Premium
The second‐generation polysulfone gas‐separation membrane. II. The relationship between sol properties, gel macrovoids, and fiber selectivity
Author(s) -
Kesting R. E.,
Fritzsche A. K.,
Cruse C. A.,
Moore M. D.
Publication year - 1990
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1990.070400914
Subject(s) - polysulfone , selectivity , membrane , permeation , chemical engineering , polymer , coalescence (physics) , gas separation , materials science , polymer chemistry , intrinsic viscosity , fiber , chemistry , composite material , organic chemistry , catalysis , biochemistry , physics , astrobiology , engineering
All integrally skinned asymmetric membranes contain some defects which are attributable to the incomplete coalescence of the nodule aggregates of which the skin layer is composed. When such defects are small in size and few in number, they can be effectively sealed by coating with a highly permeable polymer. The resulting composite then exhibits the selectivity to gas permeation which is characteristic of the base polymer. Prior to their sealing, therefore, such membranes can be said to exhibit the potential for intrinsic selectivity. However, not all gas separation membranes can be effectively sealed. In the present study the relationship between sol properties, the presence of macrovoids in the substructure of the gel, and the subsequent failure of the fibers to achieve the potential for intrinsic selectivity are considered. Macrovoid‐free fibers with the potential for intrinsic selectivity can be prepared by the utilization of high viscosity, high total solids sols with low nonsolvent tolerance whose solvent vehicles consist of appropriate Lewis acid: base complexes.