Materials Literature
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The filling of carbon nanotubes, which vary in diameter and morphology, is directly observed by molecular dynamics computer simulation with a potential model which thermodynamically favors a four-coordinate bulk crystal structure. Inorganic nanotube (INT) structures form which are based on percolating hexagonal nets.…
The Kovacs protocol, based on the temperature shift experiment originally conceived by A. J. Kovacs for glassy polymers, is implemented in an exactly solvable dynamical model. This model is characterized by interacting fast and slow modes represented, respectively, by spherical spins and harmonic oscillator variables.…
A new method for high-resolution analyses of hair surface charge density under ambient conditions is presented in this paper. Electrostatic force microscopy (EFM) is used here to analyze changes in surface charge density in virgin hair, bleached hair, and hair treated with a cationic polymer. The atomic force microsco…
A series of undoped and doped barium titanate powders were prepared and examined by: X‐ray diffraction, high‐resolution scanning electron microscopy, transmission electron microscopy, particle size, ζ‐potential, specific surface area, differential scanning calorimetry (DSC), impedance spectroscopy, and secondary‐ion m…
Stress–strain curves of (1− x )BiFeO 3 – x PbTiO 3 compositions with x =0.2, 0.3, and 0.35 were determined under uniaxial loading to assess the material's potential for domain switching. The composition with x =0.35 provides the highest remanent strain, with more than 0.2% coupled with a strong tendency to relaxation.…
The effect of additions of ≤1 mol% Al 2 O 3 on abnormal grain growth in BaTiO 3 sintered for periods of ≤60 min at 1350°C has been studied. Addition of ≤0.2 mol% Al 2 O 3 caused an increase in the nucleation and growth rates of abnormal grains, with further additions causing a decrease. This behavior is explained by i…
Eleven silicon phthalocyanines which can be grouped into two homologous series [SiPc[OSi(CH3)2(CH2)(n)N(CH3)2]2, n = 1-6 (series 1), and SiPc[OSi(CH3)2(CH2)3N((CH2)(n)H)2]2, n = 1-6 (series 2)] as well as an analogous phthalocyanine, SiPc[OSi(CH3)2(CH2)3NH2]2, were synthesized. The ground state absorption spectra, the…
Mono- and bis-oxadisilole-fused isobenzofurans were first synthesized and isolated. A series of mono-, bis-, and tris-oxadisilole-substituted acenes were then synthesized by benzyne Diels-Alder reactions with the isobenzofurans. The photophysical, redox, and thermal properties of these new acenes were characterized.
The kinetics and thermodynamics of lysozyme precipitation in ammonium sulfate solutions at pH 4 and 8 and room temperature were studied. X-ray powder diffraction (XRD) was used to characterize the structure of lysozyme precipitates. It was found that, if sufficient time was allowed, microcrystals developed following a…
The effects of different annealing atmospheres on the chemical surface structure of HfO 2 gate dielectric layers have been evaluated in terms of the improvement in the transconductance ( g m ), current on/off ratio ( I on / I off ), and carrier mobility (μ e ) of a back-gated ZnO nanowire field-effect transistor (FET)…
Heating in air of a selected mixture of a silicone resin and alumina nanoparticles in the temperature range 1200°–1500°C yielded dense, crack‐free mullite samples. Al 2 O 3 , due to its nanometric size, proved to be very reactive toward silica, deriving from the ceramization of the preceramic polymer, leading to the f…
ZnO nanorods have been prepared with sol–gel methods using zinc acetate dihydrate in ethanol in the presence of lithium hydroxide via alkaline hydrolysis. The electron transfer behaviour at the surface and interface in ZnO nanorods was investigated by means of the surface photovoltage technique. The influence of adsor…
We investigate the enhanced alignment of lamellar microdomains under an electric field by addition of lithium chloride (LiCl) into polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) copolymers. A significant increase of dielectric contrast resulting from the formation of lithium-PMMA complexes markedly reduces th…
We report on low-temperature measurements in a fully tunable carbon nanotube double quantum dot. A new fabrication technique has been used for the top-gates in order to avoid covering the whole nanotube with an oxide layer as in previous experiments. The top-gates allow us to form single dots and control the coupling…
Nonstoichiometric orthorhombic titanium oxides (TiO x ; x =1.86–1.94) prepared by reducing the anatase titanium oxide in H 2 at 950°C are found to show large thermoelectric power. Their Seebeck coefficients are in the range −0.060 to −0.518 mV/K, and theoretical discussions are made based on the assumption that the el…
We propose a novel approach to the synthesis of photoluminescent Ge nanoparticles using reactive laser ablation. The deposition of germanium under low oxygen pressure (2–100 mTorr) yields Ge nanoparticles embedded in a Ge oxide matrix. Ge nanostructures were characterized by transmission electron microscopy, x-ray pho…
High‐energy ball milling initiates a solid‐state reaction in an equimolar mixture of TiO 2 and ZrO 2 . The first stage of ball milling induced the transformation of anatase TiO 2 to high‐pressure phase TiO 2 (II), isostructural with ZrTiO 4 . The formation of solid solutions monoclinic ZrO 2 /TiO 2 and TiO 2 (II)/ZrO…
Based on the fact that ionicity exists in chemical bonds between identical atoms in $\ensuremath{\alpha}$-boron, investigation has been performed on the influences of $X$ atoms on the ionicities of $\mathrm{B}\text{\ensuremath{-}}\mathrm{B}$ bonds in ${\mathrm{B}}_{13}{\mathrm{C}}_{2}$-like structured ${\mathrm{B}}_{y…
Abstract In this study, polystyrene (PS)/montmorillonite nanocomposites were prepared by melt intercalation, in situ polymerization, and masterbatch methods. In the masterbatch method, as the first step, a high clay content composite of PS–organoclay (masterbatch) was prepared by in situ polymerization, and then the p…
Fehler im System, nämlich Sauerstoffvakanzen in ZnO, wirken als aktive Zentren in der Hydrierung von CO zu Methanol. Nanokristallines ZnO mit hoher Sauerstoffleerstellendichte wurde aus metallorganischen Zn4O4-Vorstufen präpariert und auf seine katalytischen Eigenschaften in der Methanolsynthese untersucht.