Synthesis and characterization of Si-Al, Si-Ti, Si-Zr, Al-Zr, Al-Ti, and Al-Ti-Zr nanocomposites of lamellar or hexagonal structure

By using tetraethylortosilicate, titanium and zirconium tetrabutoxide, and aluminum sec-butoxide, as well as neutral 1,10 and 1,12 alkyldiamines or dodecyltrimethylammonium bromide as precursors, a series of six oxides, Si-Al, Si-Ti, Si-Zr, Al-Zr, Al-Ti, and Al-Ti-Zr, were obtained. These materials were characterized by infrared spectroscopy, thermogravimetry, Xray diffraction patterns, and scanning electron microscopy, Si-Ti, Si-Zr, and AI-Ti matrices exhibit a lamellar structure, whereas the others have a hexagonal nature. With the exception of the AI-Ti matrix for which grains with spheric morphology are observed, all the other matrices exhibited grains with amorphous nature, as observed by SEM micrographs. (C) 2001 Academic Press.