Materials Literature
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A series of homologous statistical polymethacrylate comb copolymers with tail-end 4-(dimethylamino)pyridinium ionic groups were synthesized by partial quaternization of high molar mass poly(12-bromododecyl methacrylate). The copolymers of lower ion content are found to be biphasic by differential scanning calorimetry,…
The electronic state of ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$ below the Verwey transition has been studied by x-ray resonant scattering at the iron K edge of the forbidden (0 0 2) and (0 0 6) reflections. These reflections are permitted by the anisotropy of the iron anomalous scattering factor. The energy and the azimut…
[figure: see text] A biphasic protocol for the catalytic olefin epoxidation with Mimoun-type complexes [MoO(O2)2(OPR3)] (1) was recently patented by BASF. Density-functional calculations have been carried out to identify potentially active species in addition to the parent complex 1. It has been found that the (mu 2,e…
Rb 2 Bi 8 Se 13 ( I ), Cs 2 Bi 8 Se 13 ( II ), CsBi 3.67 Se 6 ( III ), and BaBi 2 Se 4 ( IV ) were synthesized by direct combination reactions of the A/Se ( A = Rb, Cs, Ba) and Bi 2 Se 3 at ≥650 °C. Their structures were determined by single-crystal X-ray diffraction. Rb 2 Bi 8 Se 13 and Cs 2 Bi 8 Se 13 are isostructu…
High-pressure X-ray diffraction experiments on cubic ZrMo 2 O 8 have shown that the material undergoes a first-order phase transition involving an 11% volume decrease between 0.7 and 2.0 GPa under quasi-hydrostatic conditions. The transition is reversible upon decompression, but shows considerable hysteresis. Similar…
The anisotropic, two-dimensional structure of the compounds A 2 BaCu 8 Te 10 (A = K, Rb, Cs) fits the description of a “phonon glass electron crystal” (PGEC) which is proposed to be a desirable feature of a good thermoelectric material. It contains Cu 8 Te 12 pentagonal dodecahedral cages filled with Ba 2+ atoms. Thes…
Using a laser monitoring observation technique, the solubilities of 4-methylbenzoic acid in N -methyl-2-pyrrolidone, N, N -dimethylformamide, N, N -dimethylacetamide, trichloromethane, acetic acid, and water were measured by a synthetic method at temperatures ranging from 288 K to 370 K at atmospheric pressure. A solu…
Lattice constants, bulk moduli, band gaps, electronic bonding, and the stability of 20 new nitrides with spinel structure are studied by first-principles calculations. Double nitrides ${\mathrm{AB}}_{2}{\mathrm{N}}_{4}$ are found to be stable when the counterparts ${\mathrm{BA}}_{2}{\mathrm{N}}_{4}$ are metastable exc…
A series of Fe−zeolite-beta (Fe−BEA and 57 Fe−BEA) has been prepared either by exchanging BEA (Si/Al = 12.5) with Fe(NO 3 ) 3 or by impregnation. The identification of Fe species in Fe−BEA has been carried out by temperature-programmed reduction (TPR) with H 2 or CO and Mössbauer and DRIFT spectroscopies after various…
Wormhole HMS silica molecular sieves with average framework pore sizes in the range 2.9 to 4.1 nm were assembled from 4:1 molar mixtures of TEOS as the inorganic precursor (I o ) and dodecylamine as the structure-directing surfactant (S°) in 63:27 (v/v) water/ethanol. Increasing the assembly temperature from 25 °C to…
A series of double-comb, disubstituted polysiloxane polymers have been prepared containing oligoethylene oxide units, CH 3 (OCH 2 CH 2 ) n (CH 2 ) 3 −, in the side chains. These polymers were doped with LiN(SO 2 CF 3 ) 2 (LiTFSI, 1 ), and conductivities of the polymer-salt complexes were determined as a function of te…
The foaming of thin (∼100 μm) polysulfone (PSU), poly(ether sulfone) (PES), and cyclic olefin copolymer (COC) films using carbon dioxide as a physical blowing agent has been studied. Microcellular foam morphologies were obtained by saturating the polymer with carbon dioxide and heating the sample above the glass trans…
A theory for the ab initio calculation of all-electron NMR chemical shifts in insulators using pseudopotentials is presented. It is formulated for both finite and infinitely periodic systems and is based on an extension to the Projector Augmented Wave approach of Bloechl [P. E. Bloechl, Phys. Rev. B 50, 17953 (1994)]…
We present the theoretical design of quantum dot (QD) artificial ferromagnetic crystals. The electronic structure calculations based on local spin density approximation (LSDA) show that our designed QD artificial crystal from a structure comprising the crossing 0.104-micrometer-wide InAs quantum wires (an effective Ka…
Within a phenomenological approach the density of induced uniaxial anisotropy in nanostructures K(r) is treated as a physical field additional to the magnetization M(r). The equilibrium distributions of K(r) are formed under the influence of the surfaces and internal interactions. The functions K(r) and M(r) are calcu…
The fabrication, initial structural characterization and diode measurements are reported for the first boron carbide / silicon carbide heterojunction diode. Current-voltage curves obtained for operation at temperatures from 24 C to 388 C. PECVD-deposited undoped boron carbide material is highly crystalline and consist…
We study linear electron transport through a molecular wire sandwiched between nanotube leads. We show that the presence of such electrodes strongly influences the calculated conductance. We find that depending on the quality and geometry of the contacts between the molecule and the tubular reservoirs, linear transpor…
The structure of the multilayer assemblies of yttrium iron garnet nanoparticles (YIG) with polyelectrolytes was investigated with the emphasis on the control of the particle density in the adsorption layers. It was found that the growth of YIG films prepared by the layer-by-layer assembly can occur via two deposition…
A novel strategy to synthesize amphiphilic surface-compartmentalized nanoparticles based on linear ABC triblock copolymers is presented. These so-called Janus micelles consist of a cross-linked core and a corona with a “northern” and a “southern” hemisphere. Selectively cross-linking spherical domains of the polybutad…
The present work reports the synthesis and the characterization of cobalt oxide thin films obtained by chemical vapor deposition (CVD) on indium tin oxide (ITO) substrates, using a cobalt(II) β-diketonate as precursor. The complex is characterized by electron impact mass spectrometry (EI-MS) and thermal analysis in or…