Materials Literature
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The semicrystalline morphology of poly(3-hydroxy butyrate) (PHB)/poly(vinyl acetate) (PVAc) blends at four crystallization temperatures ( T c = 70, 90, 110, and 125 °C) was probed by small-angle X-ray scattering (SAXS). Morphological parameters including the crystal thickness ( l c ) and the amorphous layer thickness…
The synthesis of fourth-generation poly(amido−amine) (PAMAM) dendrimers having terminal groups partially or fully functionalized with thiol groups is described. These thiolated dendrimers form stable monolayers on planar Au substrates. X-ray photoelectron spectroscopy studies reveal that most of the thiol groups on de…
In this paper we show that hyperbranched polymers can be used as a host matrix for electrostatic entrapment of enzymes. Specifically, amine-functionalized glucose oxidase (GOx+) and horseradish peroxidase, as well as poly(amidoamine) dendrimer-modified horseradish peroxidase, reversibly sorb into polyanionic, hyperbra…
We propose that the low temperature discrepancy between simple d-wave models of the microwave conductivity and existing experiments on single crystals of YBCO can be resolved by including the scattering of quasiparticles from "holes" of the order parameter at impurity sites. Within a framework proposed previously, we…
To clarify the mechanism of cross-interfacial molecular transport and the role of subcritical cluster population in determining the kinetics of crystal nucleation, cluster dynamics calculations based on viscosity-governed rate coefficients are confronted with experiments on crystal nucleation in six stoichiometric oxi…
The synthesis of 2-phenylthieno[3,4-b]thiophene was carried out in two steps from 3,4-dibromothiophene and phenylacetylene. Electropolymerization of this monomer affords a novel low band gap (Egap) polymer that was characterized by cyclic voltammetry and electrochemistry. An Egap of ca. 0.85 eV was observed, which is…
Poly(vinyl alcohol) (PVA) was cyanoethylated by reaction with acrylonitrile in the presence of sodium hydroxide and quaternary ammonium halide. Quaternary ammonium halide, acting as a phase transfer catalyst, increases the degree of substitution (DS) of PVA. The DS also increased with increasing acrylonitrile concentr…
We have explored the use of hydroperoxide decomposing species for inhibiting oxidation in jet fuel. We find that hydroperoxide decomposing species, such as alkyl sulfides, do not slow or delay oxidation in hydrocarbon solvents at 140 °C. However, when phenolic species are also present, such as those naturally occurrin…
We present the results of a neutron reflectometry study of the kinetics of penetration of a grafted polymer layer into a permanently cross-linked, chemically identical network. The polymer used was polystyrene. Initially the grafted chains are completely excluded from the network, and the interface between them is sha…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTCore−Shell Cylinders and Core−Shell Gyroid Morphologies via Blending of Lamellar ABC Triblock and BC Diblock Copolymers†Thorsten Goldacker and Volker AbetzView Author Information Makromolekulare Chemie II, Universität Bayreuth, D-95…
Three different types of isosbestic points observed for liquid water are dealt with in this paper—temperature induced Raman, temperature induced structural, and pressure induced structural isosbestic points. These isosbestic points leave no doubt as to the precise two-state outer-neighbor mixture model description of…
Fine palladium (Pd) particles, which have a diameter of 4−5 nm and are coordinated with the poly(2-vinylpyridine) homopolymer (P2VP) or poly(2-vinylpyridine)- block -polyisoprene diblock copolymer (P2VP- b -PI), were prepared by the reduction of palladium acetylacetonate (Pd II (acac) 2 ) with 1-propanol in the dilute…
A simple route to synthesize polyhedral silsesquioxanes, (RSiO 1.5 ) n, by the hydrolytic condensation of modified aminosilanes, is reported. The starting material was N -(β-aminoethyl)-γ-aminopropyltrimethoxysilane, a trifunctional aminosilane. It was reacted with a stoichiometric amount of phenylglycidyl ether in se…
Finite-field many-body perturbation theory and coupled cluster calculations are reported for the static second dipole hyperpolarizability γαβγδ of trans-butadiene. A very large basis set of [9s6p4d1f/6s3p1d] size (336 contracted Gaussian-type functions) should lead to self-consistent field (SCF) values of near-Hartree…
The synthesis of mesoporous silica materials has been achieved with d -glucose as a nonsurfactant pore-forming agent in the sol−gel reactions of tetraethyl orthosilicate under basic or near neutral (pH 6) conditions. Regardless of the pH values of the medium, transparent and monolithic glucose-containing silica gels c…
Numerical studies of amorphous silicon show that the lowest 4% of vibrational modes are plane-wave like ("propagons") and the highest 3% of modes are localized ("locons"). The rest are neither plane-wave like nor localized. We call them "diffusons." Since diffusons are by far the most numerous, we try to characterize…
A sharp distinction between magnetoresistance (MR) behavior for the magnetic fields applied perpendicular (H_{perp}) and parallel (H_{par}) to the film plane is found in colossal-magnetoresistance film La_{1-x}Ca_{x}MnO_{3} (x \approx 3). At increasing of H_{perp} the MR is first negative (at H_{perp} < 4 kOe), then p…
The effect of disorder on the perpendicular magnetoresistance of magnetic multilayers is investigated theoretically. Various kinds of disorder are considered: (i) interface substitutional disorder and (ii) bulk disorder in the various layers and in the leads. The calculations are based upon the non-equilibrium Green's…
Poly(acrylic acid) (PAAc) and poly(vinyl chloride) (PVC) were treated with an argon plasma to create unsaturated bonds at the surface. By use of X-ray photoelectron spectroscopy and Fourier transform infrared measurements, it was shown that the pendant groups of these polymers are removed by the argon plasma treatment…
Poly(vinylpyrrolidone) (PVP)-stabilized Pt clusters (1.4 nm average particle size) were embedded in an amorphous microporous titania−silica mixed oxide (AMM- Me Si 30 Ti) by means of a modified sol−gel procedure. The Pt particles were shown by transmission electron microscopy to retain their approximate original avera…