoO 3 - δ have been investigated by thermogravimetrical analysis and high-temperature X-ray diffraction in air and N 2 . La 1 - x Ca x CoO 3 - δ is oxygen deficient at ambient temperature, and the oxygen nonstoichiometry increases with Ca content, temperatu…
The mapping of enthalpy landscapes is complicated by the coupling of particle position and volume coordinates. To address this issue, we have developed a new split-step eigenvector-following technique for locating minima and transition points in an enthalpy landscape at absolute zero. Each iteration is split into two…
Mesh size distributions (MSDs) of swollen cross-linked styrene copolymer networks have been measured by thermoporometry using CCl(4) as a probe liquid. All numerical relationships required for the calculation of the MSD were established for both the liquid-to-solid and the solid-to-solid thermal transitions of CCl(4)…
Abstract Biocompatible and easily available materials from dairy production waste were used for modification of water‐soluble polymeric blends of Poly(vinyl alcohol) (PVA) and Poly(vinyl pyrrolidone) (PVP). The resulting biocomposites of PVA/PVP with various concentrations of lactose (L) or calcium lactate (CL) (0, 5,…
High surface area ceria nanoparticles have been prepared using a citrate solgel precipitation method. Changes to the particle size have been made by calcining the ceria powders at different temperatures, and X-ray methods used to determine their lattice parameters. The particle sizes have been assessed using transmiss…
Over the last decade techniques such as confocal light microscopy, in combination with fluorescent labelling, have helped biologists and life scientists to study biological architectures at tissue and cell level in great detail. Meanwhile, obtaining information at very small length scales is possible with the combinat…
The $2644.5\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ vibrational line observed in ZnO grown by the hydrothermal method and doped with D impurities is split into two components with intensities consistent with the natural abundances of $^{6}\mathrm{Li}$ and $^{7}\mathrm{Li}$, unambiguously establishin…
Abstract Currently, intense research is underway to develop polymer nanocomposites because of their numerous potential applications. However, the uniform dispersion of inorganic nanoparticles in polymer nanocomposites without an additional chemical phase has proved to be a difficult challenge. In this paper, we presen…
In this article, we describe a method to create rough features on silicon surfaces by reactive etching of a photoresist layer. The roughness and, consequently, the wettability of the surfaces can be modified by modifying the duration of plasma etching. Hydrophobic materials deposited on the rough silicon surface can b…
A series of M-type hexaferrite samples with composition Sr1−xLaxFe12O19 (x = 0.00, 0.05, 0.15 and 0.25) were prepared by standard ceramic technique. AC electrical conductivity measurements were carried out at different frequencies (20 Hz–1 MHz) and at different temperatures. The dielectric constant and dielectric loss…
Zinc oxide is an important group II-VI semiconductor material with optical properties that permit stable emission at room temperature. We report on the synthesis of highly uniform nanocrystalline ZnO tetrapod (ZnO-T) nanostructures through a modified chemical vapour transport process. These self assembled nanocrystals…
Structural proteomics has promoted the rapid development of automated protein structure determination using X-ray crystallography. Robotics are now routinely used along the pipeline from genes to protein structures. However, a bottleneck still remains. At synchrotron beamlines, the success rate of automated sample ali…
Abstract The high melt viscosity of polypropylene was studied by grafting bifunctional monomers, 1,6‐hexanediol diacrylate (HDDA) and tripropylene glycol diacrylate (TPGDA), onto homopolypropylene (HPP) and random ter‐polypropylene (RTPP) under electron‐beam irradiation. Creation of the high‐melt‐viscosity polypropyle…
A new type of very compact Pacman bis-porphyrin scaffold has been obtained in which a calix[4]arene spacer provides both cofacial preorganization and flexibility. Changes in the distance between the two tetrapyrrolic macrocycles can be triggered by electrochemistry, where closed and open conformers can be interconvert…
Use of mixtures of blowing agents in thermoplastic foam extrusion has been an industrial practice for a long time. However, it has gained renewed interest in the past few years due to the introduction of difficult-to-process alternative gases, targeted as potential replacement for the banned ozone-depleting blowing ag…