Aerosol synthesis of Ti-O powders via in-droplet hydrolysis of titanium alkoxide

A method to produce Ti-O powders by an in-droplet hydrolysis of metal alkoxide precursor is presented. Titanium n-tetrabutoxide, hydrolysis water, and acetic acid were included in the ethanolic precursor solution that was nebulized. The resulting aerosol was transported to a tubular flow reactor where the ethanol evaporation initiated a polycondensation reaction and solid particles were formed starting from droplet surface. Titanium hydrous oxide particles were obtained at 200 degreesC in atmospheric pressure of nitrogen and air. The collected powders were characterized by XRD, TG-SDTA, BET, SEM, TEM, and IR- spectroscopy, as well as with aerosol impactor. The as-produced powder particles were amorphous, smooth on the surface, and either spherical or deflated in shape. Aerodynamic mass mean diameter was 2.7 mum. Nanocrystalline TiO2 was obtained after thermal post-annealing for one hour. An expected tendency to convert to anatase crystalline phase up to 500 degreesC and subsequently to rutile phase up to 900 degreesC in the annealing was observed. The results show that the in-droplet hydrolysis is a viable method in preparing fine Ti-O powder particles with controlled properties. (C) 2001 Elsevier Science B.V. All rights reserved.