Materials Literature
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Biodegradable polyure-thanes may be able to replace nondegradable polymers suchas polyethylene and polypropylene in fabrication ofpackaging films in near future as long as their mechanicalproperties are comparable to those of the common film-forming materials. Polyurethanes containing poly(ethylene glycol) (PEG) arein…
Glasses belonging to the x Fe 2 O 3 ·(100-x)[3 B 2 O 3 · BaO ] system, with 0≤x≤50 mol% were prepared and characterized by IR spectroscopy in order to obtain information about the influence of Fe 2 O 3 on the local structure in the 3 B 2 O 3 · BaO glass matrix. The mode in which both Fe 2 O 3 and BaO influences the st…
We investigated the variation of the emission properties of tetramethylammonium ion-containing faujasite zeolite treated with bis-(perfluoromethylsulfonyl)amide (PMS) as a function of the Nd(III)-loading level. The emission intensity increased with the Nd(III)-loading level. The emission decays did not follow simple f…
A theory for paramagnetic relaxation enhancement (PRE) in systems with S> 1 at low magnetic field is developed for the case when the fluctuations of zero-field splitting (ZFS) in the molecular frame are larger than the averaged ZFS. The validity limits of the new theory are discussed, and its performance is evaluated…
[reaction: see text] Acid-catalyzed reactions of 5-(2',3',4',5',6'-pentafluorophenyl)dipyrromethane with aryl aldehydes and of 5-(aryl)dipyrromethanes with 2,3,4,5,6-pentafluorobenzaldehyde allowed the preparation of a variety of meso-aryl [26]hexaphyrins.
The largest pi-conjugated dendrimers containing up to nine 10,15-dihydro-5H-diindeno[1,2-alpha;1',2';-c]fluorene (truxene) moieties have been prepared with good yields by repetitive Friedel-Crafts acetylation and acid-promoted cyclotrimerization reactions. An alternative approach to the convergent synthesis of desired…
We report the realization of a new multi-band-gap semiconductor. The highly mismatched alloy Zn1-yMnyOxTe1-x has been synthesized using the combination of oxygen ion implantation and pulsed laser melting. Incorporation of small quantities of isovalent oxygen leads to the formation of a narrow, oxygen-derived band of e…
We have used field-effect transistor (FET) devices with semiconducting single-walled carbon nanotubes (SWNTs) as the conducting channels to study interactions of aromatic compounds with SWNTs. Electronic detection occurs through charge-transfer effects, monitored as the change of the gate voltage ( V g ) dependence of…
A three-step seed-mediated growth method was used to make gold nanoparticles. Different surfactants, alkyltrimethylammonium bromides (C n TAB, n = 10, 12, 14, 16, and 18) and cetylpyridinium chloride (C 16 PC), were chosen as stabilizers. In general, it was found that as the length of the surfactant chain increased, t…
New electrooptical effect which is realized in nematic liquid crystal with high-density of defects is proposed. The electrooptical characteristics of electrooptical effect in high-defect nematic material is studied. The light modulator based on considered effect is elaborated and studied.
Abstract Crosslinked styrene‐butadiene and butadiene rubbers can efficiently be analyzed by liquid chromatography and FT‐IR spectroscopy. In a first step the vulcanizate is pyrolyzed under mild conditions. The resulting high molar mass fragments are extracted from the bulk material and analyzed by size exclusion chrom…
The reactivity of the cation radicals formed by oxidation of four 3,4-alkylenedioxypyrrole and 3,4-alkylenedioxythiophene monomers has been investigated by fast scan cyclic voltammetry, from the V/s to the kV/s range. The results show that all cation radicals react quickly as desired for electropolymerization and elec…
Triplet phases recorded from insulin crystals were used to measure the improvement of phases during model refinement and to quantify the contribution made by each step in the refinement. Conventional amplitude data were recorded to 1.5 A resolution from rhombohedral pig insulin crystals using 1.54 A Cu Kalpha radiatio…
A film sample of aromatic polyamide, or so-called Aramid, was subjected to grinding in air with calcium oxide (CaO) powder by using a planetary ball mill, to investigate its mechanochemical decomposition. The reaction was found to proceed with an increase in the period of grinding time, and all chlorine in the film wa…
The problem of pollution within Earth’s orbital environment has gained considerable recognition over the past decades. Determining adequate passive protection schemes is an unending process that attempts to meet different objectives for widely varying types of missions. Significant amounts of resources have been expen…
Abstract For Abstract see ChemInform Abstract in Full Text.
All of the electron paramagnetic resonance (EPR) and optical data relating to some of the basic nickel-related defects in diamond have been compared, as well as previously little considered information about the effects of spin–orbit coupling and the magnitude of the crystal field. New models are proposed for the EPR…
The perfect 60° glide dislocation in diamond serves as an example of how different aspects of dislocations can be modelled in an approach combining continuum elasticity theory with atomistic density-functional-based tight-binding calculations. After investigating the perfect 60° dislocation and its isolated Shockley p…
A method for improving crystallographic phases is presented that is based on the preferential occurrence of certain local patterns of electron density in macromolecular electron-density maps. The method focuses on the relationship between the value of electron density at a point in the map and the pattern of density s…
For biomedical and electronic applications, it is highly desirable to deposit smooth diamond films with crystal sizes in the nanoscale range. We present experimental results of chemical vapour deposition diamond growth from CH 4 with incremental substitution of H 2 with He or Ar gases; the concentrations of the inert…