Materials Literature
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Eight new compounds α- and β-MxHy[(CpTi)3XW9O37]·nH2O (M = K+, x = 4, y = 3; M = NBu4+, x = 7, y = 0; X = Si, Ge) have been synthesized from vacant heteropolytungstate precursors α-, β-[XW9O34]10− (X = Si, Ge) and Cp2TiCl2. The products were characterized by elemental analysis, IR, UV–VIS spectroscopy, 1H NMR, 183W NM…
The crystal structures of [Ph4P]2[M(mnt)2] (M = Zn 1, Cu 2 or Ni 3), [Ph4P][M(mnt)2] (M = Cu 4 or Ni 5), [Ph4P]2[{M(mnt)2}2] (M = Co 6 or Fe 7), [Ph4P]2[M(mnt)3] (M = Fe 8 or Cr 10) and [Ph4P]3[Cr(mnt)3] 9 {mnt = maleonitriledithiolate, [S2C2(CN)2]2−} have been determined to investigate the packing and supramolecular…
The polymerization of aldehydes has played a considerable role in the progress of chain reaction polymerization and has significantly contributed to our knowledge of polymer science. Polyformaldehyde, as homopolymer and copolymer, plays an important role as a significant niche product in engineering plastics use. High…
The first structural characterisation of a heterocyclic free radical in all phases has been achieved. 4,5-Bis(trifluoromethyl)-1,3,2-dithiazol-2-yl, [CF3CSNSCCF3]˙ 4d, a 7π radical, was prepared quantitatively on reduction of [4d][AsF6] with various reducing agents. It is a blue gas over a green paramagnetic liquid [1…
Voltage-modulated scanning force microscopy has been employed to investigate the dynamics of ferroelectric domains as a function of time and temperature in triglycine sulfate (TGS) single crystals. Branching of the domain structure and nucleation of fine domain patterns by internal fields of thermal origin have been d…
Crystalline undoped and thulium doped yttrium oxide (Y2O3) thin films have been grown by the pulsed laser deposition (PLD) technique on various single-crystal substrates heated at 700 °C. X-Ray diffraction (XRD) analysis showed that the orientations of the films depended on the substrate and on the oxygen pressure. Th…
Modification of poly(phthalazinone ether sulfone ketone) (PPESK) by sulfonation with concentrated or fuming sulfuric acid as sulfonation agents was carried out to prepare membrane materials with increased hydrophilicity and potentially increased fouling resistance. Sulfonated PPESK (SPPESK) copolymers, with a degree o…
In order to raise the turbine inlet gas temperature to improve thermal efficiency of gas turbines, turbine blade and vane materials are required to have high creep rupture strengths. In the present study, a new single crystal superalloy with a moderate Re addition (2.4wt%) has been developed. The alloy shows a higher…
Adamantyl-terminated poly(propylene imine) dendrimers 1–5 were dissolved in water in the presence of β-cyclodextrin through strong non-covalent interaction between the β-cyclodextrin and adamantyl groups. The solubilization of the dendrimer by β-cyclodextrin is most effective at pH = 2, because at this pH there is com…
Poly(amic acid) was synthesized with a low-temperature solution polymerization of 3,3′-dihydroxybenzidine and pyromellitic dianhydride in N,N-dimethylacetamide. The cast films were thermally treated at various temperatures. The polyimide containing the hydroxyl group was rearranged by decarboxylation, resulting in a f…
Optically isotropic thin films (0.5 μm) of an amorphous side-chain copolymer containing 10% azobenzene moieties and 90% meso-azobenzene groups (K1-10 sample) were irradiated by two interfering orthogonal (±45°) or parallel (p + p) linearly polarized laser beams; permanent holographic diffraction gratings were thus ins…
The hydrothermal chemistry of the Ni(II)/molybdate/3,3′-bipyridine system exhibits pronounced pH dependence, such that under basic conditions a 2-D material with embedded clusters [{Ni(3,3′-bpy)2}2Mo4O14] 1 is observed, while under acidic conditions the 2-D bimetallic oxide network of [Ni(3,3′-Hbpy)Mo4O13(OH)] 2 is is…
Many concrete structures may be submitted to high rate dynamic loadings (impacts, explosions, etc.). So, it is necessary to know the behaviour of this material in order to predict the response of the structure. Under dynamic loading an increase of apparent compressive strength is observed. This may be due to a rheolog…
Polyimide (PI) materials with a low coefficient of thermal expansion (CTE) while still retaining high strength and toughness are desirable in various applications. In this study a sol–gel process was used to incorporate silica into homopolyimides and copolyimides with highly rigid structures in an attempt to pursue th…
Surface-enhanced Raman scattering (SERS) of hypoxanthine (HX) molecule on silver colloid confirms that the molecule in the surface adsorbed state exists as [keto–N9 H9] form at acidic and normal pH but as [enol–O6 H1, N9 H9] form at alkaline pH. It is substantiated by the appearance of an intense carbonyl stretching m…
In this study, the formulation and process parameters that determine successful production and long-term stability of freeze-dried poly(lactic acid) (PLA) nanoparticles with "hairy-like" poly(ethylene oxide) (PEO) surfaces were investigated. Nanoparticles with grafted (covalently bound) PEO coatings were produced by t…
The pathway of cysteine biosynthesis in archaea is still unexplored. Complementation of a cysteine auxotrophic Escherichia coli strain NK3 led to the isolation of the Methanosarcina barkeri cysK gene [encoding O-acetylserine (thiol)-lyase-A], which displays great similarity to bacterial cysK genes. Adjacent to cysK is…
Polyurea microcapsules were formed by carrying out an interfacial polycondensation reaction in emulsion globules between various diisocyanates and ethylenediamine to investigate the effects of the chemical structure on various characteristics. FTIR showed that very reactive aromatic 2,4-toulene diisocyanate produced m…
The behavior of sealed and unsealed porous aluminum oxide films during aging and autosealing‐aging in various media is studied. The quality of the anodic layers and the degree of sealing and aging are assessed. The results of electrochemical impedance spectroscopy are compared with those provided by standard quality c…
Zinc(II)-5,15-diarylporphyrins have been effectively polymerized to give poly(Zn(II)-porphyrinylene) in high yields in the reaction with 1.5 equiv. AgPF6 in CHCl3 either in the presence of 0.5% N,N-dimethylacetamide or upon heating.