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Highlights: [•] SBA-16 based monoliths containing Fe/Co nanophases were prepared by sol–gel. [•] Monoliths are stable upon calcination at 500°C and reduction at 800°C. [•] Superparamagnetic fcc Co–SBA-16 nanocomposites can be obtained. [ABSTRACT FROM AUTHOR]

Abstract: Mesoporous silica films with controlled porosity were utilized as the host matrices to prepare FeCo–SiO2 nanocomposites through an impregnation process. The mesoporous silica films were first impregnated with a solution containing Co(II) and Fe(III) ions and then submitted to a reduction treatment under H2 flow. FeCo nanocrystals growth took place inside the mesopores, and their monodisperse size was dictated only by the size of the mesopores. We illustrate this process by the use of two different silica film matrices having different pore size and mesophase symmetry as the templates for the growth of FeCo alloy nanocrystals. The films and the nanocomposite samples were investigated by grazing-incidence small-angle X-ray scattering, X-ray diffraction and transmission electron microscopy. Unimpregnated mesoporous silica samples before and after the same thermal reduction treatment were also studied in order to investigate the mesopore structure variation upon the reduction treatment. [Copyright &y& Elsevier]

Abstract: Highly ordered silica and hybrid organic–inorganic membranes have been obtained through a slow and controlled solvent evaporation in the presence of a triblock copolymer as the structure-directing agent. Crack-free mesostructured membranes of large dimensions have been prepared. The mesophase is self-organized into a periodic cubic structure, , and consists of macroscopic mesostructured domains that maintain the out-of-plane order throughout the material. After calcination at 350°C the membranes remain transparent even though they break in fragments of some centimeters. Different techniques have been employed to characterize the mesoporous materials: small angle X-ray scattering (SAXS) using synchrotron radiation and transmission electron microscopy to study the porous structure, Fourier transform infrared spectroscopy (FTIR) in vacuum at different partial pressures to investigate the nature of the pore surface. SAXS analysis has been used to map the whole membrane, revealing some differences in the pore organization that can be attributed to a gradient in the evaporation rate. The infrared measurements at different partial pressures have elucidated the mechanism of water adsorption–desorption on the pore surface. The changes of the FTIR spectra with different partial pressure have demonstrated that the pore surface is covered by a layer of molecular water that is hydrogen bonded to silanol species. [Copyright &y& Elsevier]