The dynamic properties of concentrated charge stabilized suspensions
Chen, Liang Bin
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/2142/22895
Description
Title
The dynamic properties of concentrated charge stabilized suspensions
Author(s)
Chen, Liang Bin
Issue Date
1992
Doctoral Committee Chair(s)
Zukoski, Charles F.
Department of Study
Chemical and Biomolecular Engineering
Discipline
Chemical and Biomolecular Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Engineering, Chemical
Language
eng
Abstract
The equilibrium properties and flow behaviors of concentrated charge stabilized suspensions are investigated in this dissertation. Monodispersed polystyrene particles with diameters ranging from 35 nm to 250 nm are used. Suspensions with volume fractions ranged from 0.10-0.62 are examined. Equilibrium elastic moduli and osmotic pressures are characterized. Rheological and osmotic pressure determinations of the location of the order/disorder phase transition are found to agree. Yielding and catastrophic shear thinning where the suspension viscosity decreases discontinuously with increasing shear stress are measured with both constant stress and constant strain rate rheometers.
The osmotic pressure and elastic modulus show volume fraction dependencies predicted by models using screened coulomb repulsive potential. The rheological studies show that suspensions exhibit a zero shear rate viscosity when disordered but show to have static and dynamic yield stresses when ordered. Superanomalous flow where shear stress is a decreasing function of shear rate is observed for the first time in ordered suspensions and is related to the structural transition through optical and small angle neutron scattering studies. Dynamic variables such as static yield stress, dynamic yield stress and critical stress are found to scale with the equilibrium modulus.
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.
