Formation of uniform particles: Morphology and colloidal stability, and stable particle growth during precipitation from titanium alkoxides
Look, Jee-Loon
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/21510
Description
Title
Formation of uniform particles: Morphology and colloidal stability, and stable particle growth during precipitation from titanium alkoxides
Author(s)
Look, Jee-Loon
Issue Date
1991
Doctoral Committee Chair(s)
Zukoski, Charles F.
Department of Study
Chemical and Biomolecular Engineering
Engineering, Chemical
Engineering, Materials Science
Discipline
Chemical Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Chemistry, Physical
Engineering, Chemical
Engineering, Materials Science
Language
eng
Abstract
The mechanisms of formation of uniform particles from hydrolysis and condensation of titanium alkoxides are investigated. Evidence is presented suggesting two separate processes are determining the success of precipitating uniform particles: generating and maintaining a stable suspension throughout the reaction and a self sharpening growth mechanism to provide narrow size distribution. Factors that control particle morphology in the absence and presence of shear and the mechanisms of growth of colloidally stable suspensions are discussed. Two factors are identified which control colloidal stability and precipitate morphology during precipitation: interaction potentials of the precipitates and the nature of depositing species. A short range repulsive force is found to be required to explain the particles colloidal behavior. Under certain conditions, a solvation minimum develops in the pair potential which acts to localize particles at small separations. Under these conditions agglomeration occurs during the reaction.
HCl and NaCl are added to the precipitating system to alter precipitate surface charges and solution ionic strengths, and the resulting morphologies are discussed. Comparison of experimental results and model predictions is made for the effect of HCl and NaCl on the particle morphology with thermal motion in the absence of shear and with shear in the absence of thermal motion.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
