ABSTRACT
The rst commercial production of microporous membranes on a small scale started in 1930 together with the rst practical application of ion-exchange membranes and the development of the theory on ionic transport through charged membranes (Nunes and Peinemann 2001). However, until the late 1960s, membranes were used in a few laboratory and analytical applications, but not for industrial applications because they were too slow, too expensive, and too unselective. The seminal discovery that transformed membrane separation from a laboratory to an industrial process was the development of defect-free ultrathin cellulose acetate membranes by Loeb-Sourirajan process in the 1960s (Loeb and Sourirajan 1962; Mota et al. 2002).
