Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Successive passes through an extruder can modify the melt morphology of low-density polyethylene (LDPE) by applying a shearing process. The major effects of shear modification are to decrease the elastic properties, as evidenced by the decrease in extrudate swell at the exit of a capillary and in melt viscosity at a l…
In this paper, we present, for the first time, the magnetic properties of Cd 1 - y Mn y S nanocrystals of average size (4 nm) at various compositions, y . We demonstrate that the Mn−Mn interactions are markedly enhanced compared to the bulk material. As in the bulk phase, the photoluminescence and the EPR hyperfine st…
Using low-angle laser light-scattering (LALLS) and multiangle laser light-scattering (MALLS) techniques, absolute molar mass averages were determined for a wide variety of polymers in the Methocel™ product line produced by The Dow Chemical Company. These data were correlated to GPC molar mass averages obtained from co…
Size distribution information was used to monitor time-dependent agglomeration in aqueous solutions of a high molecular mass polyacrylamide. Although the individual polymer molecules had diameters in the order of 0.4 μm, a high number of agglomerates were seen that may contain four to six polymer chains. As the soluti…
Two sets of organotin compounds, that is, one having dibutyl and the other dioctyl groups each with a varying length of a carboxyl group attached to a tin atom, were studied as catalysts for the polycondensation of room temperature vulcanization of hydroxyfunctional polydimethylsiloxane (HOPDMS). The experiments were…
The crystal structure and the morphology of poly(ethylene oxide) (PEO)−2-methyl resorcinol (MRES) supramolecular complexes are investigated by differential scanning calorimetry and wide-angle and small-angle X-ray scattering. Depending on the MRES content, two molecular complexes with different stoichiometries are obs…
Polypyrrole (PPY) films with a thickness of 3–4 μm were obtained by chemical oxidation of pyrrole (PY) at the interface of chloroform and water with an oxidant (NH4)2S2O8. The films were compact and could be removed with a solid plate. The quality and compositions of these films varied with the molar ratios of the mon…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOptoelectronic Properties and Memories Based on Organic Single-Crystal Thin FilmsChong-yang Liu and Allen J. BardView Author Information Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712 Cite this: Acc. Chem. Res. 1999, 32, 3, 2…
Agrowastes and woodflour are a potential and attractive alternative of cheap reinforcement for brittle polymeric materials because they can reduce costs and, at the same time, improve certain properties. On the other hand, their high moisture sorption and low microbial resistance are disadvantages that need to be cons…
Phase-separated blend films were prepared with the solution casting method from poly(L-lactide) (PLLA) and poly(ε-caprolactone) (PCL) with different PLLA contents [XPLLA (w/w) = PLLA/(PCL + PLLA)] and their biodegradation was investigated in soil up to 20 months by gravimetry, gel permeation chromatography, tensile te…
The kinetics of oxygen chemisorption on resin chars were investigated in this study. The Elovich equation was employed to facilitate the interpretation of the chemisorption process. It was found that the activation energy for chemisorption is not constant and varies with surface coverage. This observation can be expla…
Chromophores with optimized second-order optical nonlinearity to optical loss ratios are synthesized, poled with an electrical field, and coupled into hardened polymer matrixes. Acentric order, which is necessary for electro-optic activity, is optimized by the consideration of chromophore−chromophore electrostatic int…
This article reviews recent developments in multiresolution analysis which make it a powerful tool for the systematic treatment of the multiple length-scales inherent in the electronic structure of matter. Although the article focuses on electronic structure, the advances described are useful for non-linear problems i…
Polyethylene thin films are simulated on a high coordination lattice, which is formed by connecting every other site on a diamond lattice. The films present two surfaces to vacuum at 509 K. Each film contains 36 linear or cyclic chains of 50 beads on the coarse-grained lattice, where each bead represents two united-at…
Reactions of H 2 O 2 with Cp*MoCl 4 and Cp*WCl 4 (Cp* = C 5 Me 5 ) yield chloro oxo−peroxo complexes of the type Cp*MoO(O 2 )Cl ( 1 ) and Cp*WO(O 2 )Cl ( 2 ) in high yields. The compounds have been characterized using X-ray structural analysis.
The laser photolysis of gold Au III salts embedded in micelle cores of block copolymer micelles derived from polystyrene−poly-4-vinylpyridine was studied. Two types of polystyrene−poly-4-vinylpyridines having different block length have been employed, producing micelles with different properties. The influence of the…
For powder diffraction, high resolution can be best achieved using the parallel beam geometry with a monochromator/analyzer combination. However experiments are long and a way to reduce this time without compromising resolution is to use several analyzer/ detector combinations mounted on a single (theta) <SUB>a</SUB>/…
In this work we employed the layer-by-layer adsorption technique for deposition on solid substrates of polyionic films containing photoactive azobenzene groups. We investigated two systems, each having the same polyanion but using a different polycation. Poly {1-4[4-(3-carboxy-4-hydroxyphenylazo)benzenesulfonamido]-1,…
The growth process of selenium nanoparticles prepared in a microemulsion by a reverse micelle method is probed by several techniques. The smallest particles synthesized are of the order of 40 Å in diameter, producing the usual blue shift in the optical spectra. An amorphous to crystalline phase transition was detected…
Nanometer-sized gold clusters stabilized by monolayers of arenethiolates prepared using the Brust reaction are somewhat larger (by TEM) and less thermally stable (by TGA) than those prepared under similar conditions and stabilized by alkanethiolates. Like the latter, the mean core size decreases for synthetic conditio…