Materials Literature
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Surface modification of polypyrrole (PPY), polyaniline (PAN) and poly(3-alkylthiophene) films by ozone was studied by angle-resolved x-ray photoelectron spectroscopy (XPS). In the case of the N-containing polymers, oxidation occurs readily and mainly at the carbon atoms, resulting in the formation of CνO, CξO, COOH an…
The wear characteristics of aluminum-silicon alloys were studied using a pin-on-disk-type wear tester with different types of lubricants under fully flooded condition. Aluminum-silicon alloy pin specimens were run against the same aluminum-silicon disc surfaces. Wear tests showed that wear resistance of aluminum-silic…
To further analyze the biodegradation of polyurethane polymers, we investigated the biodegradation of low-molecular-weight N-tolylcarbamate model compounds with structures closely resembling the urethane linkages found in polyurethanes based on tolylene-diisocyanate (TDI). Soil microflora were screened for microorgani…
A nonroughened evaporated silver film was used as a substrate for a self-assembled monolayer of p -nitrothiophenol, which was then subjected to UV photopatterning. The photopattern was imaged using surface-enhanced Raman scattering (SERS). To our knowledge, this is the first report of the use of SERS to image a patter…
Supported [Rh10Se] catalyst on TiO2 converted carbon dioxide into ethanol faster (60 × 10–3 mol h–1 g cat–1) and more selectively (≈83%) than other supported Rh clusters or [Rh10Se] on other inorganic oxides, presumably due to the effects of interstitial Se and the interface of the [Rh10Se] cluster and TiO2.
A 2,3-diaminoporphyrin has been synthesised for the first time and its reaction with α-diones has been examined. Two regioselective routes to the precursor 2-amino-3-nitroporphyrins have been established. 2-Aminoporphyrins are directly nitrated on the porphyrin ring in the 3-position while 2-nitroporphyrins react with…
Regioirregular poly( p -phenylene)s (PPPs) with OCF 3, CF 3 or OCH 3 substituents ( 16a, 16b, or 16c, respectively) were synthesized via Ni(0)-catalyzed polymerization of 2-substituted-1,4-bis[[(trifluoromethyl)sulfonyl]oxy]benzenes ( 5, 8, or 10, respectively). Regioregular head − to − head PPPs with OCF 3 or CF 3 su…
Recent studies have induced a biaxial texture in lamellae-forming poly(styrene- b -ethylene propylene) diblock copolymers by applying large amplitude oscillatory shear. According to small-angle X-ray scattering, this biaxial texture consists of “parallel” lamellae (normal to lamellae aligned perpendicular to the shear…
We investigated the effects of pH, ionic strength, catalyst, and initial concentration on both decomposition of 2-chlorophenol (2-cp) and removal of total organic carbon (TOC) in aqueous solution with ultrasonic amplitude 120 μm and H 2 O 2 (200 mg/l). When the initial concentrations of 2-cp was 100 mg/l and the pH wa…
The Wilhelmy plate technique was used to measure the dynamic surface tension of poly( N -isopropylacrylamide)(poly(NIPAM)) at the air−water interface as a function of poly(NIPAM) concentration and temperature. Initial periods of a negligible decrease of the dynamic surface tension were observed at the lowest concentra…
The crystal and molecular structure of [{Cu(bpzt)}2]·3H2O [H2bpzt = 1,3-bis(pyrazol-3-yl)triazene] was determined by X-ray diffraction methods. The complex has a quasi-planar dinuclear structure with an asymmetric double pyrazolate bridge. The asymmetry results from the presence, on the C3 of each bridging pyrazolate,…
NH4NiPO4·6H2O and NH4NiPO4·H2O have been obtained by adding different concentrations of H3PO4 to dilute solutions of NiCl2·6H2O with special attention to the control of the pH in the solvent medium, which was regulated by addition of NH4OH. The NH4NiPO4·6H2O compound crystallizes in the orthorhombic Pmn21space group w…
The Ti + 2B exothermic chemical reaction was used in combination with a high‐velocity forging step to produce dense TiB 2 ‐(20 vol%)SiC composites. Densities in excess of 96 % of the theoretical were achieved for both SiC particulate and fiber additions. X‐ray diffractometry revealed the products of the reaction to be…
The degree of orientation in thermotropic liquid crystalline polymer films has been determined as a function of the draw ratio using a specially developed spectrographic birefringence technique, diffuse reflectance infrared spectroscopy (DRIFT), and wide-angle X-ray scattering (WAXS). Quantitative measurements of the…
CVD boron nitride films have been deposited at 800 °C from diborane, ammonia, and hydrogen gas mixtures, using different B 2 H 6 flow rates. The effect of the [B 2 H 6 ]/[NH 3 ] ratio in the gas mixture on the structure, composition, and the stability of the layers in humid atmospheres has been studied. For low [B 2 H…
2-Propanol decomposition at 200 °C on magnesium oxide prepared by the hydrolysis of magnesium ethoxide (sol−gel method) is reported. With hydrochloride acid, acetic acid, or ammonia as hydrolysis alkoxide catalysts, the acidity and the selectivity to propene of the catalysts follow the sequence, MgO (HCl) > MgO (aceti…
Mathematical models that have been proposed for creep in ceramics are described. Emphasis is on models involving grain boundary motion (sliding or flow). In Lifshitz models the crystalline grains elongate with strain; the elongation results from diffusion, slip, or solution and precipitation. In Rachinger models the g…
Plasma polymerization of hexamethyldisilane ([CH 3 ] 3 SiSi[CH 3 ] 3 ) and tetramethylsilane ([CH 3 ] 4 Si) has been investigated by XPS, FTIR, solid state NMR, and plasma emission diagnostics. Thin carbosilane films and powders can be deposited by this method. Hexamethyldisilane is found to undergo glow discharge pol…
The series of tetrakis(μ-N,N‘-diarylformamidinato)dinickel(II), where the aryl is the phenyl modified with various substituent (X), is synthesized and thoroughly characterized. While both the coordination geometry and the UV−vis spectra remain essentially independent of X across the series, the one-electron oxidation…
Configurational and ligand conformational influences on the kinetics of (1)A(1) right harpoon over left harpoon (5)T(2) spin crossover in the Fe(II) complex with the novel tripodal ligand, 1,1,1-tris((N-(2-pyridylmethyl)-N-methylamino)methyl)ethane (tptMetame), have been explored. Despite having six chelate rings and…