Diffusion kinetics and phase separation phenomena during asymmetric membrane formation

In this thesis, both mathematical modeling and experimental analysis of the dynamics of the phase inversion process for forming asymmetric membrane structure have been carried out. A comprehensive model combining the evaporation and quench steps of phase inversion has been developed by using an improved numerical algorithm based on a modification of the jump mass balance equations. This approach enables accurate calculations of precipitation times and concentration profiles on both the polymer film and coagulation bath sides before the onset of phase separation. Results clearly show that final membrane structure is quite sensitive to the evaporation time with significant membrane property changes occurring as a result of a 20 second evaporation. Through a combination of decreased initial film thickness and a forced-convective evaporation step, both selectivity and permeability of the resulting membrane can be improved. In addition, increases in film surface area and initial solvent vapor in the casting atmosphere should lead to membranes having lower selectivity and higher permeability.

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

• Tsay, Chorng-Shyuan

Contributors dc:contributor

• McHugh, Anthony J.

• Engineering, Chemical

Statement dc:rights

• Copyright 1992 Tsay, Chorng-Shyuan

Language dc:language

eng

Identifier

AAI9215900
(UMI)AAI9215900

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/20185