Materials Literature
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Abstract Template‐free, self‐assembled polyaniline (PANI) nanotubes were prepared in a solution of poly(methyl vinyl ether‐ alt ‐maleic acid) (PMVEA) by oxidative polymerization using ammonium persulfate as the oxidant. The weight ratio of the polymeric acid to aniline in the solution had a significant effect on the s…
Nephila clavipes dragline silk microstructure has been investigated by scanning transmission X-ray microscopy (STXM), a technique that allows quantitative mapping of the level of orientation of the peptide groups at high spatial resolution (<50 nm). Maps of the orientation parameter P2 have been derived for spider sil…
[structure: see text] A 15 625-membered peptide dendrimer combinatorial library was acylated with an alpha-C-fucosyl residue at its four N-termini and screened for binding to fucose-specific lectins. Dendrimer FD2 (Fuc-alpha-CH2CO-Lys-Pro-Leu)4(Lys-Phe-Lys-Ile)2Lys-His-Ile-NH2 was identified as a potent ligand against…
A thermal phase transition has been resolved in gold nanoparticles supported on a surface. By use of asynchronous optical sampling with coupled femtosecond oscillators, the Lamb vibrational modes could be resolved as a function of annealing temperature. At a temperature of 104 degrees C the damping rate and phase chan…
The crystal structure of ${\mathrm{Ni}}_{2+x}{\mathrm{Mn}}_{1\ensuremath{-}x}\mathrm{Ga}$ has been studied as a function of composition $(x)$ by powder x-ray diffraction. For ${\mathrm{Ni}}_{2.24}{\mathrm{Mn}}_{0.75}\mathrm{Ga}$, where one-fourth of the Mn atoms are replaced by Ni, the experimentally determined lattic…
The first structure-reactivity relationship for electron-transfer reactions of single walled carbon nanotubes (SWNTs) has been derived and experimentally validated using 4-hydroxybenzene diazonium as a model electron acceptor. The model describes steady-state reaction data using an adsorption-controlled scheme, and el…
We report a study of aggregation behavior of polybenzimidazole (PBI) in polar aprotic solvents such as dimethylacetamide (DMAc). The photophysical studies of the PBI solution at various concentrations show concentration quenching and reveal that aggregated structures are formed when the polymer concentration is increa…
When long polymers such as DNA are in a highly concentrated state they may become entangled, leading to restricted self-diffusion. Here, we investigate the effect of molecular topology on diffusion in concentrated DNA solutions and find surprisingly large effects, even with molecules of modest length and concentration…
Electric field-induced phase transitions were investigated in (111), (110), and (100) thin platelets of relaxor ferroelectric $\mathrm{Pb}({\mathrm{Mg}}_{1∕3}{\mathrm{Nb}}_{2∕3}){\mathrm{O}}_{3}$ single crystals with electric fields applied along the $⟨111⟩$, $⟨110⟩$, and $⟨100⟩$ directions, respectively. Temperature…
Nanosized γ-MnOOH (manganite) has been synthesized by a new route via the reduction of KMnO 4 with sucrose and MnSO 4 in acidic medium under refluxing conditions for 4 and 6 h. Characterization of these manganite materials using XRD, FESEM, TEM, TGA, and IR were carried out. The obtained manganite samples using the ne…
Cathodoluminescence imaging and spectroscopy experiments on a single bamboo-like boron nitride nanotube are reported. Imaging experiments show that the luminescence is located all along the nanotube. Spectroscopy experiments point out the important role of dimensionality in this one dimensional object.
The translational and rotational diffusion of a series of gold nanorods with low aspect ratios was investigated by dynamic light scattering (DLS). It is shown that the translational and rotational diffusion coefficients can be determined because the particle shape causes an anisotropy of the polarizability. This gives…
We report a highly effective growth of vertically aligned ZnO one-dimensional (1D) nanostructures on conducting alloy substrate (Fe−Co−Ni) in mild solutions ( T ≤ 70 °C) in the absence of any seeds, catalysts, and surfactants. The growth conditions such as NH 3 ·H 2 O concentration, temperature, and nature of the subs…
The effect of a weak uniform magnetic field on the electronic structure of slightly deformed fullerene molecules is studied within the continuum field-theory model. It is shown that fine structure of the electronic energy spectrum is very sensitive to the orientation of the magnetic field. In particular, we found that…
The van der Waals dispersion coefficients of a set of polycyclic aromatic hydrocarbons, ranging in size from the single-cycle benzene to circumovalene (C66H20), are calculated with a real-time propagation approach to time-dependent density functional theory (TDDFT). In the non-retarded regime, the Casimir-Polder integ…
Elastically anisotropic, physically based, length-scale- and rate-dependent crystal plasticity finite element investigations of a model hcp polycrystal are presented and a systematic study was carried out on the effects of combinations of crystallographic orientations on local, grain-level stresses and accumulated sli…
We demonstrate theoretically that quantum dots in bilayers of graphene can be realized. A position-dependent doping breaks the equivalence between the upper and lower layer and lifts the degeneracy of the positive and negative momentum states of the dot. Numerical results show the simultaneous presence of electron and…
We present a first-principles study of the atomic hydrogen adsorption onto the Be(10\={1}0) thin film. There are two types of Be(10\={1}0) surfaces according to the interlayer spacing between the surface and its nearest-neighbor layer. We show that the H adsorption features on these two kinds of surfaces are remarkabl…
The physics of sliding nanofriction at high temperature near the substrate melting point $\Tmelt$ is so far unexplored. We conducted simulations of hard tips sliding on a prototype non-melting surface, NaCl(100), revealing in this regime two distinct and opposite phenomena for plowing and for grazing friction. We foun…
We have carried out first-principles calculations of Be(0001) thin films to study the oscillatory quantum size effects exhibited in the surface energy, work function, and binding energy of the atomic hydrogen monolayer adsorption. The prominent enhancement of the surface density of states at the Fermi level makes Be(0…