Materials Literature
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We successfully synthesized carbon nanotubes with very small diameters (5–10 nm) at room temperature by using high energy laser pulses (193 nm, 5 J/cm 2 and 20 ns duration time) to re-excite the carbon species contained in the laser ejected plume. The carbon nanotubes, which presumably formed in gas phase, were prefer…
A thermodynamically consistent phase-field model with memory, based on the linearized version of the Gurtin-Pipkin heat conduction law, is considered. The formulation of an initial and boundary value problem for the phase-field evolution system is framed in a history space setting. Namely, the summed past history of t…
Vacuum sublimed thin films of copper phthalocyanine wereprepared at room temperature. The optical properties of thin CuPc filmshave been investigated in the spectral range 200-2100 nm. The refractiveindex n as well as the absorption index k were calculated before and afterannealing. It is obvious that the refractive i…
The photodynamic therapy (PDT) related photophysical properties of five palladium(II) porphyrins with increasing steric demand of the meso-substituents were investigated by steady state and time-resolved absorption and luminescence spectroscopy. The steric strain of the meso-substituents is reflected in a bathochromic…
Orotidine 5'-phosphate decarboxylase (ODCase) is the most proficient enzyme known, enhancing the rate of decarboxylation of orotidine 5'-phosphate (OMP) by a factor of 10(17), which corresponds to a DeltaDeltaG++ of approximately 24 kcal/mol. Ground-state destabilization through local electrostatic stress has been rec…
Abstract The ratio of the pure‐component solubility of a primary solute to that of an impurity in the same solvent has a dramatic impact on crystal purity when lattice substitution is the dominant mechanism of impurity incorporation in the crystal. This is demonstrated for a model system of isoleucine and leucine in w…
Abstract Muscovite-kaolinite intergrowths found in Albian sandstones of the Basque Cantabrian basin (northern Spain) were studied by optical, scanning and electron microscopy and electron microprobe analysis. Kaolinitization begins at grain edges, forming the characteristic fanned-out textures, and propagates toward t…
A new and general synthetic strategy for thiophene-based condensed aromatics(see Figure) is described. A tandem cyclization scheme produces aromatized monomers in situ, prior to oxidative polymerization. The poly(naphthodithiophene)s are a family of highly stable and polarizable scaffolds whose polymer backbone energe…
Abstract A novel spin crossover Fe(III) complex, [Fe(H3L)](ClO4)3·(4-fim)·H2O (H3L = tris[2-(((imidazol-4-yl)methylene)amino)ethyl]amine, 4-fim = 4-formylimidazole), was synthesized and the crystal structure was determined at 293 K. Cryomagnetic measurements revealed a two-step spin conversion and a pressure induced s…
Well-ordered Georgia kaolinite (Kga-1b) obtained from the source Clay Repository of the Clay Minerals Society (USA) was intercalated with urea using grinding procedures. To achieve complete intercalation 20% of urea (in weight) was used, producing Al2Si2O5(OH)4 (N2H4CO)0,86 with an interplanar basal spacing of 1,08nm.…
Abstract Mechanical properties and morphologies of nylon 11/ethylene‐octene copolymer blends have been investigated. The ethylene‐octene copolymer (POE) employed in this study was grafted with maleic anhydride (MAH) and thus has the potential to react with the amine group of nylon 11. Nylon 11/POE‐g‐MAH and nylon 11/P…
The effect of the addition of Bi 2 O 3 on the densification, low‐temperature sintering, and electromagnetic properties of Z‐type planar hexaferrite was investigated. The results show that Bi 2 O 3 additives can improve the densification and promote low‐temperature sintering of Z‐type hexaferrite prepared by a solid‐st…
The effects of divalent salts (CaCl 2, MgCl 2 and BaCl 2 ) in promoting the adsorption of weakly charged polyelectrolyte (polyacrylic acid), PAA, Mw ∼ 250000 g/mol) on mica surfaces and their role in tuning the nature of interactions between such adsorbed polyelectrolyte layers were studied using the interferometric s…
Die Verbindungen A8[Ta6O19] · n H2O (A = Rb, Cs; n = 0, 4, 14) enthalten das Isopolyanion [Ta6O19]8–, das aus sechs zu einem großen Oktaeder kantenverknüpften [TaO6]-Oktaedern besteht. Sie gehen – wie u. a. die thermoanalytischen Untersuchungen (TG/DSC) zeigen – durch reversible Hydratations/Dehydratationsprozesse ine…
An oriented gas model for the second-order nonlinear optical response for optical second-harmonic generation in axially aligned nonlinear optical chromophores in chiral media is presented. Design criteria for the alignment of chromophores possessing Kleinman-disallowed traceless symmetric second-rank tensor hyperpolar…
Abstract Supercritical carbon dioxide (scCO 2 ) was added during blending of polystyrene or poly(methyl‐methacrylate) (PMMA) and a rubber impact modifier (SP 2207). The resulting blend morphologies were compared. The compounding took place in a Leistritz ZSE‐27 twin‐screw extruder at 100 RPM, at a temperature of 200°C…
Abstract A precursor poly(amic acid) was obtained by solution polymerization of pyromellitic dianhydride and benzidine in N, N‐dimethylacetamide. Poly(amic acid)/Organoclay hybrids were prepared by the solution intercalation method with dodecylamine‐montmorillonite. A polyimide hybrid was obtained from poly(amic acid)…
A broadband dielectric study of the dispersions of silica spheres (Aerosil 380) in octylcyanobiphenyl (8CB) with densities between 0.083 and 10 g of silica per 1 cm 3 of liquid crystal (LC) is reported. High values of silica densities were achieved for the first time to observe the behaviour of the LC monolayer on the…
The synthesis and characterization of the new aromatic ortho-dithiol, 4,5-dicyanobenzene-1,2-dithiol (3) is reported. This compound was used to prepare tetrabutylammonium salts of novel nickel complexes; the nickel(II) salt (nBu4N)2[Ni(dcbdt)2] (4), the nickel(III) salt (nBu4N)2[Ni(dcbdt)2]2 (5), and the partially oxi…
A chitin-based graft copolymer, chitin-graft-oligo(ε-caprolactone) (2), was synthesized via ring-opening graft polymerization of (ε-caprolactone (ε-CL) to ca. 50% partially deacetylated chitin 1 catalyzed by tin(II) 2-ethylhexanoate in the presence of water as a swelling agent. The graft copolymer with ca. 40 wt.-% po…