Materials Literature
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Static and dynamical properties of carbon nanotubes under uniaxial tension have been investigated via quantum and classical simulations. In strained nanotubes at high temperatures we observe the spontaneous formation of double pentagon-heptagon defect pairs. Tubes containing these defects are energetically preferred t…
Using nonresonant bond-polarization theory, the Raman intensity of a single-wall carbon nanotube is calculated as a function of the polarization of light and the chirality of the carbon nanotube. The force-constant tensor for calculating phonon dispersion relations in the nanotubes is scaled from those for two-dimensi…
A fast-flow reactor quadrupole mass spectrometer coupled with a laser vaporization source is used to study the gas-phase reactions of nickel oxide cluster anions (Ni x O y ) - with nitric oxide (NO). The results show that nitrogen dioxide (NO 2 ) is formed on the nickel oxide clusters and that this formation leads to…
The efficiency and wavelength sensitivity of photodegradation in polystyrene (PSt) in the presence of a flame retardant were studied. The effect of the concentration of a flame retardant on the degradation of PSt was also investigated. Four kinds of flame retardant containing bromine atoms in the molecule and having t…
This article was focused on the effects of the NCO/OH molar ratio and 2,2-bis(hydroxyl methyl) propionic acid (DMPA) content during prepolymerization on the physical properties of synthesized waterborne polyurethane (WBPU) by using the polycaprolactone–poly(ethyl glycol)–polycaprolactone triblock copolydiol (PCL–PEG–P…
Blends of conductive polymers with classical ones can exhibit good mechanical properties and good electrical conductivity and deserve great attention for application in electronic industrial technology. Conductive polyaniline solutions have been chemically prepared using bis(2-ethyl hexyl)hydrogen phosphate (DiOHP) as…
The ground, excited, and ionized states of free-base porphin (FBP) are reinvestigated by the SAC (symmetry-adapted cluster)/SAC-CI (configuration interaction) method. In particular, the Rydberg excited states, the valence−Rydberg mixing, and the effect of polarization d-functions are studied. The lowest Rydberg excite…
This study compared the performance of eight commercial starch and expanded polystyrene (EPS)-based loose-fill foam products. Density of starch-based foams is higher, by a factor of two to three times, than either EPS-based ones. Compressive stress of most starch-based foams did not differ significantly from 0.0893 MP…
We discuss some problems of lattice tiling via Harmonic Analysis methods. We consider lattice tilings of ${\bf R}^d$ by the unit cube in relation to the Minkowski Conjecture (now a theorem of Hajós) and give a new equivalent form of Hajós's theorem. We also consider "notched cubes" (a cube from which a rectangle has b…
Conductive polyaniline solutions were chemically prepared using bis (2-ethylhexyl) hydrogen phosphate (DiOHP) as the dopant chemical species. The codissolution method leads to conductive polyaniline–polystyrene (PANI–PSt) composites with good mechanical properties. The electronic structure of both conducting PANI film…
Reaction of nanocrystalline (“porous”) silicon with phenyllithium and lithium phenylacetylide results in functionalization of the silicon surface with phenyl and phenylacetylene moieties, respectively. The reaction proceeds by addition of the aryllithium reagent across a surface Si−Si bond, resulting in a Si−aryl bond…
The evolution of the dispersed surface molybdate phase on high-surface-area magnesium oxide is studied as a function of weight loading of MoO 3 and calcination temperature using in situ Mo L 3 -edge X-ray absorption near edge spectroscopy, in situ laser Raman spectroscopy, and thermogravimetry−mass spectroscopy. Under…
Mn4/(AE)2 complexes, AE = Ca, 1 or Ba, 2, display MnIII3MnII valence-trapped states and Jahn−Teller compressed MnIII ions, consistent with the S0 (or S-2) oxidation level of PSII. Ba2+ and Ca2+ ligate Mn-bonded carboxylate oxygens either directly or via H2O molecules, respectively. The (O−H−O)3- ligand, symmetric, μ4,…
The synthesis and the phase behavior of a homologous series of polymers of 4,4‘-[1,12-dodecanediylbis(oxy)]bis(benzoic acid) with bis[ N -[[2,4-dihydroxyphenyl]methylene]alkylamino]nickel(II), -palladium(II) and -oxovanadium(II) are reported. Calorimetric and X-ray diffraction data and dynamic viscosity measurements a…
Poly(3-hydroxyoctanoate- co -3-hydroxy-10-undecenoate)s (PHOUs) with controlled amounts of unsaturated side chains were produced by Pseudomonas oleovorans from various mixtures of 10-undecenoic acid and octanoic acid. Epoxidation of the unsaturated side chains in PHOU, by reacting the polymer with m -chloroperbenzoic…
The self-assembling technique was employed for modification of a citrate-reduced silver hydrosol with mercaptoethanol (ME). The results of investigation of the structure and properties of both the self-assembled monolayers (SAMs) of ME and the modified hydrosol as a substrate for surface-enhanced Raman scattering (SER…
Nonlinear optical properties in the fullerene C$_{60}$ and the extracted higher fullerenes -- C$_{70}$, C$_{76}$, C$_{78}$, and C$_{84}$ -- are theoretically investigated by using the exciton formalism and the sum-over-states method. We find that off-resonant third order susceptibilities of higher fullerenes are a few…
Pulsed plasma polymerization is used to produce aromatic thin films from inductively coupled rf plasmas with benzene, 1,2,4-trifluorobenzene, and hexafluorobenzene as monomers. The effects of aromatic monomer fluorination and duty cycle variation on the resulting films' properties are examined. The surface and bulk pr…
Colloidal silver has been formed either by irradiation with 253.7 nm light or by chemical reduction of AgClO 4 in the presence of protective agents such as poly(vinylpyrrolidone), carboxy methyl cellulose, and gelatin. The particles were characterized by their absorption maximum and transmission electron micrographs.…
Poly(butylene terephthalate) (PBT) was depolymerized in refluxing o -dichlorobenzene using stannoxane catalysts to produce good yields of cyclic oligomers. We have studied how the ring size distribution varies as a function of the starting concentration of monomer units. Over a concentration range of 0.05 to 0.2 M, th…