Materials Literature
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The reaction between N2O and CH4 over an Fe ion-exchanged BEA zeolite (Fe-BEA) catalyst was studied by using a pulse reaction technique, temperature-programmed desorption (TPD) and infrared (IR) spectroscopy. N2O readily reacted with CH4 in the presence of an N2O + CH4 mixture above 200 °C, while both the O2 + CH4 rea…
There is a clinical need for the tissue engineering of a small diameter blood vessel substitute. Ideally such a vascular substitute should possess the functional attributes of the native vessel which it will replace. This means not only having the appropriate mechanical properties, but also being non-thrombogenic and…
Meso-organisation of SiO2 and TiO2 particles prepared by spray drying have been for the first time analysed through in-situ SAXS. Both processing and chemical parameters are critical to obtain meso-organised spheres.
Abstract An overview of the metal-mediated synthesis and use of nanosized metallodendrimers is given with emphasis on electron-transfer processes (molecular batteries consisting in dendrimers decorated with a large number of equivalent redox-active centers) and catalytic reactions (electron-transfer-chain catalytic sy…
The passivation behavior of 20, 30 and 40 wt. %) alloys and their individual metal components was studied in borate buffer, pH 9.2, by a combination of electrochemical measurements and X-ray photoelectron spectroscopy (XPS). In general, the shape of cyclic voltammograms of all four alloys resembles that of copper more…
A simple shape-memory-alloy (SMA) model to simulate the superelastic behavior as well as the shape memory effect is proposed. It considers only the transformations from austenite to single-variant martensite and from single-variant martensite to austenite, taking into account the ine uence of the temperature in the co…
The solvothermal reaction, at 200 °C, of vanadium pentoxide and lithium hydroxide in acetic acid or ethylene glycol leads to the formation of vanadyl acetate and vanadyl glycolate respectively. The structure of the acetate contains vanadium in octahedral coordination whereas the glycolate contains VO5 square pyramids.…
The synthesis of the potentially nonadentate ligand 1,4,7-tris[(6-carboxypyridin-2-yl)methyl]-1,4,7-triazacyclononane (H3tpatcn), a new derivative of 1,4,7-triazacyclononane N-functionalised with three pyridinecarboxylate arms, is described. The complexes of four lanthanide ions (Nd, Eu, Gd, Lu) of this ligand have be…
Ab initio (density functional theory) relaxation of nanocrystalline diamond structures of cubic, octahedral and cuboctahedral morphologies, up to about 1.3 nm in diameter are presented. Results show that the crystal morphology plays an important role in the structural stability, in the absence of external fields. Our…
Doped ceria (CeO2) compounds are fluorite type oxides which show oxide ionic conductivity higher than yttria stabilized zirconia, in oxidizing atmosphere. As a consequence of this, considerable interest has been shown in application of these materials for ‘low temperature operation (500–650 8C)’ of solid oxide fuel ce…
An improved theoretical analysis on the electrical characteristics of ferroelectric memory field-effect transistor (FeMFET) is given. First, we propose a new analytical expression for the polarization versus electric field (P-E) for the ferroelectric material. It is determined by one parameter and explicitly includes…
Eu-doped BaTiO3 thin films with a pseudo-cubic perovskite structure were successfully fabricated on magnesia substrates at low temperature by using a high-concentration sol–gel process, in which the newly developed gel-aging process on substrate was employed. Film microstructure, crystallinity, sintering properties an…
Samples of ice XII made on isobaric heating of high-density amorphous ice (HDA) were recovered at 77 K and characterized by X-ray diffraction. Studies by differential scanning calorimetry (DSC) revealed, in addition to the intense exotherm from the ice XII → cubic ice transition, on heating at 30 K min−1 a reversible…
Pyrochlore-type bismuth tin oxide, Bi2Sn2O7, is a technologically important material used in applications such as catalysis and gas sensing. Its room temperature structure has been solved by a method of simulated annealing of combined X-ray and neutron diffraction data, followed by Rietveld refinement. With 176 crysta…
We present the temperature-dependent thermolysis of siloxy-substituted ZnO single-source precursors into zinc and zinc oxide, respectively. The solid-state pyrolysis at low temperatures leads to the formation of ZnO powder with a very high surface area whereas the thermolysis in solution yields ZnO colloids. The mater…
The reaction of the neutral triangle [Mn3O(O2CR)6(L)3] with 1,1,1-tris(hydroxymethyl)ethane (H3thme) affords novel dodecanuclear and octanuclear manganese complexes with unusual ladder-like cores built from edge-sharing triangles.
The preparation, crystal structures and magnetic properties of four different manganese(II) compounds of formula [Mn(bipym)Cl2]n·2nH2O (1), [Mn2(dpp)2(H2O)2Cl4]·2H2O (2), [Mn(dpp)(H2O)2]n(ClO4)2n·1.5nH2O (3) and [Mn(dpp)(dca)2]n (4) [bipym = 2,2′-bipyrimidine, dpp = 2,3-bis(2-pyridyl)pyrazine and dca = dicyanamide ani…
A series of octupolar molecules derived from the boroxine framework were designed and their optical nonlinearities were investigated by performing harmonic light scattering experiments in solution; the molecules were found to combine excellent transparency in the near UV-visible region (lambdamax < or = 280 nm) and si…
The 4'-dimethylaminoflavylium ion in aqueous solution undergoes an intricate network of chemical reactions controlled by pH and light excitation. It is shown that nine different forms are involved, including two species that are not present in previously investigated compounds of the flavylium family. The thermodynami…
We have synthesized low-molecular-weight, triazole ring-appended 2'-deoxyuridine hydrogelators that gelate pure water at a concentration as low as 0.2 wt% and these compounds display different aggregation and network structures as evidenced by their SEM images, FTIR spectra and minimum gel concentrations.