Materials Literature
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The structural changes and phase transition of kaolinite during thermal treatment were investigated by thermogravimetric analysis, differential thermal analysis, infrared spectroscopy, X‐ray diffraction (XRD) and solid‐state 29 Si magic angle spinning nuclear magnetic resonance in this paper. It was found that kaolini…
Broadband dielectric measurements at very large hydrostatic pressures (up to 1.8 GPa) are used to investigate the effect of molecular structure on the dynamical properties of supercooled di- n -butyl phthalate (DBP) and its isomer, diisobutyl phthalate (DiBP). At atmospheric pressure, both the shape of the α-relaxatio…
Abstract Properties of the point‐bonded nonwoven fabrics are dependent on the bonding conditions, in addition to those of the polymer/fiber. Thermally bonded carded webs were produced and characterized to investigate the role of bond area, bond size, and bonding temperature on the structure and properties of point‐bon…
Abstract A series of polymer–clay nanocomposite (PCN) materials that consist of organosoluble polyimide and layered montmorillonite clay were prepared by the solution dispersion technique. The organosoluble polyimide containing non‐coplanar moiety in diamine monomer and flexible bridging linkages in dianhydride monome…
The formation of endothermic carbides on Fe and Ni is studied using X-ray photoelectron spectroscopy (XPS) by deposition of carbon films from the vapor phase and subsequent annealing steps. The reaction between carbon and metal substrates is measured by shifts in the C 1s photoelectron peaks. By comparison with two el…
The thermoelectric properties of Y-doped polycrystalline SrTiO 3 (Sr 1- x Y x TiO 3 ) are measured from 10 K to 900 K. The Y component is doped up to the solubility limit of Sr 1- x Y x TiO 3 , x =0.1. The Y-doped polycrystalline samples show a low resistivity, ∼1 ×10 -5 Ω·m and a large absolute value of the Seebeck c…
The surface recombination probability of oxygen atoms as a function of wall temperature is studied by using a double pulse discharge technique. The main discharge pulse dissociates molecular oxygen and the second pulse, shorter than the main one, excites atoms during the stationary afterglow. The recombination probabi…
First-principles quantum-mechanical techniques, based on density functional theory (B3LYP level) were employed to study the electronic structure of ordered and deformed asymmetric models for ${\mathrm{Ba}}_{0.5}{\mathrm{Sr}}_{0.5}{\mathrm{TiO}}_{3}.$ Electronic properties are analyzed and the relevance of the present…
Photonic control of photoinduced electron transfer has been demonstrated in a dimethyldihydropyrene (DHP) porphyrin (P) fullerene (C(60)) molecular triad. In the DHP-P-C(60) form of the triad, excitation of the porphyrin moiety is followed by photoinduced electron transfer to give a DHP-P(*)(+)-C(60)(*)(-) charge-sepa…
By measuring the anti-Stokes (AS) and Stokes (S) Raman spectra on the same isolated single-wall carbon nanotube (SWNT), we here determine the electronic transition energies ${E}_{\mathrm{ii}}$ experimentally ${(E}_{\mathrm{ii}}^{\mathrm{exp}}),$ and then we compare these ${E}_{\mathrm{ii}}^{\mathrm{exp}}$ with the ${E…
Multiwall carbon nanotubes (MWNTs) were synthesized in supercritical toluene at 600 degrees C and approximately 12.4 MPa using ferrocene, Fe, or FePt nanocrystals as growth catalysts. Toluene serves as both the carbon source for nanotube formation and the solvent. In contrast to vapor-phase synthetic routes, the super…
Abstract The filler action of dodecylamine (12C) intercalated montmorillonite (MNT) referred to as organomodified montmorillonite (12C‐MNT) up to 4 wt % on natural rubber (NR) and styrene butadiene rubber (SBR) was studied and findings were compared with respect to the unmodified Na‐MNT. X‐ray analysis was used to cal…
We present results from detailed atomistic simulations concerning the structural, conformational, dynamic, and barrier properties of the amorphous (glassy and melt) phases of two polyisomers, PET [poly(ethylene terephthalate)] and PEI [poly(ethylene isophthalate)]. First, well-relaxed atomistic configurations of the t…
Copper-containing cerium oxide materials are shown in this work to be suitable for the high-temperature water−gas shift (WGS) reaction integrated with hydrogen separation in a membrane reactor to generate pure hydrogen. Copper−ceria is a stable high-temperature shift catalyst, unlike iron−chrome catalysts that deactiv…
We have studied atomic structures of a-sexithienyl (6T) films grown on Cu(110) by near-edge x-ray absorption fine structure (NEXAFS). A one-dimensional (1D) ordered structure of 6T with its molecular long axis parallel to the Cu[001] direction could be fabricated by deposition at 300 K and subsequent annealing at 360…
With the eventual aim of describing flowing elasto-plastic materials, we focus on the elementary brick of such a flow, a plastic event, and compute the long-range perturbation it elastically induces in a medium submitted to a global shear strain. We characterize the effect of a nearby wall on this perturbation, and qu…
We report on first-principles calculations of multilayers of zinc-blende half-metallic ferromagnets CrAs and CrSb with III-V and II-VI semiconductors, in the [001] orientation. We examine the ideal and tetragonalised structures, as well as the case of an intermixed interface. We find that, as a rule, half-metallicity…
The build-up of exciton populations in resonantly laser excited semiconductors is studied microscopically. For excitation at the $2s$-exciton resonance, it is shown that polarization with a strict $s$-type radial symmetry can be efficiently converted into an incoherent $p$-type population. As a consequence, inversion…
We investigate the motion of a hard cylinder rolling down a soft inclined plane. The cylinder is subjected to a viscous drag force and stochastic fluctuations due to the surrounding medium. In a wide range of parameters we observe bistability of the rolling velocity. In dependence on the parameters, increasing noise l…
If magnetic semiconductors are ever to find wide application in real spintronic devices, their magnetic and electronic properties will require tailoring in much the same way that band gaps are engineered in conventional semiconductors. Unfortunately, no systematic understanding yet exists of how, or even whether, prop…