Materials Literature
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Two new charge-transfer hybrids with one or two ferrocenyl units covalently attached to a hexamolybdate cluster through an extended pi-conjugated bridge have been prepared using Pd-catalyzed coupling reactions on monoiodo- or diiodo-functionalized cluster substrates in over 60% yields. These hybrids have been characte…
The galleries of a Mg-Al layered double hydroxide have been functionalized by intercalation of (carboxymethyl)-beta-cyclodextrin cavities. The functionalized inorganic solid can adsorb iodine molecules from vapor as well as nonaqueous and aqueous solutions. The adsorbed iodine complexes with the grafted cyclodextrin c…
In the present work we report x-ray powder diffraction measurements of Sr2CaWO6 and Sr2MgWO6, at different temperatures. The crystal structures at room temperature of both compounds are determined; and results showing the existence of phase transitions in them are presented. For the structure at room temperature of th…
A study aimed at investigating the process of formation of hybrid nanocomposites consisting of a thin polyimide layer containing copper nanoparticles of varying sizes (3−10 nm in diameter) is described. In this system, precursor layers in which copper ions are fully or modestly doped in a chemically modified polyimide…
Proline dehydrogenase (PRODH) catalyzes the first step of proline catabolism, the flavin-dependent oxidation of proline to Delta(1)-pyrroline-5-carboxylate. Here we present a structure-based study of the PRODH active site of the multifunctional Escherichia coli proline utilization A (PutA) protein using X-ray crystall…
A new family of molecule-based magnets of general formula V[TCNQR(2)](2).zCH(2)Cl(2) has been synthesized and characterized (TCNQ = 7,7,8,8-tetracyano-p-quinodimethane; R = H, Br, Me, Et, i-Pr, OMe, OEt, and OPh). In addition, solid solutions of V[TCNQ](x)()[TCNQ(OEt)(2)](2)(-)(x)().zCH(2)Cl(2) composition have been p…
The two flavodoxins (YkuN and YkuP) from Bacillus subtilis have been cloned, overexpressed in Escherichia coli and purified. DNA sequencing, mass spectrometry, and flavin-binding properties showed that both YkuN and YkuP were typical short-chain flavodoxins (158 and 151 amino acids, respectively) and that an error in…
This paper describes the buildup of hydrogen-bonding-directed poly(4-vinylpyridine)/poly(4-vinylphenol) (PVPy/PVPh) multilayer film that was fabricated by layer-by-layer (LbL) assembly of PVPy and PVPh from an ethanol solution. UV-visible spectroscopy and Fourier transform infrared (FT-IR) spectroscopy revealed a unif…
A light-driven process for fabrication of spatially controlled nanoporous polymer films was demonstrated with a new diblock copolymer/small molecule additive system. Poly(α-methylstyrene- b -4-hydroxystyrene) was designed and synthesized with one block functioning as a high-resolution negative-tone photoresist and the…
Cobalt oxide (Co 3 O 4 ) nanotubes were synthesized by calcining cobalt nanowires embedded in an anodic alumina template (AAT) in air. The morphologies and phases of the nanowires/nanotubes were studied by transmission electron microscope (TEM) and x-ray diffraction (XRD) respectively. A hypothesis of the tube formati…
In this study, single-walled carbon nanotube-based sensors are proposed for measuring strain and pressure at the nanoscale. The principle of sensing is based on the resonant frequency shift of a carbon nanotube resonator when it is subjected to a strain resulting from external loading. The carbon nanotube in a bridged…
The effect of synthesis and reaction conditions on the structure and activity of Au clusters supported on nanocrystalline and mesoporous TiO 2 was investigated. X-ray absorption spectroscopy was applied to correlate the particle size and the oxidation state with several parameters, such as pH of the precursor solution…
Nanotechnology is an area receiving increasing attention as progress is made towards tailoring the morphology of polymeric biomaterial for a variety of applications. In the present study an attempt was made to electrospin poly(L-lactide- co -glycolide) biodegradable polymer nanofibres. In this process, polymer fibres…
CdSe and CdSe@CdS semiconductor nanocrystals have been synthesized in aqueous solutions, using sodium citrate as a stabilizer. Although initially these quantum dots display photoluminescence with very low quantum yields, upon prolonged illumination with visible light, enhancements up to 5000% have been measured. This…
To better understand protein/material and cell/material interactions at the submolecular level, well-defined polymer brushes consisting of poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) on silicon wafers were prepared by atom transfer radical polymerization (ATRP). Silicon wafers were treated with 3-(2-bromoiso…
Four new disubstituted propylenedioxythiophene polymers have been synthesized by Grignard metathesis on the 1−5 g scale. All polymers were found to be soluble in chloroform, methylene chloride, toluene, and tetrahydrofuran and were fully structurally characterized having GPC determined number-average molecular weights…
A strong photoluminescence enhancement effect of illumination on CdTe nanocrystals stabilized by thioglycolic acid (TGA) was observed. Under optimized conditions, the fluorescence quantum yield of CdTe nanocrystals in aqueous solution reached 85% at room temperature. Optical measurements indicated that the photodegrad…
Using high-resolution x-ray scattering in the presence of an applied current, we report evidence for a dynamical decoupling between the two NbSe3 charge-density waves (CDWs), Q1 (T(C1)=145 K) and Q2 (T(C2)=59 K), coexisting below T(C2). Simultaneous and oppositely directed shifts of the relevant CDW superlattice spots…
The magnetocaloric effect and the order of magnetic transition in La(Fe 0.88 Al 0.12 ) 13 C x interstitial compounds have been investigated by means of magnetic measurements and Mössbauer spectroscopy. With increasing carbon content from x = 0.2 to 0.6, the maximum magnetic entropy change decreases from 9.6 to 8.3 J k…
A parallel analysis of the polymorphic behavior and mechanical properties of syndiotactic polypropylene samples with different stereoregularity and crystallized in the helical form and in the trans-planar mesomorphic form, stretched at room temperature and at 4 °C, is reported. Oriented fibers show good elastic proper…