Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
The local dynamics of water and its effect on the segmental mobility in the amorphous phase of polyamide 6,6 have been investigated. At 300 K and below, where the polymer segments undergo no significant motion (displacements below 2 Å, no reorientation) in the time scale of the simulation, water molecules exhibit most…
Abstract The thermal behavior and intermolecular interactions of blends of poly(3‐hydroxybutyrate) (PHB) and maleated PHB with chitosan were studied with differential scanning calorimetry, Fourier transform infrared (FTIR), wide‐angle X‐ray diffraction (WAXD), and X‐ray photoelectron spectroscopy (XPS). The difference…
Bismuth-layer-structured Bi 4 Ti 3- x W x O 12+ x (BiTW) ceramics, where x =0, 0.02, 0.04, 0.08, 0.10 and 0.20, have been prepared by a conventional sintering technique. The conducting, dielectric and ferroelectric properties of BiTW were investigated. The microstructure results revealed randomly oriented grains with…
Eight different flavin derivatives have been synthesized and the electronic effects of substituents in various positions on the flavin redox chemistry were investigated. The redox potentials of the flavins, determined by cyclic voltammetry, correlated with their efficiency as catalysts in the H2O2 oxidation of methyl…
The first aqueous preparation of luminescent CdS QDs from a single precursor is reported. These water-soluble CdS quantum dots with tunable sizes between 25 and 40 Å were produced from a readily prepared [(2,2‘-bipyridine)Cd(SC{O}Ph) 2 ] complex by simply refluxing in an aqueous solution. The as-prepared nanoparticles…
Tripodal cholamide 1 is a supergelator of aqueous fluids. A variety of physical techniques, including cryo-transmission electron microscopy (TEM), circular dichroism (CD), steady-state fluorescence, time-resolved fluorescence, and dynamic light-scattering, were employed to understand the structure and dynamics of the…
Hierarchical chiral structures made up of dendritic oligo(L- or D-glutamic acid) moieties of folic acid derivatives induce supramolecular chirality in the self-assembled columnar structures of the folic acids. These folic acids self-assemble through the intermolecular hydrogen bonds of the pterin rings to form disklik…
Spreading of a polymer drop on a solid substrate was monitored with molecular resolution. Three characteristic rates, i.e., the spreading rate of the precursor film ${D}_{\mathrm{s}\mathrm{p}\mathrm{r}\mathrm{e}\mathrm{a}\mathrm{d}}=(3.9\ifmmode\pm\else\textpm\fi{}0.2)\ifmmode\times\else\texttimes\fi{}{10}^{3}\text{ }…
The dielectric, ferroelectric and piezoelectric properties of barium titanate (BaTiO 3 )-based solid solution, (1- x )BaTiO 3 – x (Bi 1/2 K 1/2 )TiO 3 (0≤ x ≤1) (BT–BKT100 x ), a candidate lead-free piezoelectric ceramic, were studied using a starting material of fine BaTiO 3 powder. The Curie temperature, T c , of th…
Amphiphilic dendrimers with a custom-designed biaryl repeat unit have been synthesized. These dendrimers afford hydrophobic nanocontainers in polar solvents and hydrophilic nanocontainers in apolar solvents. These container properties were investigated using dye incorporation studies. The aggregation states of these d…
Using quantum mechanics we examined critical steps in the growth of single-walled carbon nanotubes (SWCN) for Ni, Co, Pt, Cu, Cr, Fe, Mo, Rh, Pd, and their combinations. This suggests a two-stage mechanism consisting of nucleation of nanotube growth (determining the number of SWCN) and growth with defect repair (deter…
We present a very efficient and accurate method to simulate scanning tunneling microscopy images and spectra from first-principles density functional calculations. The wave-functions of the tip and sample are calculated separately on the same footing, and propagated far from the surface using the vacuum Green's functi…
A general approach to the analysis of optical properties of photonic crystals based on multiple-quantum-well structures is developed. The effect of the polarization state and a non-perpendicular incidence of the electromagnetic wave is taken into account by introduction of an effective excitonic susceptibility and an…
We have designed, synthesized, and evaluated the physical properties of some high birefringence (Δ n ) isothiocyanato biphenyl-bistolane liquid crystals. These compounds exhibit Δ n ∼0.7–0.8 at room temperature and wavelength λ=633 nm. Laterally substituted short alkyl chains and fluorine atom eliminate smectic phase…
Er 3+ -doped ZnO nanocrystals with hexagonal wurtzite structure were prepared by addition of LiOH to Zn−O−Er precursors in ethanol. The well-known green hot band from the 2 H 11/2 → 4 I 15/2 transition in the 520 − 540 nm region and Stokes emissions were investigated. And the blue, green, and red upconversion emission…
Large-scale MoS2 and WS2 inorganic fullerene-like (IF) nanostructures (onionlike nanoparticles, nanotubes) and elegant three-dimensional nanoflowers (NF) have been selectively prepared through an atmospheric pressure chemical vapor deposition (APCVD) process with the reaction of chlorides and sulfur. The morphologies…
A method for engineering the surface chemistry and pore dimensions in porous Si films for the purpose of controlling the loading and release of a hydrophobic drug is described. Loading of the steroid dexamethasone is confirmed by Fourier transform infrared spectroscopy, and the release rates are characterized by obser…
We study the formation of nanostructures with alternating stripes composed of bulk-immiscible adsorbates during submonolayer heteroepitaxy. We evaluate the influence of two mechanisms considered in the literature: (i) strain relaxation by alternating arrangement of the adsorbate species, and (ii) kinetic segregation d…
We present a lattice formulation of a dynamic self-consistent field (DSCF) theory that is capable of resolving interfacial structure, dynamics and rheology in inhomogeneous, compressible melts and blends of unentangled homopolymer chains. The joint probability distribution of all the Kuhn segments in the fluid, intera…
In an earlier paper [K. K. Saha and A. Mookerjee, Phys. Rev. B 70 (2004) (in press) or, cond-mat/0403456] we had presented a formulation for the calculation of the configuration-averaged optical conductivity in random alloys. Our formulation is based on the augmented-space theorem introduced by one of us [A. Mookerjee…