Materials Literature
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NiO−MgO samples (Ni x Mg 1- x O: x = moles of Ni/(moles of Ni + moles of Mg)) were prepared by impregnation of MgO powder with an aqueous solution of Ni(NO 3 ) 2, followed by calcination at 773 K. The dispersion of Ni ions in these samples has been studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (…
Chemical activation and process intensification is provided through ultrasonically-induced cavitation in a liquid medium, a process often described as sonochemistry. Examples are chosen from a number of fields which illustrate the wide ranging applicability of this technology in the chemical and processing industries.…
An improved synthesis of the prototype polyoxoanion−organometallic-support system, P 2 W 15 Nb 3 O 62 9 -, as its organic solvent-soluble all-[( n -C 4 H 9 ) 4 N] + salt is described. The improvements result in a 30% faster procedure which also provides a 60% increase in yield of [( n -C 4 H 9 ) 4 N] 9 P 2 W 15 Nb 3 O…
Spectroelectrochemical behaviour of regioregular poly(3-octylthiophene) has been investigated using UV–VIS–NIR and Raman spectroscopies. Static and dynamic UV–VIS–NIR spectroelectrochemical experiments combined with cyclic voltammetry show that oxidative doping of the regioregular polymer is a two-step process in whic…
Two new thermally irreversible photochromic ( R )-binaphthol-condensed indolylfulgides (with a 1-(1,2-dimethyl-3-indolyl)-2-methylpropylidene group and with a 1-(1,2-dimethyl-3-indolyl)butylidene group, 6 and 7, respectively) were synthesized. Because of rapid thermal equilibration between the conformational isomers o…
Mercury ions, Hg 2+, are radiolytically reduced in an aqueous silver sol. The plasmon absorption band of silver is blue-shifted, which is explained by the formation of a solid mercury layer around the silver particles. The metal deposition stops when the silver particles carry about two monolayers of mercury and the a…
We report stochastic calculations in compact 2-D lattices modeling the competition between electron−hole recombination and reactive processes on the surface of illuminated TiO 2 colloidal particles. Computer simulations in which holes perform unbiased random walks, react with oxidizable donors, or neutralize stationar…
Tetraethylsulfamide (TESA), (CH 3 CH 2 ) 2 NSO 2 N(CH 2 CH 3 ) 2, is a nonvolatile liquid of moderate permittivity (ε = 29) that exhibits a good stability toward reducing agents. This glass-forming liquid ( T g = −111 °C) is compared to propylene carbonate (PC, ε = 65, T g = −110 °C) as diluent for PEO−LiN(CF 3 SO 2 )…
A negative working photosensitive polyimide based on poly(hydroxyimide) (PHI), 2,6-bis(hydroxymethyl)-4-methylphenol (BHMP) as cross-linker, and photoacid generator diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS) has been developed. The PHI was prepared by the ring-opening polyaddition of 4,4‘-hexafluoroi…
The crystal structure of the stable crystalline form of syndiotactic polypropylene (s-PP) may be taken, only as a first approximation, as body-centered orthorhombic and described in the space group Ibca (in which the chains maintain their full, ideal 2 1 22 symmetry). Indeed, the splitting of the resonance of the meth…
Pyrroles fused with aromatic rings (isoindole derivatives) have been readily prepared by the reaction of aromatic nitro compounds with ethyl isocyanoacetate in the presence of DBU. The ease of this reaction depends on the aromaticity of the starting nitro aromatics. Polycyclic aromatic nitro compounds such as 1-nitroa…
Blends composed of poly(vinylphenol) (PVPh) and bacterial (tactic) poly(hydroxybutyrate) (PHB) and synthetic (atactic) poly(hydroxybutyrate) (PHBa) have been investigated by FTIR. From quantitative analyses of hydrogen bonded PHB carbonyl groups as a function of temperature and composition, the interassociation consta…
Low-temperature (400−800 °C) stabilization of tetragonal zirconia, prepared by a hydroxide gel route and low-temperature annealing, has been achieved by partial substitution of Zr 4+ with Bi 3+ . XRD and Raman spectroscopy have been used for characterization of the doped zirconia powders as well as for identification…
The surface forces apparatus technique was used to measure the normal forces, thin film viscosity, and lateral (frictional) forces between two surfaces interacting across 4‘- n -octyl-4-cyanobiphenyl (8CB), to determine the effects of confinement (film thickness) and shear (sliding velocity) on the ordering of the sme…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSingle-Crystal X-ray Structure of the Cation Radical of 3',4'-Dibutyl-2,5''-diphenyl-2,2':5',2''-terthiophene: Definitive Evidence for π-Stacked Oxidized OligothiophenesDavid D. Graf, John P. Campbell, Larry L. Miller, and Kent R. MannView Author Information Department…
The deformed structure of cold rolled IF steels consists of a large number of α fibre and γ fibre oriented grains and a small number of (110)<110> oriented grains, each with a distinctive grain shape, subgrain structure, hardness and etching appearance. Early nucleation occurs mainly in γ fibre grains and (110)<110> g…
Layered double hydroxides containing silicate anions have been prepared using either a coprecipitation method or an anionic exchange reaction. The polymerization of the intercalated anions under moderate thermal treatment has been studied by PXRD, FTIR, and solid-state NMR. Grafting processes and layer condensation ha…
Deterioration of stator winding insulation continues to be one of the predominant causes of large motor and generator failures. Over the past several years, practical methods have been developed for measuring the partial discharge activity in the high voltage insulation of stator windings, since partial discharges are…
The super-H-shaped block copolymers belong to a new class of polymeric materials, the miktoarm stars (mikto from the Greek word μικτο ς meaning mixed), which includes star-shaped polymers in which from one or more junction points radiate different arms. Schematically, the super-H structure can be described as two thre…
1 H nuclear magnetic resonance (NMR) relaxation studies of the temperature-induced micellization of a poly(ethylene oxide)−poly(propylene oxide)−poly(ethylene oxide), PEO−PPO−PEO, block copolymer in aqueous solution were performed in the range 280−345 K. 1 H NMR spectra of the block copolymer were well resolved, thus…