Patent ID: 7950529

Claim:
A membrane for fluid separation made of a material comprising a blend of: a polyimide polymer; and a polyimidazole polymer; wherein said polyimide polymer comprises a plurality of repeating units represented by formula (I) wherein each R 2 is independently selected from the group consisting of formula (A), formula (B), and formula (C) wherein each R 1 is independently selected from the group consisting of formula (Q), formula (S), and formula (T) wherein each Z is independently selected from the group consisting of formula (L), formula (M), and formula (N) wherein said polyimidazole polymer comprises repeating units selected from the group consisting of formula (IIa) and formula (IIb) wherein R 3 of formula (IIa) is an aromatic group, the two nitrogen atoms of formula (IIa) being bonded to adjacent carbon atoms of R 3 ; wherein R 4 of formula (IIb) is an aromatic group, the two N′ atoms being bonded to one set of adjacent carbon atoms of R 4 , the two N″ atoms being bonded to another set of adjacent carbon atoms of R 4 ; and wherein R 5 of formula (IIb) is an aromatic, aliphatic or heterocyclic group.