The precipitation of uniform silica particles through the controlled hydrolysis of silicon alkoxides

The formation of uniform silica particles by the alkoxide route has been investigated. Rates of chemical reactions involved in the precipitation are reported and linked to particle growth rates. Seeded growth experiments indicate that reactions between soluble species occur at rates that are independent of the size and number density of the seed particles. Estimates of hydrolyzed alkoxide concentrations based on solution conductivity suggest that the soluble silica concentration is above that required for nucleation until late in the reaction. These results are consistent with a particle growth mechanism whereby reactions occurring in solution proceed independently of the presence of particles, resulting in the formation of silica nuclei, which aggregate to form larger particles. This hypothesis has been further checked by carrying out precipitations at different electrolyte concentrations. While rates of hydrolysis and condensation are not substantially affected by NaCl concentrations up to 10$\sp{\rm -2}$ M, final particle size increases drastically.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Bogush, Gregory Harry

Contributors dc:contributor

• Zukoski, Charles F.

• Engineering, Chemical

Statement dc:rights

• Copyright 1990 Bogush, Gregory Harry

Language dc:language

eng

Identifier

AAI9114178
(UMI)AAI9114178

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/22008