ABSTRACT
The use of polymeric materials for gas separations has gone from a laboratory curiosity to a commercial reality within the past several decades. The technical foundations for the gas separation process were identified by Fick [1] and Graham [2] in the mid-19th century but were not exploited in any commercial sense until the mid-20th century. Starting with the liquid separations as applied to the techniques of microfiltration, hemodialysis, reverse osmosis, and ultrafiltration the technical aspects of large-scale membrane fabrication and operations were defined and the bases for subsequent developments in gas separations were quantified. A review by Lonsdale [3] gives his personal perspective on the early history of membrane technology and provides a good introduction to this broad topic. In a recent review Koros and Fleming [4] have focused on the commercial aspects of membrane-based gas separations, with particular emphasis on the preparation of thin separating layers.
