Structure Formation Phenomena During Phase Inversion. II. Semiflexible Polymers and Liquid Crystallinity

Abstract

The issue of isotropic-anisotropic equilibria contributions to structure formation of phase inversion (PI) membranes of semiflexible polymers such as cellulose derivatives is addressed. Two types of ternary phase diagrams pertinent to the PI of semiflexible polymer dopes are suggested, and modes of phase separation that control structure formation are described. Alternative interpretations for certain earlier structural observations in cellulose acetate (CA) membranes are proposed. Discussions of the lyotropic polymer gelation modes and the effect of glass formation on the progress of PI structural transformations are included.

Keywords:

• Cellulose acetate
• Glass transition
• Liquid crystallinity
• Lyotropic gelation
• Membrane structure formation
• Phase inversion
• Semiflexible polymer

ACKNOWLEDGMENT

Prof. P. W. Voorhees of Northwestern University and Mr. A. Lapatas and Mr. L. Peristeras of NCSR Demokritos are thanked for useful discussions and/or help. This work is dedicated to the memory of Jeffrey Lee Pierce.