C.A. Christensen、Andrei S. Batsanov、Martin R. Bryce 等 4 位作者2001-04-14The Journal of Organic Chemistry
We report the synthesis of cyclophanes 18-20 by ester-forming macrocyclization reactions of diols 15 and 16 with 1,4-benzenedicarbonyl chloride. Compounds 18 and 19 display a two-electron, quasireversible oxidation wave in the cyclic voltammogram to yield the dication species at E(ox)(pa) 0.52 and 0.47 V, respectively…
Porphyrin and Phthalocyanine ChemistrySynthesis and Properties of Aromatic CompoundsPhotochromic and Fluorescence Chemistry
Ina Voigt、Frank Simon、Kathrin Estel 等 4 位作者2001-04-14Langmuir
Structure and surface polarity properties of poly(vinylformamide- co -vinylamine) (PVFA- co -PVAm)/silica hybrid materials are investigated by means of electrokinetic measurements, atomic force microscopy (AFM), and solvatochromic probes. AFM measurements show the complete covering of the silica surface with the PVFA-…
Conducting polymers and applicationsPhotochemistry and Electron Transfer StudiesAnalytical Chemistry and Sensors
Sergio Ravasio、Bruno Curti、Maria A. Vanoni2001-04-14Biochemistry
Glutamate synthase is a complex iron-sulfur flavoprotein that catalyzes the reductive transfer of the L-glutamine amide group to C(2) of 2-oxoglutarate, forming two molecules of L-glutamate. The bacterial enzyme is an alphabeta protomer, which contains one FAD (on the beta subunit, approximately 50 kDa), one FMN (on t…
Metabolism and Genetic DisordersEnzyme Structure and FunctionAmino Acid Enzymes and Metabolism
Gregory A. Rechtsteiner、Oliver Hampe、Martin F. Jarrold2001-04-14The Journal of Physical Chemistry B
A novel laser photolysis source has been used to synthesize hydrogen-terminated silicon clusters Si n H x +, where n ≤ 50. Using mass spectrometry, the hydrogen content of the Si n H x + clusters with n = 10−30 was measured as a function of temperature from 300 to 950 K. For n = 10−22 at the lower temperatures, there…
Semiconductor materials and devicesSilicon Nanostructures and PhotoluminescenceNanowire Synthesis and Applications
Yongjun Chen、E. T. Kang、K. G. Neoh 等 4 位作者2001-04-14Macromolecules
Chemical modification of the argon plasma-pretreated Si(100) surface by UV-induced surface graft polymerization with either glycidyl methacrylate (GMA) or glycidyl acrylate (GA) was carried out. The GA graft polymerized Si substrate was further subjected to coupling reaction with aniline (An) and finally oxidative gra…
Advanced Sensor and Energy Harvesting MaterialsConducting polymers and applicationsAnalytical Chemistry and Sensors
Angelos Michaelides、P. Hu2001-04-14OpenAlex
The study of catalytic behavior begins with one seemingly simple process, namely the hydrogenation of O to H2O on platinum. Despite the apparent simplicity its mechanism has been much debated. We have used density functional theory with gradient corrections to examine microscopic reaction pathways for several elementa…
Advanced Chemical Physics StudiesElectrocatalysts for Energy ConversionCatalytic Processes in Materials Science
Oliver S. Wenger、Hans U. Güdel2001-04-13The Journal of Physical Chemistry B
Single crystals of Ti 2+ doped NaCl were grown by the Bridgeman technique. High resolution variable temperature absorption, continuous-wave emission, and time-dependent measurements were performed for the spectroscopic characterization of the title compound. At T < 100 K excitation of Ti 2+:NaCl in the red spectral re…
Luminescence Properties of Advanced MaterialsPerovskite Materials and ApplicationsQuantum Dots Synthesis And Properties
Fu Qiang Huang、James A. Ibers2001-04-13Inorganic Chemistry
The alkali metal/group 4 metal/polychalcogenides Cs(4)Ti(3)Se(13), Rb(4)Ti(3)S(14), Cs(4)Ti(3)S(14), Rb(4)Hf(3)S(14), Rb(4)Zr(3)Se(14), Cs(4)Zr(3)Se(14), and Cs(4)Hf(3)Se(14) have been synthesized by means of the reactive flux method at 823 or 873 K. Cs(4)Ti(3)Se(13) crystallizes in a new structure type in space group…
Crystal Structures and PropertiesIron-based superconductors researchInorganic Chemistry and Materials
S. Fakirov、Ognian Samokovliyski、Norbert Stribeck 等 9 位作者2001-04-13Macromolecules
The nanostructure deformation mechanism of a predrawn and annealed blend of poly(ethylene terephthalate) (PET) and polyethylene (PE) (PET/PE: 50/50 by wt %) was studied. For the first time six-point small-angle X-ray scattering (SAXS) patterns were observed as a function of elongation in the investigation of a drawn p…
Polymer crystallization and propertiesPolymer Nanocomposites and PropertiesFiber-reinforced polymer composites
Christine C. Dupont‐Gillain、Paul G. Rouxhet2001-04-13Nano Letters
A strategy was developed to create a modulable polymer surface architecture (topography, chemical composition) at the nanometer scale. Therefore, collagen was first adsorbed on a poly(methyl methacrylate) (PMMA) substrate and dried at high or low rate to produce continuous or discontinuous layers, respectively. Soluti…
Surface Modification and SuperhydrophobicityPolymer Surface Interaction StudiesNanofabrication and Lithography Techniques
