Materials Literature
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A series of polythiaarene derivatives has been synthesised and their redox properties studied. The charge stabilizing effect of the aryl sulfide groups that surround the central aromatic core promotes nucleophilic substitution and markedly facilitates radical anion formation, leading to remarkably mild reduction poten…
In this, the last of three articles on the optical absorption of electrons in a half-filled Peierls-distorted chain, we address the dimerized extended Hubbard model in the limit of a large on-site interaction U. When the Hubbard interaction is large compared with both the bandwidth W and the nearest-neighbour interact…
The thermal behaviour in oxygen and the cation distribution of manganese iron spinels Mn 3-x Fe x O 4 (0≤x≤3) obtained by a soft chemistry method have been determined by thermogravimetry and IR spectroscopy . The existence of two different cation distributions as function of composition x is established from a quantit…
Three natural diamond detectors (NDD) based spectrometry systems have been developed and used on TFTR to perform D–T neutron spectrum and flux measurements. DT neutrons interact with the NDD through the 12C(n, alpha)9Be reaction to produce a narrow peak in the pulse height distribution which has 2%–3% energy resolutio…
Ruthenium porphyrins catalyse oxygen transfer from 2,6-dichloropyridine N-oxide to steroids with retention of configuration at the asymmetric centre, giving novel steroids.
The acidic hydrolysis of triethoxyvinylsilane Si(C 2 H 3 )(OEt) 3 led to octavinyloctasilasesquioxane (C 2 H 3 SiO 1.5 ) 8 1 and to a transparent derived gel 2. Compound 1 was obtained as single crystals, suitable for X-ray analysis: trigonal, space group R, Z = 3, a = 13.533(2), c = 14.222(2) Å, γ = 120°. Disorder of…
The synthesis and structural and electrochemical properties of an electron deficient iron μ-oxo porphyrin dimer, (μ-oxo)bis[(2,3,12,13-tetrabromo-5,10,15,20- tetraphenylporphyrinatoiron(III)), represented as [(TPPBr 4 )Fe] 2 O, are reported. X-ray analysis indicates an Fe−O−Fe angle of 177.9(5)° and an interplanar dis…
The translational and rotational dynamics, including the translational−rotational coupling, of collagen in an aqueous 0.25 mg/mL solution of 0.1 N HCl were studied by polarized dynamic light scattering. An autocorrelator with variably spaced delayed times allowed computation of dynamic light-scattering intensity autoc…
New high efficiency thermoelectric materials with ZT values substantially larger than 1.0 have been recently developed. The successful development of a segmented thermoelectric generator utilizing a combination of state-of-the-art thermoelectric materials and these novel thermoelectric materials could result in a high…
The effect of iron content on the structure of xFe 2 O 3 (100-x)P 2 O 5 , (15≤x≤50), glasses was investigated by Raman spectroscopy and x-ray diffraction. The Raman spectra for these glasses indicate that the nature of the phosphate network changes from the chain like metaphosphate to the orthophosphate structure with…
We have studied a system of N=10 3 discotic particles with a central axial dipole using Monte Carlo computer simulations. We have investigated four temperatures corresponding to isotropic, nematic and columnar liquid-crystal phases determining the molecular and dipolar distributions and the length of the polar domains…
The objective of this study was to produce polylactic acid (PLA) microspheres containing bovine insulin as a sparingly water soluble model drug using a water-in-oil-in-water (w/o/w) emulsion solvent evaporation method. The preparative conditions were optimized. Employment of smaller internal aqueous phase volume (50 m…
The consequences of a glass transition occurring in one of the two phases formed by spinodal decomposition of a liquid mixture are investigated by numerical solution of the deterministic Cahn-Hilliard equation for two dimensions with a concentration-dependent mobility. The glass transition is modelled by a rapid decre…
A new building BLOCK approach to synthesis has been developed where functionalised norbornenes (BLOCK A) are coupled with functionalised cyclobutene epoxides (BLOCK B) to produce A + B structures of defined geometry; use of a dual (spacer) BLOCK allows the formation of large structures where crown ether, ligand and re…
A theory is proposed for the formation of superabundant vacancies in metal-hydrogen alloys, amounting to 10∼20 at%, considering hydrogen effects to decrease the formation energy of a vacancy by cluster formation and the configurational entropy of the system at high hydrogen concentrations. A formula derived for the va…
Six trinuclear linear complexes [LMnIII{µ-(niox)3MII}MnIIIL]2+ 1–3 and [LMnIV{µ-(niox)3MII}MnIVL]4+ 4–6 where M represents either Zn (1 and 4), Cu (2 and 5) or Mn (3 and 6), containing three cyclohexane-1,2-dione dioximate dianions (niox) as bridging ligands and 1,4,7-trimethyl-1,4,7-triazacyclononane (L) as the cappi…
A new versatile reagent, a perfluorosulfonate/trisilanol [(OH) 3 Si(CH 2 ) 3 (CF 2 ) 2 O(CF 2 ) 2 SO 3 - M + ], is synthesized and a series of surface bound strong solid acid catalysts developed which are active for catalyzing a range of reactions, for example alkene isomerization, alkylations and acylations.
The metal-free and nickel derivatives of hexaoctylpyridino[3,4]tribenzoporphyrazine generate conventional face-to-face aggregates in solution, exhibit columnar mesophases and form columnar assemblies upon evaporation of solutions. By contrast, the zinc derivative forms alternative edge-to-face complexes through axial…
Fibrous, powdered fibrous, and acid-washed celluloses, newsprint, and paper dunnage were examined by Pyromat micropyrolysis to determine volatile organic compound evolution kinetic parameters. For the cellulose samples, the interpolated T max values (temperature of maximum evolution rate for a constant heating rate) i…
Poly(ether ether ketone)/poly(ether diphenyl ether ketone) blend containing 30 wt% PEDEK was used to investigate the melting behaviour of immiscible PEEK/PEDEK blends. The results measured from differential scanning calorimetry (d.s.c.) and wide-angle X-ray diffraction (WAXD) showed that immiscible PEEK/PEDEK blends i…