Materials Literature
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Hall, resistivity, magnetization, and thermoelectric power measurements were performed on single crystals of the highly anisotropic layered metal LaSb2. A 100-fold linear magnetoresistance (MR) was observed in fields up to 45 T, with no indication of saturation. We show that the MR is associated with a magnetic-field-…
Following a previous work (Tissot, I.; Lefebvre, F.; Bourgeat-Lami, E. Macromolecules 2001, submitted for publication), polystyrene latex particles containing silanol groups have been synthesized in emulsion polymerization using 3-(trimethoxysilyl)propyl methacrylate (MPS) as a functional comonomer. The surface proper…
Abstract The properties of polyurethane (PU) nanocomposites with three different organoclays were compared in terms of their thermal stabilities, mechanical properties, morphologies, and gas permeabilities. Hexadecylamine–montmorillonite, dodecyltrimethyl ammonium–montmorillonite, and Cloisite 25A were used as organoc…
A novel nanocomposite containing polyethylene and polyhedral oligomeric silsesquioxane (POSS) nanoparticles has been characterized using wide-angle X-ray scattering (WAXS). In copolymers formed between ethylene and POSS containing macromonomers, the POSS units, attached as pendant groups off the polyethylene backbones…
We employ density functional and quantum Monte Carlo calculations to show that significant changes occur in the gap of fully hydrogenated nanoclusters when the surface contains passivants other than hydrogen, in particular atomic oxygen. In the case of oxygen, the gap reduction computed as a function of the nanocluste…
Polyelectrolyte multilayers of poly(acrylic acid) (PAA) and polyacrylamide (PAAm) were prepared via hydrogen-bonding interactions. These multilayers as assembled were stable at low pH but dissolved quickly in neutral pH water. We developed methods for stabilizing these multilayers to high pH through cross-linking by h…
Abstract We successfully synthesized an anionic water‐borne polyurethane (PU) capable of reacting with a reactive dye to form a covalent bond with the dye molecule. The anionic water‐borne PU was synthesized and grafted with the reactive dye to form a dyed PU. First, the PU prepolymer was synthesized from 4,4′‐methyle…
Abstract Generalized two‐dimensional (2D) Fourier transform infrared correlation spectroscopy was used to investigate the effect of the comonomer compositions on the crystallization behavior of two types of biosynthesized random copolymers, poly(hydroxybutyrate‐ co ‐hydroxyhexanoate) and poly(hydroxybutyrate‐ co ‐hydr…
Novel benzofuranonaphthoquinol-type clathrate hosts, which exhibit fluorescence enhancement behaviour with a blue shift of the emission maximum upon formation of clathrates with amines, have been developed. The clathrate compounds are formed not only by cocrystallization from amine solutions but also by solid (host)–g…
In order to investigate the paramagnetic ground state of the colossal magnetoresistance (CMR) ${\mathrm{Sm}}_{0.55}{\mathrm{Sr}}_{0.45}{\mathrm{MnO}}_{3}$ compound we have used a wide set of techniques: magnetoresistance, magnetization, high-resolution neutron diffraction, small-angle neutron diffraction, and muon spi…
Abstract Solid‐state polymerization (SSP) of poly(ethylene terephthalate) (PET) is characterized by two distinct features. First, there exists an ultimate or limiting intrinsic viscosity ( IV ). Second, the SSP rate varies with the prepolymer IV. Although there are several existing empirical rate equations and numerou…
Recently, the thermal conductivity in disordered chains has attracted a lot of attention, including the discussion of the disorder anharmonic and harmonic chains. A natural problem concerns the higher-dimensional disordered lattice system. This paper gives a 2D harmonic lattice model with missing bond defects. When th…
The microstructure of the $\ensuremath{\alpha}\ensuremath{-}{\mathrm{Al}}_{2}{\mathrm{O}}_{3}(112\ifmmode\bar\else\textasciimacron\fi{}0)$ surface has been investigated by means of He-atom scattering (HAS), low energy electron diffraction (LEED), atomic force microscopy, and x-ray photoelectron spectroscopy. Heating t…
Abstract Blending colored fibers consists of combing fibers together many times in order to obtain a homogeneous color by intimate mixing. If a reflectance curve is to be reproduced, the required proportions of colored fibers are evaluated by trial and error. Two formulas have been introduced to model such a means of…
Abstract Miscibility, melting, and crystallization behaviors of solution‐blended poly(trimethylene terephthalate) (PTT)/poly(ether imide) (PEI) blends have been investigated using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and polarized light microscopy (PLM). These blends show a single…
Zinc-blende (\ensuremath{\alpha}-) and NiAs-type (\ensuremath{\beta}-) MnAs are investigated with a combined first-principles linearized argumented plane wave and ${\mathrm{DMol}}^{3}$ study within both the local density approximation (LDA) and the generalized gradient approximation (GGA). First-principles calculation…
Abstract Semi‐interpenetrating polymer networks (SIPNs) consisting of polycaprolactone (PCL) and poly(ethyleneglycol) (PEG) macromer was prepared to improve tensile property in developing biodegradable sutures. When the PEG macromer formed SIPNs with PCL, biodegradability, mechanical strength, and hydrophilicity were…
The histidine biosynthetic pathway is an ancient one found in bacteria, archaebacteria, fungi, and plants that converts 5-phosphoribosyl 1-pyrophosphate to l-histidine in 10 enzymatic reactions. This pathway provided a paradigm for the operon, transcriptional regulation of gene expression, and feedback inhibition of a…
The magnetic circular dichroism (MCD) of core-level absorption [x-ray absorption spectroscopy (XAS)] spectra in the soft x-ray region has been measured for the ferromagnetic Heusler alloys ${\mathrm{Co}}_{2}\mathrm{TiSn},$ ${\mathrm{Co}}_{2}\mathrm{ZrSn},$ and ${\mathrm{Co}}_{2}\mathrm{NbSn}.$ The many-peak structures…
Abstract Bacterial polyesters have shown potential as biodegradable plastics. Microorganisms capable of producing these polyesters from cheaper carbon sources and methods for their efficient recovery are widely studied worldwide. Methylobacterium sp V49, an environmental isolate, was cultivated on a mineral salts medi…