Materials Literature
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Single-walled carbon nanotubes (SWNTs) with the N -alkylidene amino groups covalently attached to their side walls have been prepared starting from colloidal solutions of fluorinated SWNTs (fluoronanotubes) in terminal alkylidene diamines followed by heating at 70−170 °C. On the basis of data from thermal gravimetric…
Abstract Waste poly(ethylene terephthalate) [PET] and a polyolefinic elastomer (POE), Engage™ 8150, were melt blended in a co‐rotating twin screw extruder having initial distributive mixing followed by high shearing/stretching. Compositions having POE up to 10% with and without poly(ethylene‐ co ‐acrylic acid), as a c…
In addition to two organic superconductors (DODHT)2X [DODHT = (1,4-dioxane-2,3-diyldithio)dihydrotetrathiafulvalene; X = PF6 and AsF6] previously reported by us, the BF4 salt of DODHT containing one water molecule [(DODHT)2BF4 x H2O] has been found to undergo a superconducting transition at 3.2 K under a hydrostatic p…
Abstract The sorption of platinum on glutaraldehyde cross‐linked chitosan was investigated at pH 2, using several chitosan samples prepared from different origins and characterized by different mol fractions of N ‐acetylation ( F A ). The influence of material conditioning was also tested: chitosan was dissolved and t…
An unexplored family of polyoxometalates has evolved through the synthesis and structural characterization of vanadium(IV) sulfite heteropolyanions. The hexanuclear vanadium(IV) compound, which is ferromagnetic down to 2 K, exhibits a unique structural motif for such metal species, with a central cubic {M4O2(OH)2} fra…
Abstract The application of Raman microscopy to the study of closely related mineral phases of the adelite group has allowed their molecular characterization. The adelite group of minerals are orthorhombic arsenates and vanadates of general formula AB 2+ (XO 4 )(OH), where X may be As 5+ or V 5+ , cation A may be Ca o…
Strong Heisenberg exchange between the core MnIII ion (S=2) and peripheral CuII ion (S=) creates S= and total-spin manifolds in a ClMnIII-complexed porphyrazine (tetraazaporphyrin) to which a CuII-complexed Schiff base is rigidly linked through nitrogen atoms attached to the macrocycle periphery (1). EPR spectroscopy…
Crystals as building blocks: Self-assembled crystals are obtained through hierarchical and self-similar growth. Using microscopic, polyhedral, self-assembled crystals as building blocks, large crystals and open mesophase structures which preserve the shape and orientation of the basic structural units are spontaneousl…
Abstract A series of new polyimides containing s ‐triazine rings have been synthesized via Diels–Alder intermolecular polymerization of 2,6‐bis(2‐furanylmethylimino)‐4‐isopropoxy‐1,3,5‐triazine with various bis(maleimide)s. All the poly(imino‐ s ‐triazine imide)s were characterized by elemental analyses, FTIR spectral…
Iod als Leim für Nanoaggregate: Mit der spontanen Chemisorption von Iod auf Gold-Nanopartikeln geht eine Elektroneninjektion von Iod auf Gold einher, was zur Fusion der Nanopartikel und schließlich zur Aggregation führt; ein Überschuss an KI führt zur Bildung von Nanokristallen (siehe Schema). Oberflächengebundene und…
Abstract The phonon dispersion curves for α‐SiO 2 crystals were calculated on the basis of a rigid‐ion model. The first‐order Raman spectra of the A 1 mode of the α‐SiO 2 crystal were measured in the temperature range from 303.1 to 773.1 K. The temperature dependence of the linewidth was analyzed by using the phonon d…
Abstract Films of polymer blends having various contents of poly(vinyl alcohol) (PVA) and polyacrylamide (PAM) were prepared by the solution casting technique using water as a common solvent. The thermal, mechanical and morphological properties of these blends before and after exposure to various doses of gamma radiat…
Abstract Butylammonium hexafluorosilicate, (n‐C 4 H 9 NH 3 ) 2 SiF 6 , crystallizes at room temperature in the trigonal system with a probable space group P 321. A new structural phase transition was detected at low temperatures for this compound by means of differential scanning calorimetry (DSC) and the basic thermo…
Received 14 January 2003DOI:https://doi.org/10.1103/PhysRevB.67.039902©2003 American Physical Society
N-type ZnO thin films were successfully grown by sol-gel dipping coat method on glass substrates at 300–600 °C under air atmosphere. Poly ZnO thin films were obtained at more than 300 °C. Values of full width at half maximum of (0002) peak at the XRD spectra became small with the increasing the substrate temperatures.…
Abstract Information about confinement effects and dot–matrix interactions of CdS nanoparticles was obtained from resonance Raman spectroscopy. The quantum dots had diameters of 3 and 5 nm and were prepared with and without organic spacer groups. It was found that the spacer improves the quality of the nanocrystallite…
We report resonant inelastic x-ray scattering experiments of the orbitally ordered manganite ${\mathrm{LaMnO}}_{3}.$ When incident photon energy is tuned near the Mn K absorption edge, the spectra reveal three features at 2.5, 8, and 11 eV. The 8- and 11-eV peaks are ascribed to transitions from the O $2p$ bands to th…
Calcination of a layered double hydroxide precursor containing MgII, FeII and FeIII cations with an Mg2+:(FeII + FeIII) ratio of 0.5 affords a pure ferrite spinel, MgFe2O4, which has a higher saturation magnetization than samples of the same material produced by conventional ceramic routes.
Monolayer protected gold nanoparticles synthesised by a two-phase method contain a significant amount of tetraoctylammonium bromide (TOABr), the quaternary ammonium salt used as the phase transfer reagent, as a persistently retained impurity. A simple purification protocol is described.
An original nanocone with 240° disclination arises naturally from a planar hexagonal sheet when four 60° segments originating from adjacent hexagonal centers are cut out of the plane and the severed edges of the segments are rejoined. The comparison among the calculated total energies of several pure carbon nanocones…