Materials Literature
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The synthesis of low-molecular-weight (Mw (GPC) < 72000 g mol) lactic-acid-based telechelic prepolymers by condensation polymerization of L-lactic acid was investigated. All polymerizations were carried out in the melt, using tin(II)octoate as catalyst, different diols, and different polymerization temperatures. The p…
:Tb thin films have been successfully produced from dichloride ethoxide of zirconium, OEt EtOH and by the sol - gel process. These films show luminescent properties when they are excited with UV light (270 nm). The luminescence spectra present typical transitions from the level belonging to the trivalent terbium ion.…
Nanocrystalline MgO has been sol−gel manufactured to give a range of crystallite sizes from 1.8 to 35 nm as determined by powder X-ray diffraction. A multinuclear magnetic resonance approach using 13 C, 17 O, and 25 Mg provides information on the atomic scale structure. It is found that despite extensive hydrolysis th…
The flammability properties of an intumescent fire retardant polypropylene added with magnesium hydroxide was discussed in this study. To evaluate the flammability of the material, limit oxygen index, smoke emission, tensile strength, and our exploitation dynamic flammability evaluation system, tests were assessed in…
Jute, unlike other natural fibers, absorbs moisture and its moisture regain property is quite high. Water migration and subsequent degradation of jute-based composites can be a problem. Because jute is hydrophilic and the matrix resins are mostly hydrophobic, wetting of the fibers with resins is poor, for which high r…
Siliceous MCM-41 samples were modified by silylation using trimethylchlorosilane (TMCS). The surface coverage of functional groups was studied systematically in this work. The role of surface silanol groups during modification was evaluated using techniques of FTIR and 29 Si CP/MAS NMR. Adsorption of water and benzene…
We study numerically the dynamic and spectral properties of a one-dimensional quasi-periodic system, where site energies are given by with denoting the k th quasiperiodic lattice site. When is given by the reciprocal lattice vector with n and m being successive Fibonacci numbers, the variance of the wavepacket is foun…
Catalytic wet-oxidation of a model domestic wastewater was carried out, and improvement of the performance of the previously developed Mn/Ce and Ru/Ce catalysts was attempted. Combination of both catalysts resulted in an increase in the catalytic activity; Ru/Mn/Ce (1/9), which had an atomic ratio of Mn to Ce of 1/9 a…
Oligodeoxynucleotides containing an alkylporphyrin linked to the phosphate groups of DNA via oxypropyl chains have been synthesized. To our knowledge, these are the first porphyrin−nucleic acid conjugates bearing the porphyrin embedded in the backbone of DNA. Chain assembly was achieved by automated solid-phase synthe…
The structure and thermal decomposition of unsupported and titania-supported 12-phosphoromolybdic acid (HPMo) and its Co and Ni salts have been studied by different techniques including X-ray diffraction, thermogravimetric analysis, FT-infrared, Raman, and X-ray spectroscopic techniques. The transformation of heteropo…
Describing the theoretical aspects of chemistry and microstructure that affect mechanical properties, this work offers coverage of ceramic mechanical property measurement techniques for use in component design as well as lifetime and reliability predictions. It presents procedures from both room- and elevated-temperat…
The photoluminescence behavior of single crystals of Tl[Ag(CN) 2 ] has been studied as a function of temperature. The 10 K spectra show a broad emission centered at about 420 nm and two excitation maxima at 301 and 314 nm. Exciting with each of these maxima gives a different temperature dependence for the correspondin…
There are many clinical situations in which a large tissue mass is required to replace tissue lost to surgical resection (e.g., mastectomy). It is possible that autologous cell transplantation on biodegradable polymer matrices may provide a new therapy to engineer large tissue which can be used to treat these patients…
We propose a new method for (global) Hurst exponent determination based on wavelets. Using this method, we analyze synthetic data with predefined Hurst exponents, fracture surfaces and data from economy. The results are compared with those obtained from Fourier spectral analysis. When many samples are available, the w…
“Naked” colloidal gold solutions have been prepared in toluene using a two-phase system. The phase-transfer reagent used, a quaternary ammonium bromide salt (R 4 N + Br - ), is specifically adsorbed on the clusters through the formation of surface ion pairs, probably with the Br - ion attached to the Au surface. The s…
An unusual luminescent inorganic oxide, Sr2CeO4, was identified by parallel screening techniques from within a combinatorial library of more than 25,000 members prepared by automated thin-film synthesis. A bulk sample of single-phase Sr2CeO4 was prepared, and its structure, determined from powder x-ray diffraction dat…
X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) have been used to characterize a series of Cu/Cr/Al 2 O 3 catalysts prepared by stepwise incipient wetness impregnation of first chromium followed by copper (designated “CuCr y ”). The copper loading was held constant at 8 wt % CuO, and chromium loadin…
Catalytic epoxidation of olefins with H2O2 and t-BuOOH has been studied in the presence of a water-soluble iron(III) porphyrin complex, (5,10,15,20-tetrakis(2,6-dichloro-3-sulfonatophenyl)porphinato)iron(III) [Fe(TDCPPS)], in buffered aqueous solutions. Epoxides are the predominant products at low pH values, and the f…
The X-ray structures of the two monodimensional systems of formula [Mn(L) 2 (N 3 ) 2 ] n in which L = 3-ethylpyridine ( 1 ) or 2-hydroxypyridine ( 2 ) have been determined. Crystal data: 1, formula C 14 H 18 MnN 8, monoclinic P 2 1 / n, a = 10.210(5) Å, b = 15.460(6) Å, c = 10.880(4) Å, β = 95.86(3)°, Z = 4; 2, formul…
Mono- and multilayers of cadmium sulfide (CdS) nanoparticles were fabricated on a gold substrate covered with alkanedithiol self-assembled monolayers (SAMs) by an alternate immersion of the substrate into ethanolic solutions of dithiol, i.e., 1,6-hexanedithiol or 1,10-decanedithiol, and dispersion of CdS nanoparticles…