Materials Literature
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Abstract The process of low‐melting point (LMP) α‐phase formation in a quenched and annealed isotactic polypropylene (iPP) was studied by means of differential scanning calorimetry. The influence of preparation conditions (quenching and annealing temperatures, annealing times and sample thickness), together with the m…
We present lattice-gas modeling of the steady-state behavior in CO oxidation on the facets of nanoscale metal clusters, with coupling via interfacet CO diffusion. The model incorporates the key aspects of the reaction process, such as rapid CO mobility within each facet and strong nearest-neighbor repulsion between ad…
Abstract Biodegradable poly(ester amide)s that contained phenylalanine residues in the main chains were synthesized by the polycondensation of di‐ p ‐nitrophenyl sebacate and phenylalanine 2‐aminoethyl ester. The stereoisomeric composition ( L / D ratio) of the phenylalanine residue in the monomer did not affect the y…
A series of dimethylsiloxane linked cyanate ester monomers (NCOC 6 H 4 (CH 2 ) 3 (Si(CH 3 ) 2 O) n Si(CH 2 ) 3 C 6 H 4 OCN, n = 1, 2, 3) have been synthesized and characterized. Monomer melting points range from 5 to −12 °C, and characterization includes 1 H, 13 C NMR, and IR spectroscopies and DSC. Thermoset formatio…
The mesomorphic behavior of several new end-functionalized liquid-crystal-containing dendrimers is reported. These liquid-crystalline dendrimers are obtained by attaching promesogenic units to the termini of the preexisting first five generations of poly(amidoamine) (PAMAM) and poly(propyleneimine) (DAB) polymers by a…
We report on the design and synthesis of a new disclike mesogen based on a 3,5-dicyano-2,4,6-tristyrylpyridine core. This compound was characterized by spectroscopic methods (NMR, UV−vis, and photoluminescence) and cyclic voltammetry. The mesogenic behavior was investigated by differential scanning calorimetry, polari…
The first step in the biosynthetic pathway of vitamin C in plants is the formation, at the level of sugar nucleotide, of l-galactosyl residues, catalyzed by a largely unknown GDP-d-mannose 3",5"-epimerase. By using combined conventional biochemical and mass spectrometry methods, we obtained a highly purified preparati…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTFrom Membranes to Melts, Rouse to Reptation: Diffusion in Polymersome versus Lipid BilayersJames C.-M. Lee, Maria Santore, Frank S. Bates, and Dennis E. DischerView Author Information School of Engineering and Applied Science, Unive…
Equilibrium adsorption isotherms for methane, ethane, ethylene, acetylene, propane, and propylene have been measured for the first time on mesoporous silica, SBA-15, and the data are analyzed by using the Langmuir−Freundlich adsorption isotherm model. The adsorption capacities for ethylene and propylene are found to b…
We consider a mean field model describing the free cooling process of a two component granular mixture, a generalization of so called Maxwell model. The cooling is viewed as an ordering process and the scaling behavior is attributed to the presence of an attractive fixed point at $v=0$ for the dynamics. By means of as…
Nanocomposites of polypropylene- graft -maleic anhydride with organically modified clays have been prepared and characterized by X-ray diffraction and transmission electron microscopy. Their combustion behavior has been evaluated using oxygen consumption cone calorimetry. Synergy is observed between the nanocomposite…
In this work, we present results of a periodic density-functional theory study of the adsorption of carbon monoxide (CO) and hydroxyl (OH) on platinum, ruthenium, and a series on platinum−ruthenium alloys. The surfaces are modeled as four-layer slabs. The binding energies and geometries of CO and OH are computed, as w…
A new approach for the synthesis of colloidal gold shell particles with a dielectric core is described. Small gold nanoclusters were attached to the functionalized surface of colloidal silica particles. Reductive growth and coalescence of these clusters lead to the formation of a closed gold layer. By variation of the…
A pseudo-pentagonal kernel is the central unit in the new quaternary intermetallic phase Li10Mg6Zn31Al3 (see structure). This unit can form the basis for decagonal and, possibly, icosahedral quasicrystals. The synthesis, crystal structure, and bonding of Li10Mg6Zn31Al3 are discussed in detail.
Ein trifunktioneller matrixgebundener Katalysator auf Basis der Metalle Pd, Os und W wurde für die Eintopf-Mehrstufen-Synthese von chiralen Diolen genutzt (siehe Schema; LDH=Schicht-Doppelhydroxid, (DHQD)2PHAL=1,4-Bis(9-O-dihydrochinidinyl)phthalazin, NMM=N-Methylmorpholin).
C3-symmetrische Lactame in der Röhre: Eigens entworfene starre Macrolactamscheiben ordnen sich über Rückgrat-Rückgrat-Wasserstoffbrücken und Van-der-Waals-Kontakte als Endlosröhren an (siehe Schema). Die Röhren bilden wiederum parallel angeordnete Aggregate aus gleichförmig ausgerichteten Dipolen.
Antiferroelectric lead zirconate titanate (PZT) thin films have been prepared by chemical solution deposition using oxide powders. The films were processed onto steel substrates coated with a conducting oxide layer of LaSrMnO3. Homogeneous and uniform films up to 3.4 μm thick and with polarization saturation values up…
Contrasting calixarenes: Thermodynamically stable and water-soluble calix[4]arene–LnIII (see picture) complexes may represent a new class of relaxation (Ln=Gd) or luminescent (Ln=Eu, Tb) probes for biomedical studies. The first complete characterization of one of these complexes in water is reported. The GdIII chelate…
A transition metal based biomimic approach is used to realize multistep reactions, composed of multicomponent systems, in a single-pot synthesis of chiral diols mediated by a trifunctional (Pd, Os, W) catalyst anchored to a single matrix (see scheme; LDH=layered double hydroxide, (DHQD)2PHAL=1,4-bis(9-O-dihydroquinidi…
A Ni4O2 core based on a “chair” topology forms the central unit of the tetranuclear nickel(II) complex 1, which possesses μ3-OH− and butane-2,3-dione-monooximate bridges and displays fascinating magnetic properties. The major Ni–Ni interactions in 1 are antiferromagnetic in nature, and the large Nicore-O-Niterminal an…