Materials Literature
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This review systematizes the data on the effect of intramolecular spin–orbit perturbations on the photophysics of organic molecules introduced by heavy atoms (the intramolecular, or 'internal', heavy-atom effect). The focus is on two classes of compounds: (1) halogenated derivatives of aromatic and heteroaromatic comp…
In this paper, dielectric permittivity of dielectric mixtures is discussed in view of the spectral density representation method. A distinct representation is derived for predicting the dielectric properties [Tuncer E 2005 J. Phys. Condens. Matter 17 L125]. In order to illustrate the strength of the representation and…
We have observed tunable negative differential resistance (NDR) in scanning tunneling spectroscopy measurements of a double layer of C60 molecules on a metallic surface. Using a simple model we show that the observed NDR behavior is explained by voltage-dependent changes in the tunneling barrier height.
The dielectric alpha relaxation is the dielectric manifestation of the glass transition. In spite of this fact, the more commonly used models, the Arrhenius model and the Williams--Landel--Ferry model, do not take into account the structural state of the system to modelize this relaxation. In thermally stimulated disc…
Recently an interesting multi-ferroic system PbVO3 [Chem. Mater. 2004] was successfully prepared using a high-pressure and high-temperature technique. The crystallographic features were reported. In this note we concentrate on the theoretical XANES spectra by considering the K-edge of Vanadium. The tetragonality [c/a=…
Using first principles calculations we have studied the formation energies, electron and hole affinities, and electronic levels of intrinsic point defects in zircon. The atomic structures of charged interstitials, vacancies, Frenkel pairs, and antisite defects are obtained. The limit of high concentration of point def…
We report first principles density functional studies using plane wave basis sets and pseudopotentials and all-electron linear augmented plane wave (LAPW) of the relative stability of various ferroelectric and antiferroelectric supercells of PMN $(\mathrm{Pb}{\mathrm{Mg}}_{1∕3}{\mathrm{Nb}}_{2∕3}{\mathrm{O}}_{3})$ for…
Novel carbon nanotube-metal cluster structures are proposed as prototype systems for molecular recognition at the nanoscale. Ab initio calculations show that already the bare nanotube cluster system displays some specificity because the adsorption of ammonia on a carbon nanotube-Al cluster system is easily detected el…
Spontaneous formation and efficient stabilization of gold nanoparticles with an average diameter of 7 approximately 20 nm from hydrogen tetrachloroaureate(III) hydrate (HAuCl4.3H2O) were achieved in air-saturated aqueous poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymer solu…
We measure velocity profiles in water flowing through thin microchannels, using particle image velocimetry combined with a nanopositioning system. From the velocity profiles, we determine the slip lengths in two cases: Smooth hydrophilic glass surfaces, and smooth hydrophobic glass surfaces, grafted with a monolayer o…
We present a detailed investigation on optical properties of high-pressure phase ZnO in $B1$ (NaCl) and $B2$ (CsCl) structures, including dielectric function, refractive index, absorption, and electron energy-loss spectrum. Theoretical calculations are performed using the ab initio pseudopotential density functional m…
The exposure of a mixture of 1 mM HAuCl4 and 1 mM AgNO3 solutions to different amounts of fungal biomass (Fusarium oxysporum) results in the formation of highly stable Au–Ag alloy nanoparticles with dimensions of 8–14 nm depending on metal molar fraction (see image). The amount of cofactor NADH released by the F. oxys…
Heretofore disconnected experimental observations are combined with a theoretical study to develop a model of the chemical composition of the edges of graphene sheets in both flat and curved sp(2)-hybridized carbon materials. It is proposed that under ambient conditions a significant fraction of the oxygen-free edge s…
Two methodic concepts, symmetric and asymmetric Ostwald ripening, are elucidated by solution-route syntheses of oxide and sulfide semiconductors. While the original shape of a crystallite aggregate forms the exterior appearance, the preorganization of the crystallites determines the ultimate interior space structure o…
Various proteins adsorb spontaneously on the sidewalls of acid-oxidized single-walled carbon nanotubes. This simple nonspecific binding scheme can be used to afford noncovalent protein-nanotube conjugates. The proteins are found to be readily transported inside various mammalian cells with nanotubes acting as the tran…
Abstract The miscibility of blends of chitosan and hydroxyethylcellulose in a 2% acetic acid solution was studied by viscometry, densitometry, and refractometry at 35°C. The data suggest that the blends were completely miscible in all proportions. Further, the membranes were fabricated from concentrated blend solution…
Abstract A nonradiative dielectric waveguide (NRD) embedded in a metamaterial with negative permittivity or permeability is proposed and theoretically characterized in this work. This dielectric waveguide structure is inherently nonradiating at bends and discontinuities, since metamaterials with negative permittivity…
Abstract Summary: Three‐dimensionally ordered macroporous (3DOM) syndiotactic polystyrenes with pore size in the range of 71–286 nm were fabricated by means of silica templates using (dbm) 2 Ti(OPh) 2 /MAO catalytic system. The resulting materials were characterized by NMR, SEM, powder X‐ray diffraction, GPC and DSC.…
Abstract Summary: The present communication reports the first use of electron tomography in reconstructing the three‐dimensional morphology in thermoplastic elastomer blends. The blends investigated were dynamically vulcanized blends of ethylene‐propylene‐diene (EPDM) rubber/poly(propylene)/oil and polystyrene‐ block…
A new method for fluorescence imaging based on a polymeric photobase generator containing oxime-urethane groups was developed via the use of fluorescamine, a prefluorescent amino-group dye. The fluorescent image obtained is stable and has a high contrast and good resolution (see Figure). In addition, it is possible th…