Materials Literature
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Aluminosilicates were prepared by the sol−gel method using tetraethoxysilane as silica source and aluminum ethoxide, aluminum iso-propoxide, or aluminum sec -butoxide as alumina sources. An important effect of the alkylaluminum substitutes is observed in the BET specific area, ethoxide > isopropoxide > sec -butoxide.…
Curing bis(maleimide) (BMI) with diallylbisphenol A (DABPA) results in the formation of a high-performance thermoset resin. A variety of reactions in which maleimide units are converted to succinimide moieties have been proposed. In order to make spectral assignments for the fluorescence behavior observed during the c…
The fracture toughness G c of an interface between the immiscible homopolymers polystyrene (PS) and poly(2-vinylpyridine) (PVP) reinforced with random copolymers, dPS f − r -PVP 1- f was measured as a function of the average monomer fraction f and the areal chain density Σ of the copolymer. Long symmetric random copol…
The compound [Cu(cyclam)(TCNQ) 2 ](TCNQ) (cyclam = 1,4,8,11-tetraazacyclotetradecane, TCNQ = 7,7,8,8-tetracyanoquinodimethane) has been obtained in two different crystallographic forms, isomers 1 and 2 . Crystal data for isomer 1: triclinic, P 1̄, a = 7.855(6) Å, b = 10.267(2) Å, c = 14.424(3) Å, α = 95.42(2)°, β = 10…
The bonding of atomic oxygen on Pt(111) and Rh(111) was examined using density functional theory in order to understand their different chemical properties. The oxygen−surface interactions were modeled by bonding atomic oxygen to 10-atom clusters of Pt and Rh designed to model the (111) surface. Density functional the…
A series of alkyl and dialkylammonium polyacrylates were synthesized by neutralizing a 5000 molecular weight poly(acrylic acid) with alkyl- and dialkylamines. Their thermal stability was investigated using thermogravimetry. Their thermotropic liquid crystal behavior was analyzed using differential scanning calorimetry…
Reactions of nitridomanganese(V) porphyrins with chromium(III) porphyrins resulted in the irreversible formation of nitridochromium(V) porphyrins and manganese(III) porphyrins. The progress of these reactions has been followed spectrophotometrically, electrochemically, and spectroscopically by EPR. Kinetic analysis of…
Near-threshold photoelectron recapture due to postcollision interaction with a single Auger electron is examined within the quantum-mechanical framework of radiationless resonant Raman scattering. Model calculations using a hydrogenic approximation are performed, revealing general features of the escape probability as…
Water vapor adsorption and liquid penetration into thermally oxidized porous silicon films were studied by variable angle spectroscopic ellipsometry. Characterization of the surfaces in air combined with multilayer optical modeling showed the existence of a gradient in the volume porosity and bulk‐like silicon skeleto…
The crystal structures of potassium tetratellurite and potassium ditellurite are reported, completing the series of known phases of alkali tellurites including lithium, sodium, potassium and cesium. Potassium tetratellurite (K 2 Te 4 O 9, a = 7.572(1) Å, b = 17.821(3) Å, c = 7.829(1) Å, β = 108.62°, monoclinic, P 2 1…
Abstract The constant rate stretching of amorphous poly(ethylene terephthalate) films is the first step of the industrial “inverse” process. To study this process, films deformed under uniaxial planar symmetry conditions have been produced on a laboratory stretching machine in order to discuss the influence of macrosc…
Abstract A new family of cone‐shaped podands and barrel‐shaped cryptands based on calix[4]arenes incorporating 5,5′‐substituted 2,2′‐bipyridine subunits were prepared and characterized. The Eu 3+ and Tb 3+ complexes of the podands bearing two, three, or four bipyridine chromophores could be isolated. High molar absorp…
The Fourier transform infrared (FTIR) spectra and Raman spectra of fluorine-doped silicon oxide films capped by silicon nitride thin film to prevent water absorption from the air were measured as a function of the fluorine concentration in the films. It was found that fluorine doping diminishes the Si–OH bonds in film…
During the study of the electrostatic spray deposition technique, porous LiCoO 2 thin layers with reticular structures were formed. This discovery has been successfully extended to many other important ceramic materials used in electrochemical devices such as LiMn 2 O 4 , LiNiO 2 , LiCoO 2 , Li 3 PO 4 , Li 0.1 BPO 4 ,…
A simple method for preparing thin dichroic metal composite films is described. Alkanethiol-derivatized gold particles are incorporated into poly(tetrafluoroethylene) (PTFE) matrixes that have been friction-transferred onto glass slides. Exposure of these gold particle/PTFE composites to flame (ca. 1700 °C) leads to s…
A series of linear copolymers of DTPA-class Gd3+ conjugates, linked by alpha, omega-alkyldiamides with a varying number (n) of methylenes separating the amide function, were synthesized. Surprisingly, their relaxivities at all fields increased with increasing n. At MRI fields and 35 degrees C, the relaxivities of the…
Phase diagrams for aliphatic alcohols + magnesium sulfate + water were measured. The alcohols used were ethanol, 1-propanol, 2-propanol, and 2-methyl-2-propanol. Phase diagram data were obtained at 25 °C, and for magnesium sulfate + ethanol + water at 25 °C and 35 °C.
The allowable range of marginal variation of the cell gap to ensure uniform optical properties when using in-plane switching (IPS) of liquid crystals was evaluated quantitatively. The analysis yielded relationships of transmittance into the cell gap in bright, selected bright and selected intermediate states. The sele…
The biodegration behavior of polycaprolactone–poly(ethylene glycol) block copolymer (PCL–b–PEG) was identified by degradation tests in vitro and in vivo. The tests in vitro and in vivo were carried out by immersing samples in pH 5.0, 7.2 and 9.0 buffer solutions with or without lipase at 25.0, 37.0 and 50.0±°C, and im…
The collapse and recrystallization of zinc-exchanged sodium zeolite-A has been observed in situ using combined X-ray spectroscopy and diffraction. The temperature at which this occurs is reduced by the presence of zinc, but the precipitation of NaAlSiO 4 (nepheline) is blocked by the nucleation of ZnAl 2 O 4 (gahnite)…