Patent ID: 7422623

Claim:
A membrane for fluid separation prepared by a process comprising the steps of: a) providing a polyimide polymer comprising a plurality of first repeating units of a formula (I), wherein said formula (I) is: in which R 1 of said formula (I) is a moiety having a composition selected from the group consisting of a formula (A), a formula (B), a formula (C), and mixtures thereof, wherein said formula (A), said formula (B), and said formula (C) are: and in which R 2 of said formula (I) is a moiety having a composition selected from the group consisting of a formula (Q), a formula (S), a formula (T), and mixtures thereof, wherein said formula (Q), said formula (S), and said formula (T) are: in which Z of said formula (T) is a moiety having a composition selected from the group consisting of a formula (L), a formula (M), a formula (N), and mixtures thereof, wherein said formula (L), said formula (M), and said formula (N) are: b) annealing said polyimide polymer to form an annealed polymer; c) synthesizing a concentrated solution, wherein said concentrated solution comprises a solvent and said annealed polyimide polymer; and d) forming a membrane.