Materials Literature
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Electrical current can be completely spin polarized in a class of materials known as half-metals, as a result of the coexistence of metallic nature for electrons with one spin orientation and insulating for electrons with the other. Such asymmetric electronic states for the different spins have been predicted for some…
The electronic conductance of a molecule making contact to electrodes is determined by the coupling of discrete molecular states to the continuum electrode density of states. Interactions between bound states and continua can be modeled exactly by using the (energy-dependent) self-energy, or approximately by using a c…
The recent interest in the imaging possibilities of photonic crystals (superlensing, superprism, optical mirages etc...) call for a detailed analysis of beam propagation inside a finite periodic structure. In this paper, we give such a theoretical and numerical analysis of beam propagation in 1D and 2D photonic crysta…
The energetics of pure-phase rutile nanorods and spherical anatase nanoparticles have been studied by high-temperature drop solution calorimetry in 3Na 2 O·4MoO 3 solvent at 975 K and water adsorption calorimetry in a wide range of particle sizes (surface area) from 6 to 40 nm (5−270 m 2 /g). The calorimetric surface…
Nanorods composed of 9-tert-butylanthroate (9-TBAE) are synthesized using an Al2O3 template and solvent annealing. The rods consist of micron-scale crystalline domains, and UV light induces a [4 + 4] photodimerization that results in a uniform 15% expansion along the rod axis. This is in contrast to random 9-TBAE crys…
We present a combined density functional theory (DFT)/time-dependent density functional theory (TDDFT) study of the geometry, electronic structure, and absorption and emission properties of the tetranuclear "cubane" Cu4I4py4 (py = pyridine) system. The geometry of the singlet ground state and of the two lowest triplet…
Aligned ultralong ZnO nanobelts with an average length of 3.3 mm and widths up to 6 μm (see figure) are synthesized on a metal substrate through a one-step process. The nanobelts obtained from this molten-salt-assisted thermal evaporation route show an emission current density of 1 mA cm–2 at an electric field of 2.9…
We demonstrate that any metal, even gold, silver, and copper, can act as a catalyst for SWCNT synthesis in chemical vapor deposition (CVD). Metal nanoparticles 3 nm or less in diameter, introduced into CVD ambience immediately after heat treatment at 800-950 degrees C in air, produce SWCNTs. The activation method is e…
The applicability of the proton conductor Ba(Zr0.1Ce0.7Y0.2)O3–δ (BZCY7) as an electrolyte material for solid-oxide fuel cells (SOFCs) is investigated. The electrolyte material exhibits ionic conductivities (see figure) among the highest known for electrolytes viable for SOFC applications, and the chemical and thermal…
Abstract Polyaniline was synthesized in the presence of tanninsulfonic acid to yield a product tanninsulfonic acid‐doped polyaniline (TANI‐PANI) that is water‐dispersible. Several samples ranging from 0 to 70% tanninsulfonate (TS) were prepared. These samples were then evaluated for differences in dispersibility, part…
The crystal structure of the title compound, copper(II) diselenium(IV) pentoxide [Meunier, Svensson & Carpy, (1976). Acta Cryst. B32, 2664–2667], has been reinvestigated and confirmed to much higher precision, and anisotropic displacement parameters has been refined. The structure consists of CuO4 planar squares and S…
The synthesis of dendritic polymers, i.e., dendrimers (ideally branched) and hyperbranched polymers (non-ideally \nbranched) and investigation of their properties have gained large scientific attention over the last twenty years [1]. \nDendrimers are difficult and expensive to synthesize, while hyperbranched (…
The crystallographic structure of ${\mathrm{U}}_{4}{\mathrm{O}}_{9\ensuremath{-}y}$ crystals can be described in terms of a spatial arrangement of special aggregates of oxygen atoms distributed throughout the basic fluorite framework of ${\mathrm{UO}}_{2}$. The structure of ${\mathrm{U}}_{4}{\mathrm{O}}_{9\ensuremath{…
Abstract A novel superabsorbent composite, polyacrylamide/attapulgite, from acrylamide (AM) and attapulgite (APT), was prepared by free‐radical polymerization, using N,N′ ‐methylenebisacrylamide (MBA) as a crosslinker and ammonium persulfate (APS) as an initiator. The effects of hydrochloric acid (HCl) concentration,…
Abstract The major objective in this study was the preparation of polyacrylonitrile (PAN) nanofibers composed of 1,4‐bis( o ‐cyanostyryl)benzene (ER) and 1‐( o ‐cyanostyryl)‐4‐( p ‐cyanostyryl)benzene (EB), two kinds of fluorescent whitening agents widely used in the textile industry. The scanning electron microscopy…
Mesostructured carbon materials were obtained by nanocasting MCM-48 and SBA-15 ordered mesoporous silica templates via two carbon infiltration routes: a liquid-phase process (LPI) using sucrose solution or a gas-phase chemical vapor infiltration (CVI) process using propene. The structural characteristics of the carbon…
Dielectric measurements under steady shear flow are made to clarify the shear induced structural changes in the nematic (N) and the smectic-A (SA) phases of 4-n-octyl-4'-cyanobiphenyl (8CB). In the N phase, the temperature dependence of the dielectric permittivity shows a characteristic behavior, which can be consiste…
Abstract The purpose of this work was to study how mineral fillers would behave in a polypropylene (PP) matrix when PP modified with maleic anhydride (MA) and/or itaconic acid (IA) was used as a coupling agent in the preparation of mineral‐filled PP composites. The composites were characterized with tensile mechanical…
We report on theoretical results concerning the relation between the liquid-liquid transition and the density anomaly for a family of ramp potentials (hard-core plus linear short range repulsion and linear long range attraction). Using first order perturbation, we have studied the influence of the range of the attract…
New picket porphyrins delivering at least one carboxylic group around the coordination site of the macrocycle were synthesized for bismuth coordination. The influence of the number, the length, and the pre-organization of the carboxylic acid pickets on the stability of the bismuth complexes was explored. Their stabili…