Materials Literature
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Concentrated colloidal solutions of well-dispersed YVO 4:Eu nanoparticles are synthesized by precipitation reactions at room temperature and stabilized by sodium hexametaphosphate. X-ray diffraction and electron microscopy characterizations show that the crystalline nanoparticles exhibit an ellipsoidal form with two c…
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” opt…
The low-temperature annealing effect on electron field emission of tetrahedral amorphous carbon (ta-C) films was investigated. Ta-C films prepared by a filtered arc deposition technique were annealed at 400 °C for 60-120 min in a nitrogen atmosphere. The density and sp 3 content in as-grown film were 3.3 g cm -3 and ~…
Polycarbazole has been synthesized by electrochemistry. The carbazole monomer source consists either in carbazole in solution in the electrolyte or in carbazole deposited in thin film form onto the working electrode. The two families of polymers have been studied by infrared absorption, X-ray diffraction, thermal grav…
Delta(5)-3-Ketosteroid isomerase from Pseudomonas putida biotype B is one of the most proficient enzymes catalyzing an allylic isomerization reaction at rates comparable to the diffusion limit. The hydrogen-bond network (Asp99... Wat504...Tyr14...Tyr55...Tyr30) which links the two catalytic residues, Tyr14 and Asp99,…
Electron paramagnetic resonance (EPR) g tensors of 20 five- or six-coordinated d 1 metal porphyrins following the [M E(P)]−L structural motif (M = V(IV), Nb(IV), Cr(V), Mo(V); E = N, O, S, Se; P = porphyrin dianion; L = F -, Cl -, Br -, ClO 4 -, OH -, OCH 3 -, H 2 O, or not present) were computed using density functio…
The reaction between the propargyl radical (C 3 H 3 ) and NO has been investigated as a function of temperature (195−473 K) and pressure (3−100 Torr) by using color center laser infrared kinetic spectroscopy. At room temperature and below, the reaction rate was found to depend strongly on the helium buffer gas pressur…
The organized molecular structure of collagen is related to its dimensional stability. The dimensional stability of collagen arises from the interplay of various intermolecular forces such as covalent, hydrogen bonding, electrostatic interactions, hydrophobic interactions, London or van der Waals forces, and weak inte…
The grafting of hydroxy telechelic polybutadienes (HTPBD) by 2-mercaptoethanol to saturate 1,2-double bonds which enabled an increase of the OH functionality of HTPBD is presented. The functionalities of the virgin and grafted HTPBD were characterized both by 1H-NMR after silylation of the hydroxy end groups and the…
Perfluorinated polymer colloids with low refraction index are prepared via emulsion polymerization. The characterization is done using small-angle X-ray scattering and dynamic light scattering. The independently obtained particle size distributions are in remarkable mutual agreement and give evidence for the monodispe…
In an effort to design cyclic anhydride copolymers that have biodegradable characteristics and are derived from renewable resources, the copolymerization of itaconic anhydride and methacrylate-terminated poly-(L-lactic acid) (PLLA) was studied. Polymers with anhydride concentrations from 85 to 15 mol% have been synthe…
Sodium-covered silica films formed on silicon substrates are examined by X-ray photoemission spectroscopy (XPS) and X-ray absorption fine structure spectroscopy (EXAFS) in ultrahigh vacuum conditions. The presence of sodium, which diffuses within the silica matrix at 300 K results in a shift of the O 1s core level tow…
Two grades of nuclear graphite, an isotropic graphite (GCMB) and an anisotropic graphite (PGA), were thermally oxidized to high weight losses. Average values of the coefficient of thermal expansion (CTE) in the temperature range 20-600 °C for GCMB and PGA in the parallel direction were unaffected by thermal oxidation…
A microcalorimetric method is proposed to determine the contact angle of a nonwetting liquid within a mesoporous solid. It is based on the simultaneous measurement of the heat and work of wetting, as the pressure is raised. The method simply requires a previous determination of the surface area to be wetted. It allows…
Hydroxy telechelic poly( l -lactide)s of different molecular weight have been synthesized by controlled ring-opening polymerization using cyclic tin alkoxides. NMR analysis showed that the propagation proceeded through an insertion mechanism. No free hydroxyl or carboxyl end groups were detected in the polymerization…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTCatalyzed Growth of a Metastable InS Crystal Structure as Colloidal CrystalsJennifer A. Hollingsworth, Damadora M. Poojary, Abraham Clearfield, and William E. BuhroView Author Information Department of Chemistry, Washington University St. Louis, Missouri 63130-4899 Sym…
Dehydrogenation of ethylbenzene to styrene under excess carbon dioxide flow was carried out over activated carbon-supported metal oxide catalysts (Cr, Mn, Co, Ni, Mo, Ru, La, and Ce) at 823 K and W / F = 35 g of catalyst·h/mol. The highest yield of styrene (about 40%) with selectivity of above 80% was obtained using a…
Luminescence sensitivity changes in natural quartz induced by high temperature annealing: a high frequency EPR and OSL study, N R J Poolton, G M Smith, P C Riedi, E Bulur, L Bøtter-Jensen, A S Murray, M Adrian
Four different forms of jute fibers, namely untreated jute filament (UJF), sliver jute filament (SJF), bleached jute filament (BJF), and mercerized jute filament (MJF), have been subjected to tensile strength analysis following Weibull's theory. The MJF and BJF were obtained by the chemical modification of the UJF. A…
The time-evolution of a three-dimensional (3D), bicontinuous interface of a phase-separated polymer mixture in the late stage spinodal decomposition (SD) process has been studied by laser scanning confocal microscopy (LSCM) and time-resolved light scattering. The time evolution of the interface between two coexisting…