Philip G. Harrison、Wayne Daniell2001-04-13Chemistry of Materials
Chromium-promoted ceria catalyst materials have been prepared by three routes: impregnation of ceria gel using an aqueous solution of CrO 3 (Cr(VI)/CeO 2 -imp), impregnation of ceria gel using an aqueous solution of chromium(III) nitrate (Cr(III)/CeO 2 -imp), and coprecipitation from an aqueous solution containing bot…
Catalytic Processes in Materials ScienceCatalysis and Oxidation ReactionsNanomaterials for catalytic reactions
Lloyd M. Robeson、Robert A. Berner2001-04-13Journal of Polymer Science Part B Polymer Physics
Abstract Polymer blend technology has been one of the most investigated areas in polymer science in the past 3 decades. The one area of polymer blends that has been virtually ignored involves simple emulsion blends, although several articles have recently appeared that address film formation and mechanical characteris…
Polymer crystallization and propertiesMaterial Dynamics and PropertiesBlock Copolymer Self-Assembly
Kui-Xiang Ma、Tai‐Shung Chung2001-04-13The Journal of Physical Chemistry B
Novel fluorinated main-chain liquid crystalline/crystalline polymers were prepared through thin film polymerization. Two polymer systems were studied: one from 2,6-acetoxynaphthoic acid (ANA), acetoxyacetanilide (AAA), and 4,4‘-(hexafluoroisopropylidene)bis(benzoic acid) (6F acid) and the other from ANA, hydroquinone…
Surface Modification and SuperhydrophobicityAdvanced Sensor and Energy Harvesting MaterialsAdhesion, Friction, and Surface Interactions
T.E Paxton、Athanassios Sambanis、Ronald W. Rousseau2001-04-13Langmuir
Treatment of vessel surfaces is common practice in many protein crystallization protocols. The research reported here shows that such treatments can have a significant effect on the resulting kinetics of protein crystallization. Untreated and silanized low-protein-binding polystyrene wells were used in batch isotherma…
Protein Structure and DynamicsEnzyme Structure and FunctionCrystallization and Solubility Studies
Jarugu Narasimha Moorthy、Prasenjit Mal、Ramalingam Natarajan 等 4 位作者2001-04-13Organic Letters
[reaction: see text] All of the crystalline o-anisaldehyde derivatives 1 and 3 change to brick-red color upon brief exposure to UV-vis radiation. The red color, attributed to (E)-xylylenol, is remarkably persistent for hours (ca. 10 h) in the case of 1c; such a long lifetime for the reactive o-xylylenols is unpreceden…
Radical Photochemical ReactionsPorphyrin and Phthalocyanine ChemistryPhotochromic and Fluorescence Chemistry
Aleksandra Drozd-Rzoska、Sylwester J. Rzoska、J. Zioło 等 4 位作者2001-04-13Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics
Results presented give evidence of the existence of quasicritical, fluidlike behavior in the isotropic phase of 4-cyano-4-pentyl-biphenyl (5CB) for frequencies ranging from the static to the ionic-dominated [low-frequency (LF)] region. Despite the boost of dielectric permittivity on lowering the frequency below 1 kHz,…
Liquid Crystal Research AdvancementsMaterial Dynamics and PropertiesSurfactants and Colloidal Systems
V. Carbone、G. Cipparrone、Giovanna Russo2001-04-13Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics
An $s\ensuremath{-}\mathrm{p}\mathrm{o}\mathrm{l}\mathrm{a}\mathrm{r}\mathrm{i}\mathrm{z}\mathrm{e}\mathrm{d}$ laser beam that impinges at small incidence angle on a homeotropically aligned nematic liquid crystal produces very interesting nonlinear phenomena. In this paper, we show that, due to the symmetry of the sys…
Liquid Crystal Research AdvancementsNonlinear Dynamics and Pattern FormationPlant Reproductive Biology
H. S. Jeon、Alan I. Nakatani、Erik K. Hobbie 等 4 位作者2001-04-13Langmuir
We investigate the effect of phase inversion on the domain morphology and rheological properties of phase-separated polybutadiene/polyisoprene blends using optical microscopy, light scattering, and rheometry. Two different blends, low-vinyl polybutadiene/low-vinyl polyisoprene (LPB/LPI) and low-vinyl polybutadiene/hig…
Polymer crystallization and propertiesPolymer Nanocomposites and PropertiesFiber-reinforced polymer composites
Sébastien G. Gouin、Françoise M. Winnik2001-04-13Bioconjugate Chemistry
The level of conjugation of diethylenetriaminepentaacetic acid (DTPA) to the polysaccharide sodium hyaluronan (HA) has been measured by a colorimetric assay, isothermal titration calorimetry (ITC), and (1)H NMR spectroscopy. The colorimetric assay is based on the red shift, upon complexation with gadolinium ion (Gd3+)…
Molecular Sensors and Ion DetectionLanthanide and Transition Metal ComplexesAnalytical Chemistry and Sensors
Xu-Dong Huang、S. H. Goh2001-04-13Macromolecules
The isothermal crystallization of poly(ethylene oxide) (PEO), single-C 60 -end-capped PEO (FPEO), and double-C 60 -end-capped PEO (FPEOF) has been evaluated using polarized optical microscopy (POM) and differential scanning calorimetry (DSC). Comparison studies were also made on a physical mixture of PEO and C 60 with…
Polymer crystallization and propertiesPolymer Nanocomposites and Propertiesbiodegradable polymer synthesis and properties