Materials Literature
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We demonstrated a fast-switching liquid crystal display with bent polymer fibrils templated from a nematic host with a bend structure. The morphology of the bent polymer fibrils, formed by photopolymerizing a small amount of reactive monomer in a liquid crystal host, depends on monomer concentration, condition of phot…
We present new quasi-elastic neutron scattering experiments and simulation analysis for studying the hydration water dynamics of N -acetyl-leucine-methylamide (NALMA) solutions as a function of concentration and temperature. The experiments show non-Arrhenius translational dynamics over the temperature range of −3 to…
Abstract Water sorption was studied at 20 °C on films composed of different natural polymers. Three polysaccharides were investigated: chitosan, cellulose, and alginate. The major differences between these polymers, from a structural point of view, lay in the substitution of an OH group by an NH 2 function for chitosa…
We synthesized special-pair/electron-acceptor systems consisting of a complementary slipped cofacial dimer of imidazolyl-substituted zinc porphyrin, bearing pyromellitdiimide as the electron acceptor. In the case of the dimer, the first and second oxidation potentials were split into a total of four peaks in the diffe…
We report on a polarization-sensitive optical gain in a blue-emitting Si/SiO(2) nanocrystalline system having a high degree of emission polarization memory. This system can show a positive optical gain or optical loss depending on the polarization state of the pump and emitted light. Under optical gain conditions, the…
This paper presents results on the selective ablation of individual single-walled carbon nanotubes by use of intense picosecond laser pulses. Linearly polarized pulses ablate only those tubes that are oriented substantially along the polarization direction. When applied to random submonolayer networks of tubes on soli…
Germanium quantum dots embedded in a SiO 2 matrix fabricated by selective oxidation of SiGe-on-insulator structure were examined by high-resolution transmission electron microscopy, cathodoluminescence spectroscopy, and spectroscopic ellipsometry. The dot size and crystallite morphology were strongly dependent on ther…
Using generalized-gradient-corrected full-potential density-functional calculations we have studied the magneto-optical properties of double perovskites ${A}_{2}B{B}^{\ensuremath{'}}{\mathrm{O}}_{6}$, $A=\mathrm{Ca}$, Sr, and Ba; $B=\mathrm{Fe}$; and ${B}^{\ensuremath{'}}=\mathrm{Mo}$, W, and Re. ${\mathrm{Sr}}_{2}\ma…
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…