Figure 3.

Changes in CO₂ permeance and CO₂/N₂ selectivity on aging of PIM-1 TFC membranes with normal storage and methanol vapor storage. TFC membranes were prepared using branched PIM-1 B1 from (a) 3%, (b) 2%, and (c) 1% THF solutions and (d) 2% and (e) 1% CHCl₃ solutions and (f) using disubstituted PIM-1 D1 from 1% THF solution on PAN_01 support. TFC membranes were prepared using branched PIM-1 B2 from (g) 1.5% and (h) 0.7% THF solutions on PAN_02 support. After 28 days of the normal aging process, TFC membranes were further refreshed by storing in a methanol vapor atmosphere for 7 days. TFC membranes that had been tested previously and then retested are labeled as tested (blue), and TFC membranes that had not been tested previously are labeled as fresh (green).