Materials Literature
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When there is a hole in a chemically cross-linked gel, the phase transition from swollen to shrunken phase starts at the free surface of the hole. The growth of the new phase is, however, arrested eventually around the hole with a finite thickness depending on controlling parameters such as temperature. This phenomeno…
We perform Monte Carlo simulations of the pouring of hard ellipsoids into a three-dimensional container. Both oblate and prolate ellipsoids of revolution are examined. Oblate ellipsoids pack so that their symmetry (semi-minor) axes are preferentially aligned with the direction of gravity, and their orientational align…
Abstract The physical properties of unmodified starch, poly(ethylene vinyl alcohol), glycerol, and water mixtures are reported. Thermal and melt‐flow properties of the preprocessed, physically mixed materials were determined along with the tensile properties and morphology of injection‐molded microtensile samples. Mel…
Optical properties of stretched Mylar films [poly(ethylene terephthalate)] were evaluated. Similar birefringence dispersion to liquid crystals over a wide spectral range makes Mylar an attractive phase retardation plate for display applications. Two display modes employing an antiparallel (or π) and a parallel-aligned…
Je Monomer‐Einheit doppelt deprotoniert , als Chelatligand an Cu 2+ gebunden und versteift durch starke Wasserstoffbrückenbindungen des Typs O‐H…O − ‐so liegt Cellulose in Schweizers Reagens vor (Bild rechts), das seit 1857 bekannt und heute Grundlage eines technischen Prozesses zur Membranherstellung ist. Die neuen E…
Far-reaching analogies between μ-oxodiiron(III) complexes of porphycenes and porphyrins with regard to physical, chemical, and structural properties are revealed by investigations of the new metallopor-phycenes 1 (R nPr, tBu). These are obtained by using standard methods for porphyrin chemistry. The Fe-O-Fe angle in…
Single-crystal neutron-diffraction measurements on cobalt tungstate. CoWO 4 , at 15 K and powder measurements in the temperature interval 5-55 K have confirmed that it orders antiferromagnetically below its Neel temperature of 55 K with a magnetic propagation vector ( 1/2 0 0). The chemical unit cell is monoclinic, sp…
We have investigated the formation of textured and epitaxial metallic films on (100) MgO single crystals substrates (lattice constant a=4.21 Å) as a function of deposition temperature during pulsed laser ablation. Platinum (a=3.92 Å) films on MgO with lattice misfit of 7.4% were found to grow epitaxially in the temper…
Abstract The spontaneous spreading of small liquid droplets on solid surfaces is examined with the objective of developing closed‐form expressions for the spreading dynamics, both for the case in which there is complete equilibrium spreading, that is the equilibrium contact angle is 0°, and for the case in which equil…
The synthesis of new, medium‐sized copper clusters with unusual structures and a successful combination of experiment and theoretical calculation—this is offered by the present communication. The reaction of CuAc with PR 2 R′ (R, R′ Et, Ph) and E(SiMe 3 ) 2 (E S, Se) leads to the clusters 1–4 . Several of these mi…
GaInO3, a layered material with the β Ga2O3 crystal structure, can be doped with electrons through the introduction of oxygen deficiency, Sn doping for In, or Ge doping for Ga. At atomic doping levels of 10% or less, resistivities as low as 3 mΩ cm are obtained. In contrast to polycrystalline indium tin oxide (ITO), w…
Simply heating a suspension of [Ph4P][VO2Cl2] and tBuPO3H2 in acetonitrile in a sealed tube to 100°C gave the first of the three title compounds as dark green crystals. The structure of this compound (shown on the right) could not have a more pleasing simplicity. Relatively minor changes in the starting materials led…
We report here on the high-density preparation of single-wall tubes in the presence of mixed catalysts of the types Fe/Ni and Co/Ni, in the soot as well as in the weblike deposits forming in the chamber. The yield is much higher than previously reported, and gram quantities can be obtained. Diameters cover the range f…
X-ray absorption measurements from H-passivated porous Si and from oxidized Si nanocrystals, combined with electron microscopy, ir absorption, \ensuremath{\alpha} recoil, and luminescence emission data, provide a consistent structural picture of the species responsible for the visible luminescence observed in these sa…
Abstract Increasing demands to decrease engine weight and improve engine performance has led to an investigation to develop polymer composites capable of being used at 371°C and above in 4 atmospheres of air. The results of an investigation to determine the thermo‐oxidative stability (TOS) of various fluorinated polyi…
We report a novel approach for obtaining precise control of both p- and n-type dopant concentrations in bulk Ge single crystals. High-purity Ge single crystals of controlled 74Ge/70Ge isotope composition ratios were grown and subsequently doped by the neutron transmutation doping (NTD) technique. The resulting net-imp…
Neutral molecules are encapsulated in the cluster anions in the title, which were produced by solvothermal reactions of [nBu4N]3[H3V10O28] and PhAsO3H2 in CH3OH/H2O (99:1) with and without Et4NCl. The structures are shown schematically below.
We demonstrate here that the pattern evolution in a binary liquid mixture containing glass spheres is strongly affected by the dynamic coupling between phase separation and wetting. Because of the difference in the wettability to glass between the two phases, the glass particles are preferentially included in the more…
Vertex‐sharing BO 4 and PO 4 tetrahedra form the framework of the title compounds. Ca[BPO 5 ] and Sr[BPO 5 ] crystallize in the stillwellite structural type and contain tetrahedral chain anions [BPO ], which can be described as loop‐branched “dreier” single chains. In Ba 3 [BP 3 O 12 ] the tetrahedral anions form “zwe…
The unusual oxidation state + IV for iron centers can be stabilized by porphyrin-like corrole ligands in such a way that the compounds 1 (R Cl, Ph, OFe-corrole) can be isolated at room temperature. The oxygen-bridged binuclear iron(IV) corrole, which can be readily converted into the mononuclear iron(IV) corrole, fo…