Materials Literature
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We demonstrate a potentially useful method of generating an SiO2 morphology, in situ, with interpenetrating polymer networks (IPN) chemistry. Organic/inorganic IPNs were synthesized with an organic phase made of epoxy resin and an SiO2 phase made by sol—gel chemistry. The two types of polymerization used were sequenti…
Metallic vanadium powder was dissolved in a hydrogen peroxide solution, yielding a hydrosol based on a polyvanadate. A polycrystalline thin film of VO 2 was fabricated on a fused silica substrate by spin-coating using this hydrosol followed by reduction in hydrogen and additional post-annealing in a nitrogen atmospher…
Abstract The polyiminophosphazene bases Et‐P 2 and t ‐Bu‐P 4 were used as a promoter for ethylene oxide and siloxane polymerizations. Initiation by an alcohol in combination with t ‐Bu‐P 4 lead to an extremely rapid polymerization reaction of octamethylcyclotetrasiloxane. In the case of ethylene oxide, well‐defined po…
In this study, we describe a distinct nematic liquid crystal with polar ordering which is formed from the polar rod-like aromatic copolyester comprising 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid. The polarity in the nematic phase appears along the nematic director as determined by second-harmonic generation…
The martensitic β1→ β′1 transformation in Ni2MnGa Heusler alloy and B2 → R transformations in two Ti‒Ni‒Fe alloys have been studied and the latent heats of these transformations measured. The shifts of martensitic transformation temperatures under the action of applied hydrostatic pressure have been determined. The ex…
Abstract For the calculation and the drawing of Dirichlet domains and coordination polyhedra in crystal structures or point sets two programs – DIDO95 and VOID95 – have been derived. A third program – DEMODIDO – shows how the Dirichlet domain of a point changes if the metrical parameters or the coordinates vary along…
The crystal structure of lead tetraborate, PbO.2B 2 O 3 , has been refined using single-crystal X-ray diffraction data (Mo K α radiation, λ = 0.71069 Å). Crystal data at room temperature: M r = 362.43, orthorhombic, P 2 1 nm ( C 7 2 v ), a = 4.251 (2), b = 4.463 (3), c = 10.860 (3) Å, V = 206.04 Å 3 with Z = 2, μ = 40…
Assignment of the peaks near 485 em-I in vibrational spectra ofSi02-M7;:;Al02(where M = an alkali or alkaline earth element) glasses to v,(T-O-T) modes in four-membered rings was tested with molecular orbital calculations. Potential energy minima of cyclic (HsSimAln012)n- (where m + n = 4), Li2HsSi2A12012, Mg2HsA14012…
Dielectric and rheological measurements are reported on the effect of cure temperature on the water absorption of tris[(2,3-epoxypropoxy)phenyl] methane cured with a 1 : 1 stoichiometric ratio of 4,4′-diaminodiphenylsulphone. Analysis of the water absorption characteristics of these materials using a combination of di…
The Rodrigues parameterization of rotations offers an intuitively simple space which enables visualization of the geometric configuration of orientations and misorientations. Recent efforts have concentrated on promoting the use of Rodrigues vectors for orientation parameterization. In the present work a procedure for…
The transport behavior of aromatic hydrocarbons in crosslinked nitrile rubber (NBR) membranes has been studied in the temperature interval of 28°–70°C. NBR was cured by different vulcanizing techniques, viz., efficient, conventional, peroxide, and mixed. The peroxide system showed the lowest solvent uptake; and the co…
Abstract Copolymerization of γ‐butyrolactone (γBL) with ε‐caprolactone (εCL) initiated with aluminium isopropoxide trimer ([Al(O i Pr) 3 ] 3 , (A 3 )) is described. Copolymers with molecular weights ( M n ) up to 3 · 10 4 and containing up to 43 mol‐% repeating units derived from γBL are prepared. Their molecular weig…
Electrochemical oscillations at silicon electrodes anodized in hydrofluoric acid are a well known but poorly understood phenomena. It is less well known that potential oscillations are also observable during anodic oxidation in fluoride‐free electrolytes. In situ measurements of stress, as well as x‐ray reflectometry,…
Abstract Three natural spinels of different places of occurrence and compositions were investigated by means of microprobe chemical analysis, single crystal X-ray diffraction and Mössbauer spectroscopy. All cation distributions between T and M sites were calculated from microprobe and XRD experimental data, by means o…
Abstract The rotational molding processing method for plastics is steadily expanding its product range and market areas. However, a drawback of the process has always been the surface pin‐holes and internal bubbles that occur in the products because of the inherent nature of the process. In an attempt to alleviate thi…
Several new, more highly corrosion resistant titanium alloys containing a nominal 0.1 weight per cent of ruthenium have been developed and evaluated for industrial service in corrosive environments. These improved ruthenium-enhanced α, α-β and β titanium alloys are lower in cost than the corresponding palladium-contai…
Ammonium and borate substituents polarize π-electron systems, which then exhibit internal CT bands in the UV/Vis spectrum. These systems (for example 1) are distinctly more transparent than analogous push–pull-substituted compounds. Since their first-order hyperpolarizabilities are nevertheless similar to push–pull co…
The mean square displacement of protein hydration water has been found to increase nonlinearly in time, as observed for long times, by molecular dynamics simulations at low hydration levels and in proximity of the protein surface at full hydration. While such an anomalous diffusion is traced back to the more general p…
The crystal structure of FeAlO 3 has been determined at T = 298 K by neutron diffraction, using polycrystalline samples prepared in a high state of purity. The space group is Pna 2 1 , Z = 8; a = 4.9839 (1), b = 8.5544 (2), c = 9.2413 (2) Å. The structure, which is isomorphous to that of FeGaO 3 , can be described as…
The concentration dependence of optical phonons in the ${\mathrm{TiO}}_{2}$-${\mathrm{SnO}}_{2}$ system whose phase diagram exhibits a miscibility gap, has been studied by Raman scattering and Fourier-transform infrared spectroscopy. X-ray diffraction confirmed that the mixed oxides ${\mathrm{Ti}}_{1\mathrm{\ensuremat…