Materials Literature
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Motivated by the unusual soft mode anomalies in the relaxor ferroelectrics, we present a numerical study of vibrational excitations of a disordered lattice model with chemical order on the nano-scale. We find an Ioffe-Regel crossover in acoustic modes separating propagating low-frequency modes from the intermediate fr…
The low-temperature (T = 17.5 K) structure of titanium(III)-oxybromide, TiOBr, is reported as a two-fold superstructure of the crystal structure at room temperature. Weak superlattice reflections could be measured with synchrotron radiation x-rays, and they were analysed by structure refinements employing superspace t…
We present a tight-binding calculation of the influence of distorsion on the bulk electronic structure of the chalcopyrite CuInSe2. We calculate the ideal case and then the effect of the inclusion of the distortions. We analyze our results in detail and conclude from a comparison with other work that the distortions m…
A simple and rapid wet-chemical technique for the deposition of silver triangles on conventional glass substrates, which alleviates the need for lithography, has been developed. The technique is based on the seed-mediated cetyltrimethylammonium-bromide-directed growth of silver triangles on glass surfaces, where small…
Magnetoelectric (ME) CoFe2O4–Pb(Zr,Ti)O3 composite thin films have been prepared by a sol-gel process and spin-coating technique. X-ray diffraction and scanning electron microscopy reveal that there exists local aggregation or phase separation of the CoFe2O4 and Pb(Zr,Ti)O3 phases in the films. Vibrating sample magnet…
Equilibrium geometries, surface energies, and surfactant binding energies are calculated for selected bulk facets of wurtzite CdSe with a first-principles approach. Passivation of the surface Cd atoms with alkyl phosphonic acids or amines lowers the surface energy of all facets, except for the polar 000 facet. On the…
Chemical modification by SOCl2 of an entangled network of purified single-wall carbon nanotubes, also known as 'bucky paper', is reported to profoundly change the electrical and mechanical properties of this system. Four-probe measurements indicate a conductivity increase by up to a factor of 5 at room temperature and…
The melting temperature of ice I(h) for several commonly used models of water (SPC, SPC/E,TIP3P,TIP4P, TIP4P/Ew, and TIP5P) is obtained from computer simulations at p = 1 bar. Since the melting temperature of ice I(h) for the TIP4P model is now known [E. Sanz, C. Vega, J. L. F. Abascal, and L. G. MacDowell, Phys. Rev.…
Quantum dots (QDs) and magnetic nanoparticles (MPs) are of interest for biological imaging, drug targeting, and bioconjugation because of their unique optoelectronic and magnetic properties, respectively. To provide for water solubility and biocompatibility, QDs and MPs were encapsulated within a silica shell using a…
Insufficient reliability of hot gas filter materials is among the main obstacles to the replacement of traditional power generation processes with advanced, more efficient coal or biomass based routes. Knowledge of the effects of water vapour and thermal transients on microstructure and its relation to the mechanical…
We study the interwall interaction and relative motion of walls in carbon nanotubes using density functional theory. The interwall interaction energy surface as a function of relative rotation and sliding of walls is calculated for the (5,5)@(10,10) nanotube. The barriers to relative rotation and sliding are estimated…
The effects of different solvent mixtures and dispersants on non-aqueous suspensions of silicon carbide SiC were investigated by measuring settling rate, sediment height and viscosity. Based on these results, solvents, dispersants and dispersant concentrations were optimised to give the slurry with the lowest settling…
Multiwalled carbon nanotube (MWNT)∕BaTiO3 functional nanocomposites were fabricated via the spark plasma sintering technique. The resistivity of MWNT∕BaTiO3 nanocomposites was found higher than that of MWNT-free BaTiO3 ceramics. In addition, the temperature dependence of resistivity showed abnormal metallic conductanc…
Nanophase separation has been suggested to influence the biological performance of polyurethane. In a previous work, six different 4,4'-diphenylmethane diisocyanate (MDI)-based poly(carbonate urethane)s (PCUs) that exhibited various degrees of nanophase separation were synthesized and characterized. In the present wor…
The microrheology of viscoelastic fluids is obtained from rotational diffusion of optically anisotropic spherical colloidal probes, measured by depolarized dynamic light scattering. The storage and loss moduli obtained from the rotational mean squared displacement is in excellent agreement with those obtained from tra…
Abstract Summary: The crystal structure of the clathrate form of syndiotactic polystyrene containing ortho ‐dichlorobenzene has been determined, and compared with those of the other crystalline clathrate structures of s‐PS already known. This guest molecule, characterized by a quite different shape and volume from the…
Abstract Summary: Wide‐angle X‐ray diffraction (WAXD) was used to investigate the crystal transition of nylon‐12,12 under annealing and drawing. The triclinic α ‐form could be obtained by crystallizing from a melted state or by annealing the γ ‐form at high temperature (above 150 °C). The crystal structure of the α ‐f…
Hemocompatibility is an essential aspect of blood contacting polymers. Knowledge of the relationship between polymer structure and hemocompatibility is important in designing such polymers. In this work, the effect of swelling behavior and states of water on the hemocompatibility of poly(acrylonitrile-co-N-vinyl-2-pyr…
Abstract Summary: Modification of the type I polyhydroxyalkanoate synthase of Ralstonia eutropha (PhaC Re ) was performed through systematic in vitro evolution in order to obtain improved PhaC Re having an enhanced activity of poly(3‐hydroxybutyrate) (PHB) synthesis in recombinant Escherichia coli . For the first time…
Abstract Summary: Poly(methyl methacrylate)s (PMMAs) containing a terminal hydroxy group or multiple hydroxy groups as pendants were grafted to multiwalled carbon nanotubes (MWNTs) by esterification in toluene at 100 °C. The recovered polymer with a low level of MWNTs and the PMMA‐ g ‐MWNTs with up to 12 wt.‐% grafted…