COMPETITION BETWEEN TICL4 HYDROLYSIS AND OXIDATION AND ITS EFFECT ON PRODUCT TIO2 POWDER

Citation
Mk. Akhtar et al., COMPETITION BETWEEN TICL4 HYDROLYSIS AND OXIDATION AND ITS EFFECT ON PRODUCT TIO2 POWDER, AIChE journal, 40(7), 1994, pp. 1183-1192
Citations number
27
Categorie Soggetti
Engineering, Chemical
Journal title
ISSN journal
00011541
Volume
40
Issue
7
Year of publication
1994
Pages
1183 - 1192
Database
ISI
SICI code
0001-1541(1994)40:7<1183:CBTHAO>2.0.ZU;2-T
Abstract
The competition between hydrolysis and oxidation of TiCl4 during vapor -phase synthesis of titania powders was experimentally investigated. T he effects of reactor temperature, reactant mixing and H2O/TiCl4 ratio were studied in a hot wall aerosol flow reactor. The presence of wate r vapor resulted in rounded particles instead of the faceted ones obse rved in the absence of water; this effect was most pronounced at lower reactor temperatures. Mixing the water and TiCl4 vapor streams at low temperature resulted in anatase titania. Larger aggregates with small er primary particles were observed for powders synthesized in the pres ence of water vapor. The mixing temperature of the water and TiCl4 vap ors, as well as the H2O/TiCl4 ratios, did not affect the aggregate siz e or specific surface area. Analysis of micrographs of titania aggrega tes made in the presence of water revealed that the fractal dimension increased with process temperature.