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。
A fundamentally new single-walled and multiwalled carbon nanotube sidewall functionalization technique has been developed in which solvent is not required and the reaction times are greatly shortened (1 h at 60 degrees C). Exploiting the long linear dimension of the nanotube ropes by macroscopic mechanical deformation…
An extensive theoretical investigation of the nonpolar $(101\ifmmode\bar\else\textasciimacron\fi{}0)$ and $(112\ifmmode\bar\else\textasciimacron\fi{}0)$ surfaces as well as the polar zinc-terminated (0001)-Zn and oxygen-terminated $(0001\ifmmode\bar\else\textasciimacron\fi{})$-O surfaces of ZnO is presented. Particula…
We have performed magnetotransport measurements on La2/3Sr1/3MnO3/SrTiO3/La2/3Sr1/3MnO3 magnetic tunnel junctions. A magnetoresistance ratio of more than 1800% is obtained at 4 K, from which we infer an electrode spin polarization of at least 95%. This result strongly underscores the half-metallic nature of mixed-vale…
Liquid crystalline solutions of poly (p-phenylene benzoxazole) (PBO) in polyphosphoric acid (PPA) were prepared and studied. The typical banded texture and disclination of sheared PBO/PPA solution were observed by polarizing optical microscopy (POM), and the microstructure of the periodic aligned polymer chain that in…
Dust from steel processing is a heterogeneous, multicomponent mixture of metal oxides of zinc, lead, and iron, and several trace elements such as cadmium, nickel, cobalt, and copper. The hydrometallurgical separation and downstream processing of nonferrous metals from dust of electric arc furnaces (EAF) was investigat…
Abstract Syndiotactic polystyrene (sPS) and poly(phenylene oxide) (PPO) blends, miscible in the melt state, were crystallized from the melt and the quenched state at different temperatures. The effect of the crystallization temperature on the phase behavior of the blends and the polymorphic changes in sPS was investig…
At high supercoolings, isotactic polystyrene and polybutene-1 have a rounded crystal shape, suggesting kinetic roughening. Still, the growth rates of these polymer crystals show the supercooling dependence derived for nucleation controlled growth. On the other hand, isotactic poly-4-methylpentene-1 1,4 trans-polybutad…
The crystallization behavior of highly purified natural rubber (NR) was investigated by polarized light microscopy. NR was purified by enzymatic deproteinization followed by transesterification to remove nonrubber components present in the rubber. Nucleation rate and growth rate were estimated from a number of spherul…
Polyesteramide resin based on the condensation of hydroxyethylamide derivatives of fatty acids of soybean {N, N′‐bis(2 hydroxyethyl)soybean amide} and various dibasic acid and anhydride were synthesized. Physico‐chemical characteristics and film forming properties of these resins were determined to prove its suitabili…
Abstract In the second study on melt‐miscible syndiotactic polystyrene (sPS) and poly(phenylene oxide) (PPO) blends, the effect of processing conditions on morphology, ultimate tensile properties, and the mode of fracture is reported. Bulk samples of the blends were molded and then crystallized from melt as well as fr…
The crystal structure of the clathrate form of syndiotactic poly( m -methylstyrene) containing carbon disulfide is presented. The structure is characterized by polymer chains in s (2/1)2 helical conformation and CS 2 molecules packed in an orthorhombic unit cell with axes a = 17.8 Å, b = 13.1 Å, and c = 7.8 Å, accordi…
The ordering process of poly(ethylene terephthalate) (PET) from the oriented glassy states during the isothermal annealing process was investigated using real-time X-ray scattering experiments with synchrotron radiation sources. The X-ray scattering intensity of the 001' reflection, which is a measure of the smectic o…
The crystallization kinetics of isotactic polypropylene (iPP) and nucleated iPP with two organic phosphates, sodium salt (NA7) and triglyceride ester (NA8) of 2,2'-methylene-bis(4,6-di-tert-butylphenyl) phosphoric acid, were investigated by means of a differential scanning calorimeter under isothermal and nonisotherma…
Effect of the shear flow (γ˙=0.5∼5 s−1) on the nucleation and on the morphology of polyethylene (PE) during crystallization from the melt was studied by means of polarizing optical microscopy and small angle X-ray scattering. In order to analyze the results by the nucleation theory, we observed the effect of shear flo…
In this paper we study a Landau–de Gennes model of a nematic liquid crystal in a model shear flow employing a range of analytical and numerical techniques. We use asymptotic methods and numerical bifurcation theory to provide a comprehensive description of the different in–plane modes that exist in terms of the temper…
We examined the free surface of a banded spherulite of poly (vinylidene fluoride) (PVDF) by atomic force microscopy. The directions of the slope of multilayer terraces of lamellar crystals are retained in each half of a banded spherulite; this evidence confirms the macroscopic selection of one-handedness in the format…
Direct evidence that nuclei are formed during the induction period of crystallization is obtained for the first time by means of small-angle X-ray scattering (SAXS). Polyethylene (PE) was used as a model crystalline polymer. The nucleating agent was mixed with PE in order to increase the scattering intensity I x from…
Abstract A new type of hyperbranched polysilazane containing iron (PSZI) compound was synthesized by the polycondensation of silazane lithium salts with FeCl 3 , and the structure of the PSZIs was investigated by IR, NMR and elemental analyses. The PSZIs were pyrolyzed under nitrogen, argon or NH 3 , and magnetic cera…
Copolymers (2‐HAOF), synthesized by the condensation of and H2N(O)CC(O)NH2 with CH2O in the presence of acid catalyst, proved to be selective chelating ion‐exchange copolymers for certain metals. The chelating ion‐exchange properties of this copolymer were studied for Cu(II), Ni(II), Co(II), Zn(II), Fe(III), Cd(II) an…
Organic phosphates used as nucleating agents can remarkably promote the stiffness and crystallization rate of polypropylene homopolymer and ethylene–propylene copolymer. In this article, the nucleating activity of 2,2′-methylene-bis(4,6-di-tert-butylphenyl) phosphoric acid and its derivatives for isotactic polypropyle…