Formation of Titanium oxide particles in supercritical CO₂

Abstract

The formation of sub-micro particles by supercritical fluids has been one of the promising research areas. In several cases the key of the process is the formation of very large surface areas. Among the other materials, titanium oxide is widely used as a pigment, a catalyst or a photoconductor In the ASES(Aerosol solvent extraction system) TiO2 was synthesized using supercritical carbon dioxide(SCCO2) and titanium isopropoxide(TIP). Synthesis methods of titanium isopropoxide(TIP) was characterized hydrolysis and thermal decomposition. In this study synthesis method was formed by SCCO2 residual H2O. The influence of the process pressure, nozzle size and concentration of the liquid solution depend on particle size. We performed various tests at pressures ranging between 80 and 150bar and ground a slight decrease of the mean particle size of TiO2 particles with increasing pressure. Also, influence of nozzle size (0.007~0.04 inch) and concentration of the liquid solution(0.1wt/wt%~2wt/wt%) was increase with lsolution concentration increase. About TiO2 size was from 200nm to 500nm.