Materials Literature
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In search of highly active nanoparticles for catalytic applications, flame aerosol technology turns out to be a promising method for its capacity to consistently produce highly pure nanoparticles. Starting with the production of simple oxides such as silica and titania in the forties, flame aerosol technology now faci…
Abstract The equilibrium and kinetics of proteins sorption and desorption by oppositely charged lightly crosslinked polyelectrolytes (#PE) were studied. The driving force of the sorption is provided by interpolyelectrolyte addition reaction (IPAR) between oppositely charged ionic groups of protein and #PE resulting in…
This work investigates the structure and stability of the pyrochlore solid solution Pb n Nb 2 O 5+ n using a combination of high‐resolution electron microscopy and electron diffraction. The microwave dielectric properties of the series 1.5 ≤ n ≤3.0 have been established, and the effect of the substitution of Ta 5+ for…
Abstract Two independent methods of crystal-size distribution analysis were compared: the Bertaut-Warren-Averbach XRD technique (MudMaster computer program) and high-resolution transmission electron microscopy (HRTEM). These techniques were used to measure thickness distributions of illite crystals (fundamental partic…
Abstract Light scattering has proved itself an efficient technique to determine particle diameters in heterogeneous dilute dispersions in the micrometer range. Extrusion of polymer blends is expected to give rise to very small particles, typically in the range from hundreds of nanometers to tens of micrometers. A ligh…
This paper presents an alternative approach aimed toward improvement of protective characteristics of gas-filled surge arresters (GFSA). Although so far GFSA with built-in radioactive sources proved to have superior protective characteristics, environmental concerns often challenge functional benefits. Experimental re…
Abstract Femtosecond fluorescence dynamics of trans ‐azobenzene in hexane have been investigated on excitation to the S 1 (n, π*) state at 432 nm using the up‐conversion technique. Two transient components were observed to represent the fast and the slow S 1 fluorescence dynamics in the wavelength range of 550–732 nm.…
The mesophase exhibited by four members of a new homologous series of compounds composed of banana-shaped molecules derived from 2-cyanoresorcinol is reported. The characteristic optical textures showing helical filamentary growth patterns, coupled with the results from X-ray diffraction studies of these seven-ring co…
We have used a sol−gel technique to obtain optically transparent hydrogels in which water is trapped within a tridimensional disordered silica matrix. A suitable aging of these hydrogels enables to have transparent noncracking samples down to cryogenic temperatures. We report the optical absorption spectra, in the nea…
Abstract Commercial products such as photographic materials and speciality papers manufactured by single or multilayer coating processes, all have some surface topographic structure. Nevertheless, for many materials, a uniform plane approximates their surface, and analyses of dynamic wetting, a fundamental physical pr…
Abstract Single‐wall nanotubes (SWNTs) embedded in polymer can be used as mechanical sensors because the position of the D* Raman band of SWNTs is strongly dependent on the strain transferred from the matrix to the nanotubes. In order to detect the stress (or strain) information in specific directions, polarized Raman…
We numerically analyze the origin of the transmission losses in left-handed structures. Our data confirms that left-handed structures can have very good transmission properties, in spite of the expectable dispersion of their effective permeability and refraction index. The large permittivity of the metallic components…
Commercially available α‐alumina powder with high‐purity, submicrometer particle size and narrow particle‐size distribution is used as starting material to prepare dense ceramic parts with transparent properties. The powder is dispersed and stabilized in a water‐based suspension. Controlled consolidation and drying by…
Abstract In this study, novel biodegradable polymers were synthesized by ring opening polymerization (ROP) of L ‐lactide on chitin in an N,N ‐dimethyl acetamide (DMAc)/lithium chloride (LiCl) solvent system, and chitin was used as macroinitiator to afford new materials. Lithium chloride (LiCl) was used as catalyst. Th…
We compare the vibrational properties of model SiO 2 glasses generated by molecular-dynamics simulations using the effective force field of van Beest et al. (BKS) with those obtained when the BKS structure is relaxed using an ab initio calculation in the framework of the density functional theory. We find that this re…
Cavity ring-down spectroscopy has been used to measure the absorbances, concentrations and temperatures of C2(a3Πu v=0) and CH(X2Π v=0) radicals in a ⩽10 kW dc arc jet used for chemical vapor deposition (CVD) of polycrystalline diamond films and operated with CH4/H2/Ar gas mixtures. Gas temperatures derived from the i…
The methodology developed for evaluating, by total reflection X-ray fluorescence, the main elements in used three-way catalysts for cars after more than 59 000 km is described. The analytical method does not require chemical manipulation of the samples, is quick (30 min for sample preparation and 10 min for analysis),…
A novel precursor, hexakis[μ-(diethylcarbamato-O:O‘)]-μ 4 -oxotetrazinc, (Zn 4 O(CO 2 NEt 2 ) 6 ) ( 1 ), for the single source chemical vapor deposition (SSCVD) growth of ZnO films has been developed. The structure and chemistry of resultant films were characterized using photoemission spectroscopy and diffraction tec…
[formula: see text] A simple straightforward synthesis for meso-monosubstituted, beta-unsubstituted porphyrins is reported. Porphyrins of this type are easily prepared by condensation of dipyrromethane, pyrrole-2-carbaldehyde, and the desired aromatic or aliphatic aldehyde. The method can be used for a variety of func…
Abstract The adsorption of metals by clay minerals is a complex process involving different mechanisms, and is controlled by different variables which can interact. The aim of this work was to study the retention mechanisms of Cd on illite. We obtained Cd adsorption isotherms at constant pH, adsorption edges as a func…