Flame-coating of titania particles with silica
2005 (English)In: Journal of Materials Research, ISSN 0884-2914, E-ISSN 2044-5326, Vol. 20, no 5, 1336-1347 p.Article in journal (Refereed) Published
Silica/titania composite particles were prepared by co-oxidation of titanium-tetra-isopropoxide and hexamethyldisiloxane in a co-flow diffusion flame reactor. The influence of precursor composition on product powder characteristics was studied by x-ray diffraction, nitrogen adsorption, electron microscopy, elemental mapping, and energy-dispersive x-ray analysis. The flame temperature was measured by Fourier transform infrared spectroscopy. The evolution of composite particle morphology from ramified agglomerates to spot- or fully coated particles was investigated by thermophoretic sampling and transmission/scanning electron microscopy. At 40-60 wt% TiO2, particles with segregated regions of silica and titania were formed, while at 80 wt% TiO2 rough silica coatings were obtained. Rapid flame-quenching with a critical flow nozzle at 5 cm above the burner nearly halved the product particle size, changed its crystallinity from pure anatase to mostly rutile and resulted in smooth silica coatings on particles containing 80 wt% TiO2.
Place, publisher, year, edition, pages
Swiss Fed Inst Technol, Particle Technol Lab, Inst Proc Engn, Dept Mech & Proc Engn, CH-8092 Zurich, Switzerland. Swiss Fed Inst Technol, Dept Chem & Appl Biosci, Inorgan Chem Lab, CH-8093 Zurich, Switzerland., 2005. Vol. 20, no 5, 1336-1347 p.
IdentifiersURN: urn:nbn:se:uu:diva-317841DOI: 10.1557/JMR.2005.0160ISI: 000229293700033OAI: oai:DiVA.org:uu-317841DiVA: diva2:1083113