Materials Literature
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Nanoblended multilayer thin films were formed by the layer-by-layer assembly of poly(allylamine hydrochloride) (PAH) and a binary mixture of single-stranded deoxyribonucleic acid (DNA) and poly(sodium styrenesulfonate) (PSS). UV−vis spectrophotometry was used as a facile means to determine the proportion of DNA and PS…
Heterometallic linear tetramers [Mn(5-R-saltmen)Ni(pao)(bpy)(2)](2)(ClO(4))(4) (5-R-saltmen(2-) = N,N'-1,1,2,2-tetramethylethylene bis(5-R-salicylideneiminate); pao(-) = pyridine-2-aldoximate; bpy = 2,2'-bipyridine, R = H, 1; Cl, 2; Br, 3; MeO, 4) have been synthesized and structurally characterized. These compounds e…
We have performed density functional theory−generalized gradient approximation periodic calculations to study the formation of an oxygen vacancy on rutile-TiO 2 (110), rutile-SnO 2 (110), and MgO(100) surfaces assuming that the removed O atom remains adsorbed in the neighborhood of the vacancy (surface Schottky defect…
The variation of the lattice vibration of spinel lithium manganate upon chromium substitution has been investigated by performing a combinative micro-Raman and X-ray absorption spectroscopic (XAS) analysis. As the manganese ion in the spinel LiMn 2 - x Cr x O 4 is replaced by a chromium ion, the relative intensities o…
Sr 2 CeO 4 blue phosphor particles were prepared with an emulsion liquid membrane (ELM, water-in-oil-in-water (W/O/W) emulsion) system, which could be utilized as a microreactor for the preparation of size- and morphology-controlled fine particles. In the ELM system, Sr 2+ and Ce 3+ ions were extracted from the extern…
Nanochannel arrays with diameters as small as 30 nm and aspect ratios up to 250 were prepared on silicon platforms for the first time by electrochemistry, which is a fast, reproducible, and inexpensive technique. Ionic diffusion through the arrays was investigated in order to demonstrate the open nature of the channel…
The non-mesogenic ligand L 1, derived from a 1,7-diaza-18-crown ether, forms mesogenic complexes with Eu III and Tb III nitrates, Eu(NO 3 ) 3 L 1 ·0.25 H 2 O ( EuL 1 ) and Tb(NO 3 ) 3 L 1 ·1 THF ( TbL 1 ). Thermal analyses and polarized light microscopy data indicate the formation of a liquid-crystalline phase at 86 (…
Carbon nanotubes, mostly single- and double-walled, are prepared by a catalytic chemical vapor deposition method using H 2 −CH 4 atmospheres with different CH 4 contents. The maximum hydrogen storage at room temperatures and 10 MPa is 0.5 wt %. Contrary to expectations, purification of the carbon nanotube specimens by…
ε-Caprolactone was polymerized in bulk at 150 °C with either tetra(ethylene glycol) (TEG), 1,1,1-tris(hydroxymethyl)propane, or Pentaerythritol as initiator and bismuth(III) acetate Bi(OAc) 3 as catalyst. The reaction times needed for nearly quantitative conversion were determined. The polylactones isolated after prec…
An introductory series of conjugated siloleneethynylene co-oligomers has been prepared from a key 2-chloro-5-iodosilole intermediate via site-specific cross-coupling reactions. The tetramer (9) and pentamer (10) both exhibit absorption maxima matching those of the corresponding silole copolymers. Extinction coefficien…
We report on the surface behavior of the asymmetric heteroarm poly(ethylene oxide) (PEO)/polystyrene (PS) star polymer on the air−water interface on a solid substrate. These amphiphilic star polymers with different numbers of hydrophobic arms and a similar hydrophilic block differ by architecture (four and three arm m…
The structures and electrochemistry of N-benzylated meso-tetrakis (3,5-di-tert-butyl-4-oxo-cyclohexa-2,5-dienylidene) porphyrinogens have been investigated. Structural determinations reveal the isomeric identity of the products obtained from the N-alkylation of the parent meso-tetra (oxo-cyclohexadienylidene) porphyri…
An original synthetic approach to Au/TiO 2 nanosystems is developed. The adopted technique is based on the RF-sputtering of gold ( guest ) on porous titania xerogels ( host ) obtained by the sol−gel route. Such a combined synthetic pathway joins the peculiarities offered by the features of the sol−gel layers (porosity…
The hydrothermal synthesis and structural characterization of layered lanthanide silicates, K(3)[M(1-a)Ln(a)Si(3)O(8)(OH)(2)] (M = Y(3+), Tb(3+); Ln = Eu(3+), Er(3+), Tb(3+), and Gd(3+)), named AV-22 materials, are reported. The structure of these solids was elucidated by single-crystal (180 K) and powder X-ray diffra…
After adsorption on a silicon substrate, coiled multiwalled nanotubes retain a 3D structure with sections of freely suspended windings. Electrical gold contacts attached to the nanotubes turn out to be sensitive to vibrations (i.e., the contacts reveal a piezoresistive-like response). When exciting the nanotube windin…
The structure and energetics of thin water overlayers on the (101) surface of TiO(2)-anatase have been studied through first-principles molecular dynamics simulations at T = 160 K. At one monolayer coverage, H(2)O molecules are adsorbed at the 5-fold Ti sites (Ti(5c)), forming an ordered crystal-like 2D layer with no…
The chemical synthesis of polyaniline (PANI) is explored using tetrachloroaurate, AuCl 4 - . These studies provide a simple method for the oxidation of aniline by AuCl 4 - and simultaneous formation of bulk quantities of a PANI/Au composite. In situ UV/vis spectroscopy indicates that the rate of formation of gold coll…
Abstract For the homogeneous precipitation of hydrotalcite-like compounds (layered double hydroxides; LDHs), HMT (hexamethylenetetramine) was used and the conditions for obtaining the LDHs were investigated. The well-crystallized 1–5 μm LDHs were obtained in a pressure vessel after a 1-day treatment at 140 °C. The res…
[reaction: see text] Nineteen Mn(II) complexes were screened for the catalytic epoxidation of terminal olefins using peracetic acid. Few of these complexes are efficient catalysts at pH < 2, but many are effective at 1 mol % catalyst loading at pH 4. With 0.1 mol % loading, four complexes epoxidize 1-octene in approxi…
Luminescence temperature antiquenching (LTAQ) is observed for water-soluble CdTe quantum dots (QDs) capped with aminoethanethiol (AET). The efficient exciton emission (quantum efficiency of approximately 40% at 300 K) is quenched almost completely as the QD solutions are cooled to below 230 K and is fully recovered ar…