Synthesis of Nanosized TiO2-SiO2 Particles in Microemulsions Stabilized by Anionic Surfactants
Nanosized TiO2-SiO2 particles were prepared by controlled hydrolysis of titanium tetraisopropoxide (TTIP) and tetraethylorthosilicate (TEOS) in microemulsions stabilized by anionic surfactants. Anionic surfactants ammonium carboxylate perfluoropolyether (PFPE-NH4) and sodium bis (2-ethylhexyl) sulfosuccinate (AOT) were used for formation of stabilized microemulsions in the W/C and W/O systems, respectively. The physical properties of the prepared particles have been investigated by TG-DTA, FT-IR, XRD and HRTEM. It is shown that the XRD pattern of the TiO2-SiO2 particles dried at 105 °C without calcination indicates amorphous. The particles calcined at 500 °C were identified as nanocrystalline anatase regardless of TTIP/TEOS molar ratio. The crystallite size of prepared particles decreased with increasing the silica content. From FT-IR analysis, the band for Ti-O-Si vibration was observed. The micrographs of HRTEM shown that the TiO2-SiO2 nanoparticles have a spherical morphology with a narrow size distribution and then the lattice fringe was 3.5 Å, which corresponds to the lattice spacing of (101) plane in the anatase phase.
Hyungsun Kim, Jian Feng Yang, Chuleol Hee Han, Somchai Thongtem and Soo Wohn Lee
M. S. Lee et al., "Synthesis of Nanosized TiO2-SiO2 Particles in Microemulsions Stabilized by Anionic Surfactants", Materials Science Forum, Vol. 695, pp. 602-605, 2011