Materials Literature
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Our previous work confirmed the excellent activity of CuO−MoO 3 /Al 2 O 3 for the destructive oxidation of (CH 3 ) 2 S 2 . This study further investigates the effect of acid treatment on the performance of this catalyst. Four different kinds of inorganic acids (HCl, H 2 SO 4, HNO 3, H 3 PO 4 ) are used to treat the γ-…
Self-reinforced polypropylene (PP) sheets have been prepared from melt flow-induced crystallization through a conical slit die fed by a conventional extruder. Their structure and properties, influenced by the die pressure ranging from 20 to 50 MPa and die outlet temperature, are studied by scanning electron microscopy…
The phase morphology and interfacial regions of cured and uncured polybutadiene/diallyl phthalate (PBD/DAP) blends that exhibit upper critical solution temperature (UCST) behavior have been characterized using an FT-IR microscopic imaging technique with focal-plane array detection. The observations of domain size and…
Method for introducing grafted chains consisting of two types of monomer components, acrylic acid (AA) and N-isopropylacrylamide (NIPAAm), into low-density polyethylene (PE) film (thickness = 25 μm) was investigated by two photografting technique using xanthone photoinitiator at 60°C. In the first method (one-step met…
Friction Force Microscopy studies on ion-exchanged mica surfaces at different humidity levels were performed. Ion exchange was achieved by treating the potassium mica (muscovite) in different solutions to replace K + surface ions by Ca 2+, Mg 2+, and H + . It is found that these different surface ions can significantl…
Spectrally resolved thermoluminescence of co-doped Dy:Tm: shows that the maximum peak temperature for the nominal C dosimetry peak differs by C for Dy and Tm emission. This is interpreted as evidence that the rare earth ions form part of a complex defect which variously provides both the charge trapping and, during he…
The excited multiplet states of (tetraphenylporphinato)zinc(II) (ZnTPP) coordinated by p -pyridyl nitronyl nitroxide ( p -nitpy), ZnTPP− p -nitpy, and of ZnTPP coordinated by m -nitpy, ZnTPP− m -nitpy, were studied by time-resolved electron paramagnetic resonance (TREPR). The TREPR spectra observed at 20 K and 0.5 μs…
A blend of chitosan and viscose rayon was investigated. A film was made from regenerating the blend of chitosan and viscose rayon. The film was characterized by various techniques, including Fourier transform infrared spectroscopy (FTIR), wide-angle X-ray scattering (WAXS), differential scanning calorimetry (DSC), dyn…
The melt grafting of glycidyl methacrylate (GMA) onto powdered isotactic polypropylene (PP) in a Haake Rheocord RC90 mixer was studied. Grafting degrees were determined by nonaqueous back titration of trichloroacetic acid with sodium hydroxide. The extent of degradation and crosslinking of PP during grafting was indic…
The structure, surface acidity, and reducibility of WO 3 /SiO 2 systems, obtained by impregnation of the silica support with aqueous paratungstate solutions, are described. The effect of tungsten loading and calcination temperature on the nature and physicochemical properties of tungsten-containing phases has been stu…
The decomposition under thermal treatments of an hydrotalcite sample prepared from Mg and Al chlorides, thus containing Cl - and CO 3 2 - as compensating anions, and of the same sample totally exchanged by CO 3 2 -, was followed by several characterization techniques (in situ XRD, 27 Al NMR, TG, chemical analysis). A…
Dynamical experimental studies on the diffraction efficiencies and the formation of birefringence grating and surface relief grating on doped and/or covalently bonded azobenzene derivatives containing polymer films were carried out using laser beams with different polarizations. From polarization analyses of the first…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSynthesis and Structure of Isolated Silicon Clusters of Nine AtomsVirginie Quéneau, Evgeny Todorov, and Slavi C. SevovView Author Information Department of Chemistry and Biochemistry University of Notre Dame Notre Dame, Indiana 46556 Cite this: J. Am. Chem. Soc. 1998,…
The pressure distribution beneath a conical sandpile, created by pouring sand from a point source onto a rough rigid support, shows a pronounced minimum below the apex (`the dip'). Recent work of the authors has attempted to explain this phenomenon by invoking local rules for stress propagation that depend on the loca…
A molecular mechanism explaining the chemical phenomena that occur during the preparation of silica-supported nickel catalysts by the method of deposition−precipitation is proposed. This mechanism takes into account the fact that either 1:1 nickel phyllosilicate or nickel hydroxide may be formed on silica during depos…
The effect of partial substitution of Fe by Al (Al, Al 2 O 3 ) on the magnetic properties and the corrosion resistance of the sintered NdFeB magnet has been investigated. With the increasing amount of Al, the anisotropy field and the saturation magnetization decrease, but the coercivity increases up to 4 at.% Al and f…
We have previously described an original model called the EVM (energy, volume, and mass) model, which uses only three descriptors, the energy of a polymer segment conformation using molecular mechanics and molecular dynamics, its volume (the occupied space by the atoms as well the unoccupied space between them), and t…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTIsocyanate as a Versatile Synthon for Modular Synthesis of Functionalized PorphyrinsJames P. Collman, Zhong Wang, and Andrei StraumanisView Author Information Department of Chemistry, Stanford University, Stanford, California 94305-5080 Cite this: J. Org. Chem. 1998, 6…
Multinuclear NMR spectroscopy has been used to study water bound to subtilisin Carlsberg suspended in tetrahydrofuran (THF), with the water itself employed as a probe of the hydration layer's physicochemical and dynamic characteristics. The presence of the enzyme did not affect the intensity, chemical shift or linewid…
The synthesis and characterization of two rhodium(I)dicarbonyl amethyrin complexes (mono and bis) are presented. X-ray structural results reveal that the amethyrin ligand undergoes significant distortion from planarity as the result of metal complexation and that, in the case of the bis-rhodium complex, the two metal…