Materials Literature
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High-resolution X-ray diffraction data show that the low-temperature superstructure of alpha-NaV2O5 has an F-centered orthorhombic 2a x 2b x 4c superlattice. A structure model is proposed, that is characterized by layers with zigzag charge order on all ladders and stacking disorder, such that the averaged structure ha…
We investigated the adsorption of a single atom, hydrogen and aluminum, on single-wall carbon nanotubes from first principles. The adsorption is exothermic, and the associated binding energy varies inversely as the radius of the zigzag tube. We found that the adsorption of a single atom and related properties can be m…
The effects of uniaxial strain on the structural, orbital, optical, and magnetic properties of ${\mathrm{LaMnO}}_{3}$ are calculated using realistic expressions for elastic energies, along with a tight-binding parametrization of the band theory and electron-phonon coupling. Tensile uniaxial strain of the order of 2% (…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTColloidal Imprinting: A Novel Approach to the Synthesis of Mesoporous CarbonsZuojiang Li and Mietek JaroniecView Author Information Department of Chemistry, Kent State University Kent, Ohio 44242 Cite this: J. Am. Chem. Soc. 2001, 123, 37, 9208–9209Publication Date (We…
A number of polyimides have gained considerable importance as high-performance polymers during the last 2 decades primarily because of their excellent thermal stability and toughness. Some applications, however, require property enhancements and the desired improvements can often be obtained through incorporation of c…
Lipophilic and hydrophilic dendra which are terminated with long alkyl chains and oligomeric poly(ethylene glycol) moieties, respectively, were synthesized, and these dendron species were used to functionalize single-wall (SWNT) and multiple-wall (MWNT) carbon nanotubes via amidation and esterification reactions. The…
Goniophotometry has enabled measurement of the angle that the surface of the cuticle (the scales) of a human hair fiber makes with the axis of the hair shaft. This measuring technique has been used to obtain the change of this scale angle with extension of a hair fiber under fixed conditions of temperature and relativ…
Abstract The effect of the solvent composition on the elasticity of strong and weak cation‐ and anion‐exchange resin beads was studied. Poly(styrene‐ co ‐divinylbenzene) resins containing sulfonic acid or quaternary ammonium groups and an acrylic acid resin crosslinked with divinylbenzene were immersed in water, NaCl…
We have conducted temperature and frequency dependent transport measurements in amorphous ${\mathrm{Nb}}_{x}{\mathrm{Si}}_{1\ensuremath{-}x}$ samples in the insulating regime. We find a temperature dependent dc conductivity consistent with variable range hopping in a Coulomb glass. The frequency dependent response in…
A comprehensive photophysical study of protonated species of (tetra-tert-butylphthalocyaninato)zinc (tBu4ZnPcHnn+, n = 0–4) is reported. Singlet and triplet state properties have been measured and discussed with reference to the effects of protonation which occur at the azomethine bridging nitrogens of the phthalocyan…
The adsorption of polymer dispersants of the polyisobutenylsuccinimide series has been studied at the solid/xylene interface. Carbon black was studied as a model solid. Adsorption isotherms were determined, the enthalpy of adsorption was measured by calorimetry, and the thickness of the adsorbed layer was obtained fro…
Enzymes of the glyoxylate-bypass pathway are potential targets for the control of many human diseases caused by such pathogens as Mycobacteria and Leishmania. Isocitrate lyase catalyses the first committed step in this pathway and the structure of this tetrameric enzyme from Escherichia coli has been determined at 2.1…
Abstract 4‐{ n ‐[4‐(4‐Nitrophenylazo)phenyloxy]alkyl}aminobenzene sulfonic acid (C n ‐ABSA, where n = 2, 4, 6, 8, or 10) as a novel dopant for conducting polymers of polyaniline (PANI) was designed and synthesized. The molecular structure of C n ‐ABSA was characterized with 1 H NMR, Fourier transform infrared, and sec…
The evolution of the dielectric α relaxation and ionic conductivity with time t r during polymerization at 60 °C of mixtures of the diepoxide DGEBA, the diamine PACM, and the diluent Decalin (DEC) or di- n -butyl phthalate (DBP) has been studied using real-time dielectric relaxation spectroscopy (DRS). Data are presen…
Reaction of organocobalt(III) porphyrins with a cobalt(II) complex of a distinguishable porphyrin or tetrapyrrole resulted in the reversible exchange of the organic axial ligand. The exchange reaction was facile in such solvents as benzene, toluene, dichloromethane, chloroform, and pyridine; was unaffected by total ex…
The previously unknown crystal structure of the C(1) subunit of the carotenoid-binding protein alpha-crustacyanin has been determined using the anomalous scattering available at 1.77 A wavelength to determine the partial structure of the S atoms intrinsic to the native protein. The resulting 'heavy-atom' phases, in co…
The synthesis of poly(vinyl hydroquinone), PVHQ, via stable free radical polymerization (SFRP) to give a low-dispersity (1.5) material is described. The electrochemical properties of the resulting material deposited as films onto glassy carbon electrodes have been investigated by cyclic voltammetry. In aqueous acetic…
A first-principles molecular dynamics study of glassy ${\mathrm{As}}_{2}{\mathrm{Se}}_{3}$ and ${\mathrm{As}}_{4}{\mathrm{Se}}_{4}$ is presented. We focus on the differences in local structure between these glasses and identify the structural elements of ${\mathrm{As}}_{4}{\mathrm{Se}}_{4}$ and present a model of the…
A series of π-conjugated rodlike polymers, poly(2,5-dialkyl p -phenyleneethynylene)s, PPE's, were synthesized with alkyl groups of n -butyl ( 4a ), n -octyl ( 4b ), n -tetradecyl ( 4c ), 2-ethylhexyl ( 4d ), and 2-cyclohexylethyl ( 4e ). Polymers with linear alkyl side groups ( 4a, 4b, and 4c ) formed gels in toluene…
The coordination environments of Ge and As atoms in ${\mathrm{Ge}}_{x}{\mathrm{As}}_{y}{\mathrm{S}}_{1\ensuremath{-}x\ensuremath{-}y}$ glasses with $x:y=1:2,$ 1:1, and 2.5:1 and with wide-ranging S contents have been studied with Ge and As K-edge x-ray absorption fine structure spectroscopy. The coordination numbers o…