Hafnium Oxide Doped Mesostructured Silica Films

Hafnium oxide doped silica films with ordered mesostructures were produced with hafnium:silicon ratios between 1:60 and 1:6. A surfactant\u2013hafnium alkoxide complex was synthesized and used as a template in a sol\u2013gel dip-coating process. Face-centred orthorhombic, 2D centred rectangular and lamellar films were formed by evaporation-induced self-assembly (EISA). The influence of subsequent heat treatment was studied by GISAXS and TEM. The surface and in-depth molecular composition of the films was studied by XPS.(\ua9 Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007

Syntheses and structures of [(Me₃N)₃SiNHLi]₄, (C₄H₈O)Al[NHSi(NMe₂)₃]₃, ((Me₂N)₃SiNH)₃Al and Li(THF)₂⁺[((Me₂N)₃SiNH)₄ Al]^-

The preparation of lithium tris(dimethylamino)silylamide, [(Me3N)3SiNHLi]4, 2, and its reaction with aluminium trichloride to give tris(dimethylamino)silylamino)(tetrahydrofuran)alane, (C4H8O)Al[NHSi(NMe2)3]3, 3, and bis(tetrahydrofuran)lithium tetrakis(tris(dimethylamino)silylamino)alanate, Li(THF)2+[((Me2N)3SiNH)4Al]−, 6, is reported, together with the crystal structures of 2, 3 and 6. Tris(dimethylamino)alane, ((Me2N)3SiNH)3Al, was obtained by reaction of tris(dimethylamino)silylamine with aluminium triethyl. The ammonolytic gelation of 3 to an imidoaluminosilicate gel is also described

Synthesis and characterization of orthorhombic, 2d-centered rectangular and lamellar iron oxide doped silica films

Iron oxide doped silica films and powders with highly ordered mesostructures of extraordinary temperature stability (up to 1000 °C) and iron loading of up to 6 atom% were produced by the use of novel iron alkoxide-coordinated surfactants. Wormhole-like, 2d-centered rectangular, orthorhombic and lamellar mesostructures were obtained by variation of the molar ratios of the metal–surfactant complexes. The influence of a subsequent heat treatment was studied by GI-SAXS, TEM, XRD, and nitrogen sorption techniques. The molecular composition of the films was studied by XPS and EXAFS

Nanostructured copper oxide on silica-zirconia mixed oxides by chemical implantation

A new route to chemical implantation of copper(II) N,N-dialkylcarbamato complexes on silica and nanostructured silica–zirconia matrices and subsequent thermal treatment (see scheme) is an efficient method of functionalizing the oxide matrices with nanostructured CuO. The materials have been characterized thoroughly and the effect of selected experimental parameters on the grafting reaction was investigated. N,N-Dialkylcarbamato complexes of copper(II), [Cu(O2CNR2)2] (R=All=allyl, C3H5; iPr, CH(CH3)2) were prepared with the aim of functionalizing silica and nanostructured silica–zirconia matrices. The mixed matrices for the grafting reactions were prepared by copolymerizing MAPTMS (methacryloxypropyltrimethoxysilane), the precursor for the silica matrix, with the zirconium tetranuclear derivative [Zr4O2(OMc)12] (OMc=methacrylate), the precursor for the zirconia nanoparticles. Suspension of the silica and silica–zirconia matrices in a solution of the copper dialkylcarbamate led to the functionalization of the respective substrates. The composition, microstructure, morphology, and physicochemical nature of the copper species grafted on the matrices were investigated by FTIR, X-ray photoelectron spectroscopy (XPS), EPR, X-ray absorption spectroscopy (XAS), XRD, TEM, and dinitrogen adsorption. The effect of selected experimental parameters (the nature of the copper precursor and of the matrix, grafting time, thermal treatment) on the grafting reaction was investigated. The Cu/Si ratio is increased by increasing the grafting time and the ZrO2–SiO2 matrix is more reactive to attack by the carbamato complexes than either prepared or commercial SiO2. After functionalization of the matrix, thermal treatment yielded nanostructured copper(II) oxide clusters, average diameter 12–15 nm, uniformly supported on the silica and on the silica–zirconia matrices

Experimental and Numerical Investigation of Metal Type and Thickness Effects on the Impact Resistance of Fiber Metal Laminates

The impact response of fiber metal laminates (FMLs), has been investigated with experiments and numerical simulations, which is reported in this article. Low-velocity impacts were carried out to study the effects of metal type and thickness within FMLs. Glare5-3/2 laminates with two aluminum layer thicknesses and a similar FML containing magnesium sheets were impacted by drop weight tests. Also, a major part of this study was to accomplish a dynamic non-linear transient analysis to study the impact response of FMLs using the commercial finite element (FE) analysis code ABAQUS. By reviewing different approaches of modeling constituents of an FML, it is shown that the appropriate selection of elements hasmore significant role than failure criterion to predict acceptable results for this type of laminate and loading. The good agreement obtained between experimental and numerical results verifies the possibility of relatively simpler simulation by FE-analysis to predict overall response of FMLs under impact loading.Aerspace Structures and MaterialsAerospace Engineerin