Materials Literature
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Mechanisms for carrier generation in zinc antimonate (ZnSb 2 O 6 ) with a wide band gap were examined in relation to its crystallinity. ZnSb 2 O 6 prepared by the reaction of Sb 2 O 5 sol and 3ZnCO 3 ·4Zn(OH) 2 was sintered at 893, 1173, and 1393 K, and characterized by X‐ray diffraction (XRD), electrical conductivity…
Here we report the formation and spectroscopic properties of cadmium sulfide (CdS) nanocrystal systems: individual nanocrystal and CdS aggregates. The optical absorption and luminescence spectra of the aggregated CdS nanocrystals and individual nanocrystal show exciton aggregate and individual exciton characteristics.…
The thermal stability of ultrasmall $0.4\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ single-walled carbon nanotubes (SWNTs) are studied by means of Raman-scattering measurements under a vacuum. The $0.4\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ SWNTs are very stable when they are confined inside the channels of the $\mathrm{A…
Abstract Cyclohexanone–formaldehyde resins were modified in situ with α,ω‐diamine polydimethylsiloxanes and α,ω‐dihydroxy polydimethylsiloxanes. Melting points, solubilities in organic solvents, gel permeation chromatographs, Fourier transform infrared spectra, and NMR spectra of the modified resin were determined, an…
The thermodynamic conductivity data ${\ensuremath{\sigma}}_{\mathrm{ac}}(f,T)$ of the acceptor $({\mathrm{Ca}}^{2+})$-doped $\mathrm{Sr}{\mathrm{Bi}}_{2}{\mathrm{Ta}}_{2}{\mathrm{O}}_{9}$, a fatigue-free ferroelectric, was subjected to a modified Jonscher's power law ${\ensuremath{\sigma}}^{\ensuremath{'}}(f)={\ensure…
A versatile synthetic approach to cadmium chalcogenide nanoparticles in the mesopores of SBA-15 silica as a host matrix was developed. The use of cadmium organochalcogenolates of the type Cd(XPh)(2).TMEDA (X = S, Se, Te) allowed the preparation of nanoparticles of all three cadmium chalcogenides following the same exp…
The optical properties of sol-gel synthesized porous silica excited by synchrotron radiation in the 4-10 eV range of samples with different porosity at 8 K and room temperature are reported. The analysis of the ultraviolet photoluminescence indicate the contributions of two different emitting centers. The spectral and…
We study the aging of a colloidal laponite glass by measuring the dynamic structure factor of dilute embedded tracer particles on micrometric length scales. We show that an initial aging regime, where the decay time grows exponentially with aging time t(w), tau approximately exp (gamma t(w)), is followed by a full agi…
We have fabricated (La,Sr)MnO3 (LSMO)-based magnetic tunnel junctions with Ru-doped LSMO (LSMRO) film used as one of the electrodes. The Ru doping enhances the coercivity of LSMO, resulting in a sharp steplike tunnel magnetoresistance (TMR) response with a high contrast in the coercive field (Hc) for magnetization rev…
Ring sulfonation of a poly(thienothiophene) produces a stable, low‐bandgap (< 1.2 eV), water‐processable, intrinsically conductive polymer. The optical properties of the polymer can be easily modified by varying the sulfonation level and optical‐bandgap tuning can also be achieved through the use of a polycation. W…
Recently we reported the formation of a quasiperiodic Cu thin film on the fivefold icosahedral $\mathrm{Al}\text{\ensuremath{-}}\mathrm{Pd}\text{\ensuremath{-}}\mathrm{Mn}$ quasicrystal using scanning tunneling microscopy, low energy electron diffraction, and Auger electron spectroscopy. Here we provide details pertai…
Adequate oral bioavailability is a key pre-requisite for any orally administered drug to be systemically effective. Dissolution (release of the drug from the dosage form) is of primary importance for all conventionally constructed, solid oral dosage forms in general, and for modified-release dosage forms in particular…
Asymmetric, potentially pentadentate ligands (H(2)L(3)) are formed by subsequent condensation of a semicarbazide and benzoylhydrazine on 2,6-diacetylpyridine. Two equivalents of H(2)L(3) reacts with CeCl(3).7H(2)O, Ce(SO(4))(2).4H(2)O, or EuCl(3).6H(2)O under formation of [Ln(III)(HL(3))(2)](+) cations (Ln = Ce, Eu) w…
Protonation of p-xylylaminomethylferrocene (1) and n-hexylaminomethylferrocene (2) by HCl and NH(4)PF(6) forms the ferrocenylmethyl(alkyl)ammonium salt. Inclusion of the compounds by dibenzo[24]crown-8 (DB24C8) produces [2]pseudorotaxanes, [(DB24C8)(1-H)](+)(PF(6)) and [(DB24C8)(2-H)](+)(PF(6)), respectively. X-ray di…
The method for the evaluation of the distribution of carbon nanotube sizes from the static adsorption measurements and computer simulation of nitrogen at 77 K is developed. We obtain the condensation/evaporation pressure as a function of pore size of a cylindrical carbon tube using Gauge Cell Monte Carlo Simulation (G…
We study routes toward the construction of 2D colloidal pyramids. We find that magnetic beads may self-assemble into pyramids near a nonmagnetic 1D boundary as long as the number of beads in the pyramid does not exceed 10. We have also found that a strong magnetic field gradient could act as a boundary, thus assisting…
Abstract A novel positive‐type photosensitive polyimide (PSPI) with a low dielectric constant was developed. The PSPI system was composed of soluble block PI (Bco‐PI) with a hydroxy group and diazonaphthoquinone as a photoreactive compound. The base Bco‐PI was prepared by a direct one‐pot polycondensation of 2,2‐bis(3…
Abstract The degradation kinetics of poly(3‐hydroxybutyrate‐ co ‐3‐hydroxyhexanoate), a member of the Nodax family of polymers, were investigated using transient constant shear rate and dynamic time sweep rheological tests. The rate of chain scission at several times and temperatures was correlated with viscosity data…
Our previous results indicated that noncrystalline regions in a regenerated cellulose film comprised at least three domains engaged in different manners of molecular assembly [Kondo et al. In Cellulose Derivatives; Heinze, T. J., Glasser, W. G., Eds.; ACS Symposium Series 688; American Chemical Society: Washington, DC…
The density-dependent distribution function of the orientation of the long axis of rod-like colloidal particles in the liquid crystalline nematic phase is numerically calculated as the solution of a nonlinear integral equation. From this solution, which is obtained by an iterative method that is explained in detail, t…