Materials Literature
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[structure: see text] A new approach to polyacetal systems using sequential transacetalation and protection-deprotection techniques was developed for the preparation of macromolecular polyacetals and applied to secure new dendrimers with 2,4,8,10-tetraoxaspiro[5,5]undecane dendrons from pentaerythritol and polyaldehyd…
Electrospray ionization (ESI) mass spectrometry is a soft-ionization technique that allows analysis of exact structure, composition, and stability of solution phase materials by a gas-phase technique. We describe the application of ESI techniques for the analysis of a nanoscale material, [Cd 32 S 14 (SC 6 H 5 ) 36 ·DM…
The energy migration ${}^{3}{\mathrm{H}}_{4}{,}^{3}{\mathrm{H}}_{6}\ensuremath{\rightarrow}{\mathrm{H}}_{4}{,}^{3}{\mathrm{H}}_{6}$ and the cross relaxation ${}^{3}{\mathrm{H}}_{4}{,}^{3}{\stackrel{\ensuremath{\rightarrow}}{{\mathrm{H}}_{6}}}^{3}{\mathrm{F}}_{4}{,}^{3}{\mathrm{F}}_{4}$ between ${\mathrm{Tm}}^{3+}$ ion…
Abstract Nonradiative energy transfer method was used to study latex film formation induced by organic solvent vapor. Seven different films with the same latex content were prepared separately from poly(methyl methacrylate) (PMMA) particles and exposed to ethyl benzene, toluene, chloroform, dichloromethane, tetrahydro…
Abstract Chlorinated ground rubber tire (Cl‐GRT) particles were used as filler in a plasticized polyvinylchloride (PVC) to develop a melt‐processable rubber composition. Physical properties of the Cl‐GRT‐filled PVC compound showed improvement compared to the nonchlorinated counterpart. Interaction between Cl‐GRT and P…
A promising route to strictly one-dimensional arrangements of Au 55 (PPh 3 ) 12 Cl 6 clusters is described. On the basis of the successful generation of ordered two-dimensional cluster architectures by self-assembly processes at the phase boundary between water and dichloromethane, the formation of single cluster rows…
Abstract The properties of ionic elastomers formed in the crosslinking with zinc peroxide are studied in compounds with varying proportions of carboxylic groups in the elastomeric matrix. At the temperature used, 150°C, preferentially ionic bonds were formed. The crosslinking densities and, correspondingly, the physic…
La2CoMnO6 perovskite manganite was synthesized by solid-state reaction. Rietveld refinement of powder x-ray diffraction data indicated that this compound crystallized with an orthorhombic structure containing distorted (Co/Mn)O6 octahedra (Pnma; a = 5.5 A; b = 7.2 A; c = 5.4 A. The dc magnetization and real part (x')…
Abstract Anionic ring‐opening polymerization of propylene oxide in the presence of potassium alcoholate initiator was accelerated by addition of the bulky phosphonium salt tetrakis[cyclohexyl(methyl)amino]phosphonium‐tetrafluoroborate. Dipropylene glycol (DPG) was partially deprotonated (5%) and used as an initiator f…
The electronic structure of the molecular solid $\mathrm{Ni}(\mathrm{tmdt}{)}_{2},$ the only well characterized neutral molecular metal to date, has been studied by means of first-principles density functional calculations. It is shown that these calculations correctly describe the metallic vs semiconducting behavior…
The influence of a bulky, strongly coupled substituent (benzoyl−phenyl−ethenyl, BPE) on the dynamics of the photoinduced ring-closure and ring-opening reactions of 1,2-bis[[2−methyl−thien−3−yl]]perfluorocyclopentene (BMTFP) in solution was investigated. UV/vis absorption spectroscopy in combination with chemical actin…
Abstract Rosin‐based polyester polyols were synthesized from a rosin–maleic anhydride adduct, diethylene glycol, and ethylene glycol with and without adding adipic acid and phthelic anhydride, in the presence of catalyst. Rigid polyurethane (PU) foams were prepared with these rosin‐based polyols and compared with foam…
A highly efficient functional mimic of a photosynthetic antenna−reaction center complex has been designed, synthesized, and studied spectroscopically. The antenna, consisting of four covalently linked zinc tetraarylporphyrins, (P ZP ) 3 −P ZC, has been coupled to a free-base porphyrin−fullerene artificial photosynthet…
The photophysical properties of the triple-stranded dimetallic helicates [Ln 2 (L C −2H) 3 ]·H 2 O (Ln = Nd, Sm, Dy, Yb) are determined in water and D 2 O solutions, and energy transfer processes are modeled for Sm III . The luminescence of Nd III, Sm III, and Yb III is sensitized by (L C −2H) 2-, but the energy trans…
Abstract A new metal‐free synthetic approach to the controlled ring‐opening polymerization (ROP) of lactide with nucleophilic phosphines as transesterification catalysts is described. P(Bu) 3 , PhPMe 2 , Ph 2 PMe, PPh 3 , and related phosphines are commercially available, inexpensive catalysts that generate narrowly d…
Abstract A new kind of polyol based on rape seed oil for use in rigid polyurethane foam was synthesized and characterized. The synthesis of such a polyol was divided into two steps. The first step was the hydroxylation of the double bonds existing in the long chains of the unsaturated aliphatic hydrocarbon of rape see…
The question how to introduce thermal fluctuations in the equation of motion of a magnetic system is addressed. Using the approach of the fluctuation-dissipation theorem we calculate the properties of the noise for both, the fluctuating field and fluctuating torque (force) representation. In contrast to earlier calcul…
Four plasma proteins have been shown to be able to mediate platelet adhesion to synthetic materials when they are adsorbed as purified proteins: fibrinogen (Fg), fibronectin (Fn), vitronectin (Vn), and von Willebrand factor (vWF). Among them, Fg is thought to play a leading role in mediating platelet adhesion to plasm…
We prepared the brownmillerite oxide Ca_{2-y}La_yCo_{2-x}Al_xO_5, and found that it was an n-type conductor. The thermopower and the resistivity of the single crystal are -90 microV/K and 68 mOhm cm along the ab direction at 440 K, which suggest relatively good thermoelectrical properties, compared with other transiti…
The photoluminescence (PL) quantum yield (QY) of CdSe nanocrystals during their growth under a given set of initial conditions increases monotonically to a certain maximum value and then decreases gradually. Such a maximum is denoted as a PL "bright point", which does not always overlap with the minimum point of the P…