Materials Literature
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Abstract The influence of the crystalline areas observed in poly(vinyl chloride) (PVC) the mechanical and thermal properties of PVC plastisols was studied. Several industrial‐degree PVC resins were used to obtain a broad range of molecular weights and processing conditions for PVC plastisols. The gelation process was…
Abstract The thermal behavior and properties of immiscible blends of polystyrene (PS) and poly(methyl methacrylate) (PMMA) with and without PS‐ b ‐PMMA diblock copolymer at different melt blending times were investigated by use of a differential scanning calorimeter. The weight fraction of PS in the blends ranged from…
Abstract The dynamic vulcanization of reclaimed‐tire rubber (RTR) and homopolypropylene (PP) was performed by melt‐mixing using either a sulfur crosslinking agent, maleic anhydride (MA), dicumyl peroxide (DCP), or the combination of MA and DCP, in two consecutive machines, first a two‐roll mill and then a counterrotat…
Abstract The main benefits of incorporating wood fibers (WF) in plastics are the increased stiffness and lowered cost of the resulting composites. However, these improvements are usually accompanied by a reduction in the ductility and impact resistance. These shortcomings can be removed by effectively foaming and inco…
An activated carbon template substitution reaction has been used to synthesize activated boron nitride (BN). The resulting material is characterized by scanning electron microscopy, high-resolution transmission electron microscopy, electron energy loss spectroscopy, and surface area analysis. The activated BN microstr…
A large bis-urea macrocycle was synthesized and assembled into columnar nanotubes containing a sizable cavity. This purely organic nanotube is held together primarily by hydrogen bonding and yet shows remarkable thermal stability up to 180 degrees C in the presence and absence of acetic acid guest. This enables the na…
Identification of charge transfer and trapping sites on semiconducting oxide surfaces is of fundamental importance in furthering the field of heterogeneous photocatalysts. Using scanning tunneling microscopy, electron energy loss spectroscopy, and photodesorption, we observed both electron trapping and hole transfer e…
We have observed the formation of ripples in a number of thin metal films, e.g. Au, Pt, Ag, Cu and Co under Ar^{+} ion beam sputtering at grazing incidence. The structures are found to be quite stable under ambient conditions. The results show that the ripple formation in polycrystalline metallic films relies on the e…
Using results of the band structure calculations in the local-spin-density approximation we demonstrate how the crystal distortions affect the magnetic structure of orthorhombically distorted perovskites leading to a non-collinear spin arrangement. Our results suggest that the non-collinearity of the spin magnetic mom…
It is argued that the non-collinear orbital magnetism accompanying the orthorhombic distortion is an important ingredient which should be taken into consideration for making promising materials with the best magneto-optical characteristics on the basis of SrRuO$_3$.
We study using first-principles calculations the energetics, structural and electronic properties of nitrogen incorporation in SiO2. We consider NO, NH, N2 and atomic N as the nitriding species interacting with a Si-Si bond of an otherwise perfect SiO2 network in order to simulate the nitrogen incorporation near Si/Si…
Observations are reported in isothermal torsional oscillation tests on melts of isotactic polypropylene (iPP) and low-density polyethylene (LDPE) in the intervals of temperature between 190 and 250C (iPP) and between 120 and 190C (LDPE). With reference to the concept of transient networks, constitutive equations are d…
Pulsed ArF laser annealing in air and in hydrogen atmosphere improves the optical properties of ZnO nanostructured films. Independently on the ambient atmosphere, laser annealing produces two major effects on the photoluminescence (PL) spectra: first, the efficiency of the exciton PL increases due to decrease of the n…
We present the results of experiments on synthesis of ZnO nanoclusters by reactive pulsed laser deposition (PLD). The nanoclusters were formed and crystallized in the gas phase and deposited on SiO2 substrates. The nanostructured films were characterized by conventional photoluminescence (PL). The PL spectra consist o…
Gold nanowires were synthesized at 150 K by electron beam thinning of a gold thin foil in an UHV electron microscope. The gold nanowires were found to have a helical multishell structure (HMS). One particular nanowire, which was thinner than the 7-1 HMS nanowire, was found to have a tubular structure. The gold single…
We show that it is possible to have hysteretic behavior for magnets that does not form simple closed loops in steady state, but cycles multiple times before returning to its initial state. We show this by studying the low temperature dynamics of the 3D Edwards-Anderson spin glass. The specific multiple varies from sys…
Using a phenomenological model we study the first- and second-order phase transitions in the ${A}_{1\ensuremath{-}x}{M}_{x}{\mathrm{MnO}}_{3}$ system, with $x\ensuremath{\approx}1/3.$ The free energy in the vicinity of transition point is investigated. The continuous and discontinuous behavior of the order parameter i…
Analysis of high-resolution powder neutron diffraction data for $\mathrm{Pb}[({\mathrm{Mg}}_{1/3}{\mathrm{Nb}}_{2/3}{)}_{0.71}{\mathrm{Ti}}_{0.29}]{\mathrm{O}}_{3}$ is presented to show unambiguously that its structure is not rhombohedral but monoclinic of ${M}_{B}$ type. Presence of this phase in between the rhombohe…
We analyze the structural distortions associated with positively and negatively charged states produced upon doping poly (p-phenylene vinylene) (PPV). Vibrational frequencies associated with excitations in these charged states are analyzed on the basis of the valence force field and model-compound approaches. In situ…
The high cost of a currently available selective catalytic reduction (SCR) process is driving R&D efforts toward finding alternative technologies to remediate NO emissions from utility boilers. A hybrid plasma−catalyst (P−C) system is investigated for NO x removal. The plasma (dielectric barrier discharge) and SCR tec…