Materials Literature
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Using density functional theory, we calculate the charge redistribution incurred upon forming multiwall carbon nanotubes, or by sandwiching initially isolated single-wall nanotubes between graphene layers. In these systems, we observe a significant charge transfer between the \ensuremath{\pi} electron system of the tu…
In this paper we study Peierls instabilities for a half-filled two-dimensional tight-binding model with nearest-neighbour hopping $t$ and next nearest-neighbour hopping $t'$ at zero and finite temperatures. Two dimerization patterns corresponding to the same phonon vector $(π, π)$ are considered to be realizations of…
In this paper, a new type of soluble polyimide/silica (PI/SiO 2 ) hybrid was prepared by the sol−gel process. The coupling agent γ-glycidyloxypropyltrimethoxysilane (GOTMS) was chosen to enhance the compatibility between the polyimide (PI) and silica (SiO 2 ). Furthermore, the effects of the coupling agent on the morp…
We have studied the ground state of a simple cubic magnetic cluster, which contains a spin s at each corner site. The ground state of such cluster depends on the competition between nearest, next-nearest and next-next-nearest-neighbor exchange interactions. We have calculated the "phase" diagrams for the Izing cluster…
Although considerable effort has been dedicated to the controlled synthesis of nanoparticles with classical inorganic structures, there are few reports on the formation of nanoscale materials based on supramolecular compounds such as transition metal coordination polymers. Here we describe the synthesis of crystalline…
The electronic structure of single-walled carbon nanotubes (SWNTs) is investigated by transmission spectroscopy of thin films. Hole-doping of SWNTs, as a result of purification, leads to free carrier absorption in the far-IR spectral range. Thermal cycling de-dopes SWNTs, transferring spectral weight from the far-IR t…
A superlattice structure commonly existing in ${\mathrm{P}\mathrm{b}(\mathrm{M}\mathrm{g}}_{1/3}{\mathrm{Nb}}_{2/3}{)\mathrm{O}}_{3}$ was detected by selected-area electron diffraction (SAED) and high-resolution electron microscopy (HREM). The computer simulation of the SAED and HREM showed that this superlattice stru…
The adsorption sites of CO on the reduced ${\mathrm{RuO}}_{2}(110)$ surface were determined by employing the techniques of density-functional theory calculations and quantitative low-energy electron diffraction. On the mildly reduced ${\mathrm{RuO}}_{2}(110)$ surface, where the bridging oxygens are removed, twofold (2…
We report the vibrational properties of quasi-two-dimensional ${\mathrm{K}}_{2}{\mathrm{V}}_{3}{\mathrm{O}}_{8}$ as a function of temperature. Based on the splitting of the ${990\ensuremath{-}\mathrm{c}\mathrm{m}}^{\mathrm{\ensuremath{-}}1}$ c-axis phonon mode into a doublet, we conclude that the 110-K transition is d…
Abstract The aim of this paper is to discuss a boundary element formulation for non‐linear structural problems involving localization phenomena. In order to overcome the well‐known mesh dependency observed in local plasticity, a gradient plasticity model is used. An implicit boundary element formulation is proposed an…
Full elucidation for stable, colorless, and meta-stable colored structures of a new spirobenzothiopyran has been achieved both in the solid state and in a solution. 1',3',3'-Trimethyl-6-nitrospiro[(2H)-1-benzothiopyran-2,2'-indoline] with an ester group as a substituent at the 8-position of 1-sp shows photochromism. T…
Coupling reactions of 2,2,6,6-tetramethylpiperidinyloxy-terminated polystyrene (PS-TEMPO) using divinylbenzene (DVB) as a linking agent were performed in the presence of 4-vinylbenzyl glucoside peracetate ( 1a) and 4-vinylbenzyl maltohexaoside peracetate ( 1b) . To prepare core-glycoconjugated star-shaped polymers wit…
Although the title compound crystallizes as a stable conglomerate without any detectable solid solution, particles in the shape of single crystals grown from the racemic aqueous solution without stirring contain almost no enantiomeric excess. From stereoselective dissolution experiments carried out in a solution satur…
The scattering of a diblock copolymer micelle has been simulated using Monte Carlo techniques. The scattering is analyzed using a novel model, where the corona is represented as a dilute/semidilute polymer solution with a radial profile. This approach decouples the scattering due to interaction and connectivity induce…
The phase diagram of coexisting liquid−liquid phase separation (LLPS) and crystallization in nearly isorefractive blends of statistical ethylene/hexane (PEH) and ethylene/butene (PEB) copolymers has been investigated. A variety of techniques that exploit crystallization-induced contrast, such as diffuse light scatteri…
A spontaneous or field induced "hidden" phase transition with antiferromagnetic-to-ferromagnetic reordering is disclosed in multiply frustrated hexagonal ErMnO3. It is revealed by Faraday rotation and second harmonic generation as sublattice-sensitive probes to the Er and Mn systems. The acquired phase diagram in the…
The hydrolysis of magnesium methoxide in methanol or methanol−toluene solvents with a water-to-methoxide molar ratio of 2 has been studied. The gel obtained from the hydrolysis of magnesium methoxide appears to be polymeric based on the mass fractal dimensions and TEM micrographs. The presence of toluene accelerates t…
The CO 2 sorption and the consequent swelling of un-cross-linked poly (dimethylsiloxane) (PDMS) have been measured simultaneously at high pressure using in-situ ATR (Attenuated Total Reflectance)−IR spectroscopy. The absorbance of the ν 3 (2335 cm -1 ) band of CO 2 dissolved in PDMS was used to determine quantitative…
A number of equations for the melting temperature dependence on pressure, ${T}_{m}(P),$ based on the two- and one-phase approaches to melting have been obtained. All melting curves have the form ${T}_{m}=F(P)D(P),$ where $F(P)$ is the Simon (rising) melting equation and $D(P)$ is the damping function, which asymptotic…
The chain length dependence of excitation energies of oilgomers of polyene, p -phenylene, pentafulvene, cyclopentadiene, pyrrole, furan, silole, phosphole, and thiophene was studied employing the time-dependent density functional theory with B3LYP functional. Band gaps and effective conjugation lengths of the correspo…