Materials Literature
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[reaction: see text] Novel spiroheterocyclic molecules, namely, 2,3-dihydro-2-spiro-7'-[8'-imino-7',8'-dihydronaphthalen-1'-amine]perimidine, PNI, and 2,3-dihydro-2-spiro-4'-[8'-aminonaphthalen-1'(4H)-one]perimidine, PNO-p, were obtained by oxidation of 1,8-diaminonaphthalene using manganese dioxide. These molecules e…
Abstract A new computational approach is developed based on the mesh‐free method for the numerical simulation of shape memory alloys. A thermomechanical constitutive model is used to describe the complex material response. The incremental displacement‐based mesh‐free formulation is constructed in a total Lagrangian de…
The factors that determine the miscibility of two polymers, each of which hydrogen bonds (self-associates) to itself in the pure state, is discussed. Equations describing the contributions of hydrogen bonding to the free energy of mixing are presented. It is shown that mixtures of this type are much less likely to be…
Abstract To investigate the joint effect on shock wave propagation and attenuation in jointed rock masses, a small-scale field explosion test is analyzed numerically by using the three-dimensional discrete element method (3D DEM) and the three-dimensional finite difference method (3D FDM). Results show that rock joint…
We consider helical configurations of a cholesteric liquid crystal (CLC) sandwiched between two substrates with homogeneous director orientation favored at both confining plates. We study the CLC twist wave number q characterizing the helical structures in relation to the free twisting number q(0) which determines the…
We report a complete analysis of the formal Co 3+/4+ oxidation state in Na x CoO 2, in the interval 0.31 ≤ x ≤ 0.69. Iodometric titration and thermoelectric power confirm that a direct relationship between the Na content and the amount of Co 3+ cannot be established in this system. Creation of a significant amount of…
Aligned double-walled carbon nanotube (DWNT) long ropes with a narrow diameter distribution were directly synthesized by sulfur-assisted floating catalytic decomposition of methane. The DWNT ropes are typically up to several centimeters in length and possess good alignment and high purity. High-resolution transmission…
Abstract Thermolysis of Fe(CO) 5 and Co 2 (CO) 8 , dissolved in tetrahydronaphthalene, in the presence of aluminum trialkyl leads to uniform‐sized Fe or FeCo nanoparticles, respectively. Subsequent treatment with very dilute oxygen forms a shell which protects the metallic or alloyed core of the particles against fur…
Abstract This article presents the results of TMC and DMC polymerization with the use of acetylacetonates of low‐toxic metals: iron, zinc, and zirconium. Zinc (II) acetylacetonate proves to be a very good initiator of homopolymerization. The reaction carried out with the use of this initiator at 110 °C is very rapid a…
We report here a modular approach for the construction of a new class of compounds, the Hangman salophens. In the Hangman motif, an acid-base functionality "hangs" over the face of a redox cofactor. In contrast to more synthetically intractable porphyrin-based Hangman systems, Hangman salophens permit the facile contr…
The Seebeck coefficient of the ${\mathrm{Ti}}_{3}{\mathrm{SiC}}_{2}$ compound has recently been measured and found to be constant and negligible over a wide range of temperature. Materials with essentially zero thermopower allow us to measure the absolute thermopower of another material and could therefore be consider…
A Stokes experiment for foams is proposed. It consists of a two-dimensional flow of a foam, confined between a water subphase and a top plate, around a fixed circular obstacle. We present systematic measurements of the drag exerted by the flowing foam on the obstacle versus various separately controlled parameters: fl…
The direct electropolymerization of benzene dissolved in the ionic liquid 1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate was studied at room temperature applying the electrochemical quartz-crystal microbalance technique. Analysis of the damping changes showed that the Sauerbrey equation could be…
A supramolecular propeller: A trinuclear EuIII helix with six chiral bipyridine-carboxylate ligands self-assembles with complete diastereoselectivity (see graphic; Eu green, O red, N blue). Ground- and excited-state chiroptical properties of this red-emissive complex reflect the helical arrangement of the ligands arou…
Abstract N‐doped p‐type ZnO thin films were grown by plasma molecular beam epitaxy (P‐MBE) on c ‐plane sapphire (Al 2 O 3 ) using radical NO as oxygen source and nitrogen dopant. The reproducible ZnO thin films have maximum net hole concentration ( N A – N D ) of 1.2 × 10 18 cm –3 and minimum resistivity of 9.36 Ω cm.…
Abstract A molybdenum‐containing preceramic polymer, MoPMS, was synthesized for the first time by HCl elimination of polymethylsilane (PMS) and MoCl 5 at room temperature in tetrahydrofuran. The insoluble MoPMS prepared was embedded into the void spaces of a silica colloidal crystal template within the pot life of the…
Abstract For Abstract see ChemInform Abstract in Full Text.
Abstract Two families of electrically‐conductive immiscible polymer blends were studied as liquid sensing materials for an homologous series of alcohols. The systems studied include: multiphase matrices [containing carbon black (CB)] consisting of either polypropylene or high‐impact polystyrene as the major phase and…
Je einfacher, desto besser: Phenol entsteht durch direkte Oxidation von Benzol in einer Atmosphäre aus Luft (15 atm) und CO (10 atm) mit Molybdovanadophosphorsäure als Katalysator (siehe Schema). Aktivierter molekularer Sauerstoff dient als Oxidationsmittel, und Phenol wird in 28 % Ausbeute gebildet. Der Katalysator k…
Spin doctored: In reactions with phenolate anions, the (tetraisopropylcyclopentadienyl)iron fragment forms low-spin or high-spin iron(II) complexes with different coordination geometries. The lithium complex 1 allows a direct comparison of low-spin and high-spin cyclopentadienyliron fragments within one molecule.