Materials Literature
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We show that the optical absorption spectra of boron nitride (BN) nanotubes are dominated by strongly bound excitons. Our first-principles calculations indicate that the binding energy for the first and dominant excitonic peak depends sensitively on the dimensionality of the system, varying from 0.7 eV in bulk hexagon…
Holey zeolites! Hierarchical mesoporous zeolites (see SEM image) were prepared by a one-step hydrothermal reaction using both a small organic ammonium salt and a mesoscale cationic polymer as templates. The zeolites thus obtained reveal excellent catalytic properties relative to conventional zeolites, indicating the i…
Löchrige Zeolithe! Hierarchische mesoporöse Zeolithe (siehe SEM-Bild) wurden in einer einstufigen Hydrothermalreaktion unter Verwendung eines kleinen organischen Ammoniumsalzes und eines mesoskaligen kationischen Polymers als Template synthetisiert. Die erhaltenen Zeolithe sind sehr viel bessere Katalysatoren als gäng…
A general method based on two-phase polymerization has been described to synthesize mesoporous carbons via self-assembly. Mild reacting conditions and wide composition ranges are the obvious advantages of this method over the techniques previously reported.
Abstract The micromechanical properties of injection‐molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X‐ray diffraction methods. The microhardness of the composites was show…
When Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) with 40 wt% excess PbO is sintered at 1050°C, the grains grow normally and have flat {100} surface segments with round edges. As PbTiO 3 (PT) is added up to 8 mol%, the grain growth is still nearly normal, characterized by time invariant normalized size distributions, but the grain edg…
Abstract In this work, X‐ray photoelectron spectroscopy (XPS) analyses were performed in order to identify the surface composition of oxide films electrochemically grown on Ti–50Zr and to verify whether anions from the electrolytes (H 3 PO 4 , H 2 SO 4 , and CH 3 SO 3 H) were incorporated into these oxide films. For a…
Abstract Thin sol–gel V 2 O 5 films were examined before and after lithium electrochemical intercalation/de‐intercalation cycles. X‐ray photoelectron spectroscopy (XPS) was used for surface characterisation, while microstructure and morphological characteristics were studied by atomic force and electron microscopies (…
Abstract Lamellar double hydroxides with different proportions of Ni, Cu, Mg and Al were prepared and calcined at 723 K to obtain mixed oxides with acid–base and redox properties. The acidic and basic sites of the surface of these catalysts were characterized by adsorption microcalorimetry, XPS coupled with adsorption…
Abstract The molecular characteristics of the room‐temperature soluble fractions (RT solubles) of three low‐density polyethylene film resins were characterized by size‐exclusion chromatography (SEC), SEC combined with FTIR (SEC–FTIR), and nuclear magnetic resonance spectroscopy (NMR). The high‐molecular‐weight compone…
The NMR and EPR spectra of two bisimidazole and three bispyridine complexes of tetraphenylchlorinatoiron(III), [(TPC)Fe(L)2]+ (L = Im-d4, 2-MeHIm, 4-Me2NPy, Py, and 4-CNPy), have been investigated. The full resonance assignments of the [(TPC)Fe(L)2]+ complexes of this study have been made from correlation spectroscopy…
Abstract Steady‐state and oscillatory shear behavior of three neat syndiotactic polypropylene (s‐PP) resins and a s‐PP resin (s‐PP#8) filled with CaCO 3 particles of varying content, size, and type of surface modification were investigated. All of the neat s‐PP resins investigated exhibited the expected shear‐thinning…
Abstract A brief overview is given on several aspects of applications of the Monte Carlo (MC) simulation method to surface‐related electron spectroscopy and microscopy. For the MC modeling of electron interaction with solids, the electron inelastic scattering cross section is calculated by the use of bulk dielectric f…
The temperature dependence of the density correlation function at next neighbor distances has been investigated for the liquid metal rubidium. This correlation function is a sensitive parameter for changes in the local structure and its Fourier transform was measured in a coherent inelastic neutron scattering experime…
Abstract This work experimentally monitored the physical and mechanical properties of natural rubber/carbon black/reclaimed rubber blends vulcanized by microwave (MW) irradiation and conventional thermal (CT) systems, and the curing mechanisms are addressed in conjunction with the vulcanizate properties. The microwave…
Abstract The homogeneous catalyst precursor, OsHCl(CO)(O 2 )(PCy 3 ) 2 , was utilized for the hydrogenation of natural rubber to convert the unsaturated structure to a saturated form, providing an alternating ethylene‐propylene copolymer. A detailed kinetic investigation was carried out by monitoring the amount of hyd…
Ultrathin films of ZnS were grown on Au (111) substrates using a novel, simple co-deposition method and characterized using X-ray diffraction (XRD), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and UV-visible spectroscopy. Cyclic voltammograms were used to determine approximate deposition pot…
Abstract The energy distribution of electrons backscattered elastically from polyethylene is studied. The separation between the carbon and hydrogen peak in the energy distribution is shown. Furthermore, the effect of the multiple scattering on the energy shifts and Doppler broadenings is determined using Monte Carlo…
Abstract A suspension of carbon nanotubes in natural latex was obtained by liquid mixing and then was used to prepare powder natural rubber composites modified with carbon nanotubes by means of spray drying process. The composite powders were round‐like and fine, with an average diameter of less than about 5 μm. The d…
Abstract The angular distributions of electrons backscattered elastically from a polycrystalline silver sample are studied theoretically. The simulation is based on the Monte Carlo technique where both the elastic and inelastic scattering events are taken into account. We analyzed the effect of multiple electron scatt…