Detailed Studies of Drying and Crack Formation in Aggregated Colloidal Suspensions
Brown, Lloyd Anthony
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/2142/82342
Description
Title
Detailed Studies of Drying and Crack Formation in Aggregated Colloidal Suspensions
Author(s)
Brown, Lloyd Anthony
Issue Date
2002
Doctoral Committee Chair(s)
Zukoski, Charles F.
Department of Study
Chemical Engineering
Discipline
Chemical Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Engineering, Chemical
Language
eng
Abstract
In this thesis we present evidence that particle interaction forces play an important role in the cumulative drying behavior of suspensions of aggregated colloidal particles. In particular, they control the shape and deformation behavior during drying of these suspensions. We identify a single dimensionless group Q¯ that can be used to predict drying behavior. We use a two-phase fluid model with the compressive yield stress constitutive equation to describe consolidation behavior in these systems. In the falling rate period we propose a simple diffusion mechanism that describes drying rate behavior during this period of drying. We describe the drying front that forms when the gas-liquid interface moves inside the porous bed by a single position of constant concentration. By combining the two-phase fluid model with the compressive yield stress constitutive equation and the diffusion model of drying in the falling rate period we characterize the development and evolution of stress in these aggregated systems as a function of moisture content. The volume fraction at which cracks begin has been identified as coinciding with the changeover from consolidation to de-saturation in these systems. Additionally we show that by adjusting the initial volume fraction of our suspensions, we can significantly alter their elastic properties so that the corresponding strain that these suspensions experience during drying can be significantly reduced.
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.
