Nanoparticle synthesis at high production rates by flame spray pyrolysis

Scaling-up of nanoparticle synthesis by the versatile flame spray pyrolysis process at production rates up to 1.1 kg/h is investigated. Product silica powder is collected continuously in a baghouse filter unit which is cleaned periodically by air-pressure shocks. The effect of powder production rate, dispersion gas flow rate and precursor (hexamethyldisiloxane, HMDSO) concentration on product particle size, morphology and carbon content is investigated. Droplet size distributions of the cold spray are measured by laser diffraction, while N(2) adsorption (BET), transmission electron microscopy and thermogravimetric analysis coupled with a mass spectrometer are employed to characterize the product powder. The product primary particle size was precisely controlled from 10 to 75 run and compared to a well-established vapor-fed flame aerosol reactor. (C) 2003 Elsevier Science Ltd. All rights reserved.