Materials Literature
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The chemistry of thorium phosphate reported in the literature has been found to be erroneous. It was reconsidered in terms of careful chemical preparations and specific analytical methods. Special attention has been paid to the atom ratio value referred to r = thorium/phosphorus, which was experimentally fixed in orde…
For the first time, an aqueous micellar medium (sodium dodecyl sulfate, SDS) is used, at Pt electrodes, to electrosynthesize poly(3,4-ethylenedioxythiophene)(PEDOT) conducting films deposited at lower potential than in acetonitrile and presenting a well organized structure.
The synthesis and characterization (by optical microscopy, differential scanning calorimetry (DSC), X-ray diffraction) of two series of octasubstituted lipophilic phthalocyanines 1 − 3 and 4 − 7, bearing amide functions in the peripheral chains, are reported. Compounds 1 − 3, 6, and 7 exhibit a liquid-crystal phase, f…
Ring-opened homopolymers of 5-norbornene-2-carboxylates or 5-norbornene-2,3-dicarboxylates that contain acetal-protected sugars ( 1: 1,2:3,4-di- O -isopropylidene-α- d -galactopyranos-6- O -yl 5-norbornene-2-carboxylate; 2: bis(1,2:3,4-di- O -isopropylidene-α- d -galactopyranos-6- O -yl) 5-norbornene- trans -2,3-dicar…
X-ray diffraction (XRD) and transmission electron microscopy (TEM) have been used to characterize microstructural and microchemical changes produced by neutron irradiation in zirconium and zirconium alloys. Zircaloy-2, Zircaloy-4, and Zr-2.5Nb alloys with differing metallurgical states have been analyzed after irradia…
Many biologically formed calcite crystals contain intracrystalline macromolecules. The ways in which they interact with growing calcite crystals were evaluated by monitoring changes in the morphology of calcite crystals grown in vitro in their presence. Macromolecules were extracted from within isolated prisms from th…
Collagens can be distinguished from other proteins based on their triple-helical structure. Synthetic peptide models have been developed to better understand the triple helix structurally and to evaluate the triple helix as a recognition element for biological processes. Associated triple-helical peptides were first d…
Several solution properties of complexes formed between the trivalent lanthanide ions (Ln III ) and the macrocyclic ligand DOTP 8 -, including stability constants, protonation equilibria, and interactions of the LnDOTP 5 - complexes with alkali metal ions, have been examined by spectrophotometry, potentiometry, osmome…
Isotherms have been determined for the adsorption of polyvinylpyrrolidone (PVP) samples of various molecular mass (10 4 to 2.5 × 10 6 ) onto anionic polystyrene (PS) latices from both water and 0.5 M NaCl. The adsorption capacity, Γ ads, was found to be about 0.7 mg m -2 from water and was independent of the PVP molec…
The synthesis and characterization of novel non-centrosymmetrically push-pull substituted metal-free phthalocyanines 3 − 9 are described. The compounds have different donor (dialkoxy, tert -butyl, methyl, p -tolylthio) and/or attractor ( p -tolylsulfinyl, p -tolylsulfonyl, nitro) functional groups, are soluble in orga…
ε-Caprolactone polymerization using an initiating system comprising tris(2,6-di- tert -butylphenoxy)yttrium and 2-propanol was first-order in monomer and initiator. A propagation rate constant of 1.65 L·mol -1 ·s -1 was determined in dichloromethane. The reaction proceeds via a three-step mechanism. In the first step…
The effect of crystallinity on the photoreduction of cerium oxide (Ce 4+ to Ce 3+ ) during X-ray photoelectron spectroscopy (XPS) analysis of CeO 2 and Ce/Al 2 O 3 catalysts has been determined. Cerium oxide samples were prepared by calcining cerium(IV) methoxyethoxide in air at different temperatures. The structure o…
FT-IR spectroscopy, synchrotron SAXS, and dynamic rheometry have been employed to monitor, in-situ, structure development during the reactive processing of model flexible polyurethane foam systems. The following combinations of components were investigated: (I) diisocyanate, polyether polyol, and water and (II) diisoc…
The coordination chemistry of 2,2'-dipyridyl diselenide (PySeSePy) (2) (C(10)H(8)N(2)Se(2)) has been investigated and its crystal structure has been determined (monoclinic, P2(1)/c, a = 10.129(2) Å, b = 5.7332(12) Å, c = 19.173(3) Å, beta = 101.493(8) degrees, Z = 4). In metal complexes the ligand was found to coordin…
Unsymmetrical phthalocyanine analogues with three 15-crown-5 ether voids at the 3,4-positions (MtNIL, MtBZ, MtNAP) (Mt = Zn, Cu) have been synthesized and characterized. Their dimerization is induced by addition of some cations, particularly Rb 2+ and K + . Cofacial dimer formation in the presence of these cations pro…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSelf-Ordering of Diblock Copolymers from SolutionZ. Li, W. Zhao, Y. Liu, M. H. Rafailovich, J. Sokolov, K. Khougaz, A. Eisenberg, R. B. Lennox, and G. KrauschView Author Information Department of Materials Science and Engineering State University of New York at Stony B…
The electrochemical and chemical oxidation of the defect perovskite SrCoO 2.5 to the cubic perovskite SrCoO 3 at ambient temperature in alkaline electrolyte are shown to be reversible processes with the appearance of intermediate compounds; the phase diagram can be described by two line phases SrCoO 2.5 and SrCoO 2.75…
The aim of this study was to gain information on the influence of the core moiety on the kinetics of the synthesis of hyperbranched polyesters based on 2,2-bis(methylol)propionic acid (bis-MPA). Bis-MPA was esterified in the melt using sulfuric acid as a catalyst, yielding a highly polydisperse polyester. Bis-MPA was…
Electrically switchable volume holograms lead to the possiblity of real-time electro-optical control of diffractive optic components. We report here on the development of a novel photopolymer-liquid crystal composite material system for writing in a fast single step, high diffraction efficiency volume holograms, capab…
A short review of beneficial effects of nitrogen in steel is given including mechanical and corrosion properties, and the data of interatomic interactions and distribution of solute atoms in solid solutions are discussed with the aim of explanation of the physical nature of nitrogen steels. The concept is presented ac…