ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
A series of dense films and membranes was prepared using different processes; their surface morphology was investigated by transmission electron microscopy using the replication technique. On the basis of TEM results, SEM observations of cross sections of membranes and gas-separation properties of membranes, two kinds of membrane morphology are evidenced in relation to their preparation conditions and final properties. The first one gives an ultrafiltration-type membrane. Large nodules are observed on the surface of the membranes. It is suggested that these are formed by liquid-liquid separation that occurs by nucleation and growth of the polymer-rich phase. The second one yields gas-separation-type membranes. No nodules are evident at the surface of these membranes. The skin is formed by a step that concentrates the initial solution. It is followed by the transformation of the solution in the glassy state. Liquid - liquid separation takes place below the first skin layers by nucleation and growth of the polymer-poor phase. © 1993 John Wiley & Sons, Inc.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1993.070470909
Permalink